Messages in AirborneWindEnergy group.                     AWES5205to5254 Page 2 of 440.

Group: AirborneWindEnergy Message: 5205 From: Doug Date: 12/27/2011
Subject: Re: Betz' limit, new visits

Group: AirborneWindEnergy Message: 5206 From: Joe Faust Date: 12/27/2011
Subject: News sample re: Makani Power

Group: AirborneWindEnergy Message: 5207 From: harry valentine Date: 12/27/2011
Subject: Re: Betz' limit, new visits

Group: AirborneWindEnergy Message: 5208 From: Joe Faust Date: 12/27/2011
Subject: Re: Climbing Kites in Calm CKC

Group: AirborneWindEnergy Message: 5209 From: Joe Faust Date: 12/27/2011
Subject: Re: Climbing Kites in Calm CKC

Group: AirborneWindEnergy Message: 5210 From: dave santos Date: 12/27/2011
Subject: Step-Towing Scale-Up //Re: Climbing Kites in Calm CKC

Group: AirborneWindEnergy Message: 5211 From: dave santos Date: 12/27/2011
Subject: Woopy Sparred Ram-Air Inflated Wing

Group: AirborneWindEnergy Message: 5212 From: blturner3 Date: 12/27/2011
Subject: Re: Warren Buffett quotes

Group: AirborneWindEnergy Message: 5213 From: Joe Faust Date: 12/27/2011
Subject: Re: Woopy Sparred Ram-Air Inflated Wing

Group: AirborneWindEnergy Message: 5214 From: Pierre Benhaiem Date: 12/28/2011
Subject: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5215 From: dave santos Date: 12/28/2011
Subject: Re: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5216 From: dave santos Date: 12/28/2011
Subject: Tethered Avation ConOps (TACO) v0.8 (coolIP)

Group: AirborneWindEnergy Message: 5217 From: Joe Faust Date: 12/28/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)

Group: AirborneWindEnergy Message: 5218 From: dave santos Date: 12/28/2011
Subject: Fw: FAA Notification for Airborne Wind Energy Systems (AWES)

Group: AirborneWindEnergy Message: 5219 From: Bob Stuart Date: 12/28/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5220 From: dave santos Date: 12/28/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5221 From: Pierre Benhaiem Date: 12/29/2011
Subject: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5222 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5223 From: Doug Date: 12/29/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)

Group: AirborneWindEnergy Message: 5224 From: Dan Date: 12/29/2011
Subject: kick-start-energy-technologies

Group: AirborneWindEnergy Message: 5225 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5226 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5227 From: dave santos Date: 12/29/2011
Subject: Re: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5228 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5229 From: dave santos Date: 12/29/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)

Group: AirborneWindEnergy Message: 5230 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5231 From: dave santos Date: 12/29/2011
Subject: ARPA-E AWE News on Twitter and Facebook

Group: AirborneWindEnergy Message: 5232 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5233 From: Joe Faust Date: 12/29/2011
Subject: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5234 From: blturner3 Date: 12/29/2011
Subject: Re: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5235 From: dave santos Date: 12/29/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5236 From: blturner3 Date: 12/29/2011
Subject: Re: kick-start-energy-technologies

Group: AirborneWindEnergy Message: 5237 From: Bob Stuart Date: 12/29/2011
Subject: Re: kick-start-energy-technologies

Group: AirborneWindEnergy Message: 5238 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5239 From: dave santos Date: 12/29/2011
Subject: Fw: [AWES] Physics of Rotating AWES Wings (Doug, RobertC; Please for

Group: AirborneWindEnergy Message: 5240 From: Pierre BENHAIEM Date: 12/29/2011
Subject: Re: Rigid or fabric wing?

Group: AirborneWindEnergy Message: 5241 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5242 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^

Group: AirborneWindEnergy Message: 5243 From: Pierre BENHAIEM Date: 12/29/2011
Subject: Re: Offshore submerged water turbine kite driven?

Group: AirborneWindEnergy Message: 5244 From: Bob Stuart Date: 12/29/2011
Subject: Re: Offshore submerged water turbine kite driven?

Group: AirborneWindEnergy Message: 5245 From: Doug Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5246 From: Joe Faust Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5247 From: dave santos Date: 12/30/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;

Group: AirborneWindEnergy Message: 5248 From: Bob Stuart Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5249 From: Bob Stuart Date: 12/30/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;

Group: AirborneWindEnergy Message: 5250 From: Pierre BENHAIEM Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5251 From: Pierre BENHAIEM Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5252 From: Joe Faust Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Group: AirborneWindEnergy Message: 5253 From: dave santos Date: 12/30/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;

Group: AirborneWindEnergy Message: 5254 From: dave santos Date: 12/30/2011
Subject: Re: Basis for Makani R&D Claims?




Group: AirborneWindEnergy Message: 5205 From: Doug Date: 12/27/2011
Subject: Re: Betz' limit, new visits
Joe:
The first silly thing they say is that regular wind turbines get 30% efficiency, when it's commonly known that the best and newest can get almost the full 59%. They call a Standard Horizontal Axis Wind Turbine Rotor a "plane propeller" because it rotates in 2-D plane, ("plane", not "airplane") and it resembles a (airplane) propeller.

confused yet?

Obviously this is a poor choice of terminology, and is our first indicator of how silly what we are reading IS. Their choice of words is worse than anyone could make up! How can their one experiment have a "finding" that so differs from simple data taken in large amounts from working wind farms over decades? Suddenly, in one fell swoop, they have stumbled across ALL historical windfarm data worldwide being overstated by 100%??? Joe do you even READ this stuff before passing it along?

Aaaa-HA!, we read further: this incredible "finding" is easily explained by their equally incredible crackpot theory! See, the fluid curves! Who knew??? :) ALL "Professor Crackpots" talk like this, Joe. It is derigueur. (A "new" theory to explain "new" findings!) Then they conclude that their turbine is more efficient, especially in water. Hey, both are approximated by an incompressible flow, and there's little difference, but at this point in the paragraph, why would anyone still believe ANYTHING they're saying?.

Here's a summary of what is well-known:
1) Windfarm turbines can approach the 59% Betz coefficient efficiency. (Most small wind turbines perform closer to the 30% efficiency range, being simple fixed-pitch machines operating at a lower Reynolds number.)
2) Most windfarms, over time, operate at below a 40% capacity factor (some days there is little or no wind). (capacity factor is different from efficiency)
3) Gorlov rotors are twisted to overcome torque pulsation of a Darrieus blade, that normally pushes in different directions and amounts, at various points of the rotation.
4) Darrieus type rotors, whether Gorlov (twisted) or not, are less efficient than "propeller-type" rotors, using more material to sweep the same area, at higher solidity and lower TSR.

This stuff has been well-known for many years.
:) Doug S.
PS See cut-paste of their summary below:

"The most interesting finding of our analysis is that the maximum efficiency of the plane propeller is about 30 percent for free fluids. This is in a sharp contrast to the 60 percent given by the Betz limit, commonly used now for decades. It is shown that the Betz overestimate results from neglecting the curvature of the fluid streams. We also show that the three-dimensional helical turbine is more efficient than the two-dimensional propeller, at least in water applications. Moreover, well-documented tests have shown that the helical turbine has an efficiency of 35 percent, making it preferable for use in free water currents." Gorban, Gorlov, Silantyev

Group: AirborneWindEnergy Message: 5206 From: Joe Faust Date: 12/27/2011
Subject: News sample re: Makani Power
http://www.technologyreview.in/business/39388/page1/

Two seconds of Google search  by these authors could find over 100 other companies doing AWES R&D. 
Group: AirborneWindEnergy Message: 5207 From: harry valentine Date: 12/27/2011
Subject: Re: Betz' limit, new visits
Doug has raised some interesting and very valid points.

Turbine efficiency changes with flow velocity .  .  .  . reach peak efficiency at high wind velocities .  .  .  . yet another reason to install wind turbines at high elevation above ground. The rhyme goes like this, "the higher the elevation .  .  . the higher the turbine efficiency .  .  . the higher the turbine output!"


Harry



To: AirborneWindEnergy@yahoogroups.com
From: doug@selsam.com
Date: Tue, 27 Dec 2011 15:30:02 +0000
Subject: [AWES] Re: Betz' limit, new visits

 
Joe:
The first silly thing they say is that regular wind turbines get 30% efficiency, when it's commonly known that the best and newest can get almost the full 59%. They call a Standard Horizontal Axis Wind Turbine Rotor a "plane propeller" because it rotates in 2-D plane, ("plane", not "airplane") and it resembles a (airplane) propeller.

confused yet?

Obviously this is a poor choice of terminology, and is our first indicator of how silly what we are reading IS. Their choice of words is worse than anyone could make up! How can their one experiment have a "finding" that so differs from simple data taken in large amounts from working wind farms over decades? Suddenly, in one fell swoop, they have stumbled across ALL historical windfarm data worldwide being overstated by 100%??? Joe do you even READ this stuff before passing it along?

Aaaa-HA!, we read further: this incredible "finding" is easily explained by their equally incredible crackpot theory! See, the fluid curves! Who knew??? :) ALL "Professor Crackpots" talk like this, Joe. It is derigueur. (A "new" theory to explain "new" findings!) Then they conclude that their turbine is more efficient, especially in water. Hey, both are approximated by an incompressible flow, and there's little difference, but at this point in the paragraph, why would anyone still believe ANYTHING they're saying?.

Here's a summary of what is well-known:
1) Windfarm turbines can approach the 59% Betz coefficient efficiency. (Most small wind turbines perform closer to the 30% efficiency range, being simple fixed-pitch machines operating at a lower Reynolds number.)
2) Most windfarms, over time, operate at below a 40% capacity factor (some days there is little or no wind). (capacity factor is different from efficiency)
3) Gorlov rotors are twisted to overcome torque pulsation of a Darrieus blade, that normally pushes in different directions and amounts, at various points of the rotation.
4) Darrieus type rotors, whether Gorlov (twisted) or not, are less efficient than "propeller-type" rotors, using more material to sweep the same area, at higher solidity and lower TSR.

This stuff has been well-known for many years.
:) Doug S.
PS See cut-paste of their summary below:

"The most interesting finding of our analysis is that the maximum efficiency of the plane propeller is about 30 percent for free fluids. This is in a sharp contrast to the 60 percent given by the Betz limit, commonly used now for decades. It is shown that the Betz overestimate results from neglecting the curvature of the fluid streams. We also show that the three-dimensional helical turbine is more efficient than the two-dimensional propeller, at least in water applications. Moreover, well-documented tests have shown that the helical turbine has an efficiency of 35 percent, making it preferable for use in free water currents." Gorban, Gorlov, Silantyev

Group: AirborneWindEnergy Message: 5208 From: Joe Faust Date: 12/27/2011
Subject: Re: Climbing Kites in Calm CKC
Step towing is a cousin to the strategy involved in Climbing-Kite Contest: 

 Henry, 

        I must assume that you visited already all the links on the announcement page. If not yet, such is recommended. 

 
A recent video relating the Climbing Kite Contest is an indoor zerowind pilot operating from staying seated in a chair while operating jerks on the kite line to input energy to the wing and the wing's flight pattern.    The core physics involves taking advantage of high airspeed over the wing during an accelerated pull of the tether, followed by relaxation of the line so the wing stops the kiting principle and enters the gliding principle; actually the kiting principle is never full lost as tether mass still hangs during the glide.  The glide occurs after rapid climb from the pull; the glide is to be away from the center, so that in the next pull there will be more line out for a longer climb cycle.  The cycles are repeated with a net climb of the wing. 

 
Notice that some abbreviation of terms are to managed.   Have "kite" as the combination of wing with tether with resistive cause for tension on tether; thus three parts make up kite: w, t, r.    wing set, tether set, resistive set.   Arm jerks or robot jerks are part of the r set to be operated with timing that lets specially designed wing to kite-deflection climb during pull; the designed wing is to be controlled in one manner or another to enter a turn and glide during tether relaxation, or have a reversing configuration to avoid turn, but just 180 degree reverse of flight: up in jerk, glide oppositely in relaxation.      The window of opportunity resides in get high L/D in the glide and good climb in the kiting phase. 

 
Horvath uses thermals, but he also has shown some true skill in achieving energy input for lengthening tether during cycles of powering and relaxing to glide. 

 
A key video, as you asked:  Play indoor kite on chair----"zen flyer"

 
Best of Lift to you and yours, 
JoeF
Group: AirborneWindEnergy Message: 5209 From: Joe Faust Date: 12/27/2011
Subject: Re: Climbing Kites in Calm CKC
Some matters for AWES on related matters: 

http://ozreport.com/forum/viewtopic.php?t=23414    As interested, see all posts in that thread. 
Step Towing
Group: AirborneWindEnergy Message: 5210 From: dave santos Date: 12/27/2011
Subject: Step-Towing Scale-Up //Re: Climbing Kites in Calm CKC
Once again what we first saw done with toy kites scales up rather painlessly. The HG and PG Step-Towing Revolution proves good AWE working altitudes can be reached by surface winches without a large field, E-VTOL, or lifting gas. This is a critical AWES capability, to be able to launch thru calm (like normal overnight surface inversion) into good wind waiting above.
 
Note that these playful weekend scientists managed to "manlift" (fairly) safely and legally under existing flight regs. 100 dollars and a case of beer would hire such pilots to pull on a generator capstan after the step-tow (to net maybe 10kW avg in a good breeze). One could even charge eager licensed pilots a sport fee, for power cheaper than coal. All glider classes have power-making potential and can be re-purposed as AWES UASs.

Ballistic phases can be envisioned for future CKC, where after a brief tow pulse to accelerate to high speed, the wings go to zero AoA, or even fold, and the aircraft is thrown upward at low drag. The bounding flight of many birds has brief ballistic periods. I recently proposed KULeven spin up its hot kiteplane (concept) short-lined like a sling shot and let it go, paying out its tether freely as it climbs out over 500m high, another "tow-based" CKC idea. The slingshot method eliminates in principle the vestigal step-tow tow-field, but can transition to step-tow for extended climb.
 
coolIP
 
 
Group: AirborneWindEnergy Message: 5211 From: dave santos Date: 12/27/2011
Subject: Woopy Sparred Ram-Air Inflated Wing
Below is an interesting hybrid wing type suitable for "homestead" scale AWES. It recalls the Flexifoil sport kite, which has a fiberglass spar within a parafoil. Resistence to collapse and less bridling are major virtures, for a rough doubling of weight over pure fabric. Its still a real floater, a classic NASA slow foil profile, very docile. The wing by itself could cost as low as ~800USD in high production. The second link has a good set-up and fly video-
  1. EAA - Light Plane World - Woopy Can Fly


  2. www.eaa.org/lightplaneworld/articles/1005_whoopy.aspCached - Similar

  3. The Woopy-Fly weight-shift wing has a single aluminum and carbon fiber spar which gives strength to the inflated fabric structure. It folds for storage like a ...
  4. [PDF]
  5. Woopy-Fly Inflatable Wing Ultralight Aircraft

    www.avweb.com/.../WoopyFly_InflatableWingUltralight_202563-1...Cached - Similar
    Block all www.avweb.com results
    May 16, 2010 – The Woopy-Fly, a sort of paraglider/trike/ultralight hybrid shown on the world stage at AERO Friedrichshafen this April 2010 in Germany, has a ...
Group: AirborneWindEnergy Message: 5212 From: blturner3 Date: 12/27/2011
Subject: Re: Warren Buffett quotes
It was probably inappropriate of me to bring up capitalism in a technical forum. I was just disappointed that the FAA's totalitarian/socialist regulation methods have failed to bring forth the fruitful skies of my imagination. Maybe these skies are impossible and the FAA has nothing to do with it. But in my mind, as profound as aviation's impact has been, it is still far short of what it could be.

Brian

Group: AirborneWindEnergy Message: 5213 From: Joe Faust Date: 12/27/2011
Subject: Re: Woopy Sparred Ram-Air Inflated Wing
Group: AirborneWindEnergy Message: 5214 From: Pierre Benhaiem Date: 12/28/2011
Subject: Rigid or fabric wing?

Here a rough study from available rigid and fabric hang gliders.

Caractéristiques Technique - swift light d'aériane en France: planeur ...

Tarifs - swift light d'aériane en France: planeur rigide décollable à ...  (about 25000 $; 12.5 m², 48 kg; about 520 $/kg; about 2000 $/m²)

Parapente.pro : Fun 42 MK2 (Apco / 2011.00 / apcotandem) (about 4900 $; 8.7 kg; about 563 $/kg; about 116 $/m²,best ratio L/D is about 8 or 8.5).Note: for a ram kite the price is two times lower:280 $/kg and 60 $/m²,but for a lesser ratio L/D.

Swift as power kite/m² would be about 6 times Apco (In fact a lesser value because of tether drag).So a 12.5 m² Swift roughly = 1.5 Apco .

In one hand 25000 $ for rigid wing (Swift); and 7350 $ for fabric wing (Apco).

If the duration of rigid wing is more than 3 times (taking account of resistance but also the probability of destruction by crash) the duration of fabric wing it can be preferred for some uses.

PierreB

Group: AirborneWindEnergy Message: 5215 From: dave santos Date: 12/28/2011
Subject: Re: Rigid or fabric wing?
Pierre,
 
This is a very complicated subject due to the complex nature of kite-flight. Some key factors can include-
 
-power to weight/ span-loading (soft wing wins)
-stall speed/ landing speed (soft wing wins)
-sink rate (soft wing usually wins)
-maintenance/ repair (soft wing wins)
-crash safety/ liability and hull insurance (soft wing wins)
-mega-scalability (soft wing wins)
 
Also note that sport parafoils of good quality, like Pansh Kites, which are not rated for human flight, are far cheaper still, <500USD for a 12m model. Small AWESs do not need a human-rated wing. So then you get nearly 50 times cheaper for a decent soft wing over a high quality rigid wing.
 
Bet on cheap soft wings to dominate at first, and maybe rigid wings later. Hybrid wings, or mixes of sort and rigid in hybrid systems, may be the best of all.
 
All wings are still mostly handmade. Wing production automation (Wayne German's early concern) may be the key winning factor,
 
daveS

 
  
Group: AirborneWindEnergy Message: 5216 From: dave santos Date: 12/28/2011
Subject: Tethered Avation ConOps (TACO) v0.8 (coolIP)
This is still more like a mass of loose notes than a polished work, but
a comprehensive potentially consensual picture is forming.
 
The next step is to integrate the latest FAA Circular request topics.
 
Please forward your input, for a 1.0 version to be submitted on the
Federal docket in Feb-
 
===========================================
 
8TH DRAFT

Tethered-Aviation Concept of Operations (TACO)
Case Focus on Experimental Airborne Wind Energy Systems (AWES)

Acronyms

AKA AmericanKitersAssociation
AOPA AirplaneOwners&PilotsAssociation
ALPA AirLinePilotsAssociation
AMA AmericanModelersAssociation
ARPA-E AdvancedResearchProjectsAgency(Energy)
AWE AirborneWind Energy
AWES AirborneWindEnergySystem
AWEC AirborneWindEnergyConsortium
AWECS AirborneWindEnergyConversionSystem (old usage)
AWEIA AirborneWindEnergyIndustryAssociation
AWEA AmericanWindEnergyAssociation
CAT ClearAirTrubulence
ConOps Concept of Operations
DOE DepartmentOfEnergy
EAA ExperimentalAircraftAssociation
E-Flight ElectricFlight
ETOPS ExtendedOperations
EndurOps EnduranceOperations
FF FreeFlight XC
FAA US FederalAviationAdministration
FARs US FederalAviationRegulations
FBO FixedBaseOperator, a small airport admin
FEG FlyingElectricalGenerator
FSDO FlightStandardsDistrictOffice
HAWP HighAltitudeWindPower
ICAO InternationalCivilAviationOrganization
LSA LightSportAviation/Aircraft Category
LLJ LowLevelJet Stream
METAR METeorologicalAviationReporting data format
NAS NationalAirApace
NASA NationalAeronautics&SpaceAgency
NextGen NextGeneration aviation plan/standards
NOTAM Notice(s)ToAirMen
NIMBY NotInMyBackYard population interests
PIC PilotInCommand
PIREP PilotReport(s)
PIC PilotInCommand
RAD RapidAWEDevelopment
R&D Reasearch&Development
SARPs ICAO Standards&RecommendedPractices
TA TetheredAviation
TACO TetheredAviationConOps
UAS UnmannedAircraftSystem
sUAS smallUAS
UAV UnmannedAerialVehicle
VO Visual Observer
XC CrossCountryFlight


Preface to this Draft

In 2010 FAA and NASA staffers informally called on the early AWES industry
to define its new "energy aircraft" types into the FAA's Category/Class system
and develop a ConOps for AWES in US NAS. In response, AWEIA undertook
this document, TACO, to formally address these requirements. The work aims
toward a consensus FAA Advisory Circular and ICAO Proposal-For-Action, 
informing aviation stakeholders about AWE issues and operations. TACO covers
the full scope of TA, not just AWES, building on solid existing models wherever
possible, and is intended to merge smoothly with NextGen Airspace ConOps.
This is an open living document; AWEIA member, KiteLab Group, builds and
maintains it on a volunteer basis. Send corrections, additions, & comments to:
 
 
CONTENTS
 
Executive Summary
Aviation Self-Regulation Principle
Regulatory Standards, Exceptions, and Exemptions
FAA AWES Temporary Rules
FARs Category, Class, & Type Certifications for TA
Pilot Categories & Training
Operational Categories
 

Executive Summary

Tethered Aviation is an aeronautical class and set of methods to transfer
force over distance via cables between aircraft, payloads, and anchors or vehicles.
Well-known instances include kites, aerotowing, and aerostats (moored balloons).
New tethered flight concepts are expanding aviation capabilities to create new
applications, jobs, industries and novel recreations. TA even promises to generate
abundant wind energy, as AWES, also known as "Kite Energy".
This clean energy technology may someday subsidize, by airspace usage
fees and excise taxes, the needs and dreams of populations and general aviation.
Stakeholders such as pilots, developers, regulatory bodies, and government are
working together to resolve technical and social challenges. The current aviation
regulatory framework is not broken, but daily protects public saftey at reasonable
cost, and is a sound foundation to build on.
 
Pilots are primary workers in airspace most exposed to flight risk, and the FAA
itself is pilot-led. The standing FAA requirement for direct pilot supervision of
UAS systems will hold for years yet. This ConOps is thus "pilot-centric",
embracing the pilot as a key stakeholder, but also forward-looking to eventual
validated autonomous flight. Upholding aviation norms and traditions, pilots 
already lead R&D of safe effective TA and will ensure safe operations in
shared airspace. New pilots will be needed to fill the many flying jobs created.
 
The aerospace industry will create large-scale systems that pilots accept and
FAA inspectors certify as airworthy. Policy developers and decision makers,
from the national to local scale, are a key stakeholder group to properly inform. 
Knowledgable stakeholders must strive to honestly convince extended stakeholders
(populations) that TA enhances society as a "good neighbor". TACO best-practice
standards lay the basis for wide public acceptance. 
 

Aviation Self-Regulation Principle

The FAA relies on all aviation sectors, via user agencies, associations, and
industries, to help define, promote, and even enforce best practice of members.
Safe aviation operations presided over by responsible sector self-government
allows the FAA to maximize its limited resources and regulate with a light
touch. Failure of any sector to ensure safety brings down the full weight of
FAA enforcement.
Accordingly, the Airborne Wind Energy Industry Association (AWEIA)
has, as part of its formal mission. a global leadership role in self-regulation
of AWE and related TA. TACO is AWEIA's project to coordinate Consencus
Standards for safety and to act as industry liason with regulators like the FAA
and ICAO. AWEIA intends to enforce on its members the highest safety 
standards in its field, even exceeding and anticipating government regulations.
 
AWEIA will petition the FAA for new Rulemaking as needed, following
the successful example of the Experimental Aircraft Association and
FAA together creating a regulatory framework for the new LSA category.
AWEIA will work within the ICAO framework to develop a core SARPs. 
There are already urgent R&D safety issues AWEIA is addressing, such as
obligatory sharing of safety-critical failure modes & mishap reporting.
AWEIA is just one of several associations with overlapping interest in TA.
 
TA operators will emerge from enthusiast communities: EAA and AOPA have
strong interest in the new sectors. The AKA recreational & professional kite
operations. The AMA is responsible for safe hobbyist aviation. User associations
in soaring and other sectors that routinely perform tethered operations
have unique stakeholder roles. Wind energy industry standards promoted by
AWEA also apply to AWE operations. Local government and poulations will
have a strong voice in shaping AWES, with a NIMBY veto power if imapacts
warrant. AWEIA undertakes to reconcile all the stakeholders.


Regulatory Standards, Exceptions, and Exemptions 

These sections present specific concensus standards for regulating TA. Some
of it is legacy FAA "boiler-plate" in process of being adaptation into an
Applicable Standard; an operational manufacturing/design/maintenance/quality
standard, method, technique, or practice approved by or acceptable to a civil
aviation authority. An Exception is a case in which a rule, general principle,
etc., does not apply. There are very few justifyable exceptions to apply to TA. An
Exemption is approval to be free from current regulations in 14 CFR. Minimal
need for any exemption of TA from FARs is a TACO priority.
 
 
FAA AWES Temporary Rules
 
Following a large build-up in interest and activity, late in 2011, the FAA released 
temporary policies governing experimental AWES operations. An AWES community
discussion followed and concensus standards were drafted around many key issues.
 
The "case-by-case" review process was seen as a reasonable standard for
early AWES R&D regulation. Mishap reporting and open Failure-Mode disclosure
by developers was expresses as an essential community need.
 
Standards for flight parameters, such as altitude, conspicuity, VFR conditions are
explicitly in force by the 2011 FAA circular. Existing airworthyness standards based
on aircraft mass and velocity are additionally proposed for enforcement by AWEIA,
with its members on notice.
 
The FAA Advisory Circular governing Obstruction Marking and Lighting 
AC 70 7460 1K was accepted as the default standard for AWES conspicuity.
 
New FAA standards for sUAS operations cover key issues common
to AWES. A PIC and VO, with sense-and avoid cabability are particular
priorities to adopt as an AWES standard for those systems with
high-consequence risk.
 
Multi-tethers are proposed as a basic safety redundancy method, and the
determination of airworthness should account for the lack or presence of
multi-tethers, or equivalent measures, in the AWES design.


FARs Category, Class, & Type Certifications for TA
 
Existing FARs cover most of the engineering and flight standards
required to properly regulate the new aviation types.  FARs can be
vague, confused, and contradictory; the classification scheme is a
historical patchwork. The system allows needed wiggle-room, with
exceptions, exemptions, and options at the discretion of FAA field
authorities. NextGen FARs will overhaul classification, but quirks
will surely persist. 

A logical step toward proper regulation is to finally define tethered wings
(large kites) as aircraft. Currently only airplanes, rotorcraft, gliders, and
balloons are formally recognized as Aircraft. A tethered wing anchored
in wind and/or associated motor-winch can be classed as an Engine,
rated by power, for motive or output power. Ratings and Operating
Limitations would be certificated just as reciprocating and rotary IC
engines are. The notion of an Airframe remains the same, with the tether
structural interface an added technical concern. Exotic new kinds of
tethered aircraft will need to be Type Certified in a suitable new Category
or special Classes.

Most of the profusion of potential TA design Types pre-sorted into the
FAA's Aircraft/Airman/Operations Category, Class, & Type System.
Categories naturally grow by adding Classes. Specific TA Classes are
proposed to suppliment current Categories. A new TA Category might
emerge and be ordered in detail under the LSA model of classes and sets.
 
Like any other aircraft, TA platforms should be classified by gross-weight
and airspeed, by the same physics of  safety-critical "consequence". Weight
and Speed (mass & velocity) are primary determinants of Class within a
Category. In general higher mass/velocity Classes have Higher Consequence
Failure-Modes requiring proportionally higher standards for equivalent safety
(mortality to flight hours). 

Current classifications include: normal, utility, acrobatic, commuter, transport,
manned free balloon, glider, special, restricted, etc. As an example of how a TA
Class can apply across Categories, some given Types are potentially suitable or
routinely modified for aerotowing, with special appilicable standards.

Single/Multi-Engine Classes- Many TA applications have powered modes that
naturally assign them to an Engine Class within a Category. The trade-off of 
improved reliability from multi engines is the higher required standard of
Pilot training & aircraft engineering. 

With respect to Certification of aircraft under the FARs, Class means a broad
grouping of aircraft having similar characteristics of propulsion, flight,
or landing. Examples include: airplane; rotorcraft; glider; balloon; landplane;
and seaplane.
 
Structural systems used for airframes also fundamentally categorise aircraft. A 
fabric "softwing" has very specific different design and operational parameters
compared to any high speed rigid wing. Best practice is sought in the closest
related avaition specialties, and regulated to those standards, as the ready default.
 
New sub-classes are proposed for major new configurations like free-flight and 
cross-linked flying formations. Experimental and rare aircraft types are flexibly 
integrated by ad-hoc classification into multiple categories & classes. Aviation is
increasingly diverse and a major new branch could merit a wholly new Category.
 
Any conventional aircraft can in principle be put on a tether, which
does not negate its status as a legal aircraft of a given mass & speed
envelope, but adding a tether adds operational complexity and hazard.

Provisional Sub-Classes- Tethered-Aerobatic, Tethered-Single-Engine
(or turbine), Tethered-Multi-Engine (or turbine), Tethered-Normal, Utility,
Sport, Ultralight, Moored-Balloon, Aero-Towed Glider, Tethered Rotorcraft.

Categories and Classes of aircraft & operations mix, overlap, or otherwise 
interrelate. For example, a specific type can be operated as either a
Commercial or Private Aircraft, with different FARs in play.

Small Aircraft- 12,500 pounds or less, maximum certificated takeoff
weight. This is a default "line-in-the-sand" for developers and regulators
as AWES grow larger, with advantages to staying just small enough.

AWES that operate aerobatically & incur high G-loadings are Acrobatic
Category (limited to 12,500lbs gross). Tether-Weight is to be counted
toward rated gross weight. Tether-Drag should count against rated
L/D. Autonomous Flight of high-consequence platforms (high mass &/or
velocity, especially around populations) require a proportionately more
cautious rigorous path to validation and certification.

AWES are generally high-duty UAS, meriting special Utility designation.
According to gross weight they can be sorted into Ultralight, Sport,
Normal, Commuter, & Transport Weight & Airspeed Categories.

Operational altitude is a major category criteria. Some relevant ceilings-
400ft for low mass low speed hobbyist model aviation. 500ft as a "floor"
for general VFR aviation. Class G airspace is low altitude and variable,
with higher ceilings in remote areas, 2000ft obstruction limits rule
mast and tower certification, 18,000ft is the defined ceiling to avoid
transport aviation operations. 25,000ft is the defined theshold of
High-Altitude flight, with special applicable standards.
 
Stall Speed is a key aircraft safety parameter, the lower the better, with the
widest possible range of operation desirable between max airspeed & stall
speed. Fixed-Wing AWES that land at a fixed point face a challenge to
not operate too close to stall on final approach, or land too hard. Sink Rate
or Terminal Velocity might be a partial basis for some AWES regulatory
categorization.
 

Pilot Categories & Training

Pilot training and testing is fundamental to aviation. Conventional
pilots in AWES-shared airspace need awareness of new operations and
conditions. Many AWES commercial venture starts lack formal aviation
backgrounds and face acculturation along FAA approved paths. AWES
pilots must master basic aeronautics, plus specialized knowledge and
operational proficiency. As high-consequence risk emerges by powerful
industrial-scale systems, AWES crews must ultimately meet equivalent
standards of certification to Transport Pilots. See Sec. 61.31 Type rating
requirements, additional training, and authorization requirements.
 
As used with respect to the certification, ratings, privileges, and limitations of
airmen, Class means a classification of aircraft within a category having similar
operating characteristics. Examples include: single engine; multiengine; land;
water; gyroplane; helicopter; airship; and free balloon; New classes of airman
are proposed for new TO types that do not clearly fall into existing classes. 
 
Mature TA pilot standards exist within towed gliding (including hang
gliders and paragliders), banner towing, and many approved niche
aviation systems.

TA Operational Categories/Classes 

Flight operations vary within pilot and aircraft categories. Conditions
and appications often impose specific critical constraints. New multi-modal
AWES systems blend operational feaures of usually discrete models, for
example, just as a glider moors or unmoors in and out of free-mode.
 
Altitude- Obstuction Reg altitude ( increase in operational complexity,
by added redundancy, can actually enhance safety. 
 
Large- Categories- Transport, Normal, Utility, Acrobatic, Limited,
Restricted, and Provisional. Provisional uses are defined as needed- STOL,
High Altitude, Marine Environment, Unmanned, IFR, Weight & Speed Cats.,
Obstruction, & so on.
 
Acrobatic Class- Aerobatic operation is a feature of some AWES, with
issues of conpsicuity, high cycle structural loadings and fast controls.
 
 
Novel TA/AWES Categories, Classes, Sets, and Types
 
The explosion of new configurations defies final classification, but can
be described generally.
 
AWES with Surface Based Electrical Generation
 
Many AWES schemes seek to minimise mass aloft by keeping electrical
generation and conductors at the surface. The purest expression of this
philosophy is "rag and string only", with many potential advantages
to aviation safety and economics. Ground-based actuators (winches) can
be massive industrial grade machinery, without the delicate margins of
flyable servos. Radar clutter, comm link dependence, inspectability, high
mass-velocity, and many other issues are mitigated. There will still be
enormous challenges to safe operations as mechanical power scales grow.
 
AWES with Electrical Power Systems Aloft

Electrically Conductive AWES Tethers and generators require added
standards to address inherent safety issues. A general suggestion is to
maintain terrestrial electrical code and fire safety standards as a default
baseline, with aviation standards overlaid.
E-Flight is a fast progressing new category of general aviation. Tethered
E-Flight will share many of the existing and pending standards. E-VTOL
will inherit key standards of existing VTOL.
 
Case Note: Sky WindPower, Inc, is well regarded for its study of the
electric quadcopter AWES concept space. Makani Power, Inc, leads in 
developing large advanced composite autonomous aerobatic E-VTOL
AWES. The Makani models are useful benchmarks for regulation study,
with data being generated via a DOE contract.
 
 
Autonomous AWES
Autonomous Flight is slowly maturing as an aviation option. Many teams
are working to automate AWES flight operations to avoid human piloting.
Tethered autonomy has both favorable and adverse aspects. Tether physics
can constrain or add chaos. Flight software must be created to "cleanroom"
standards and formally validated. Sensory and situational uncertainy are
presistent problems. Exception handling is a critical challenge. Decision to
relaunch a system after an automatic shutdown is a "tough call" to automate.
Meanwhile, human piloting will rely as necessary on existing avionics, and
supervised autopiloting generally.
 
 
Cellular Aerial Arrays

Formations of TA aircraft joined by tethers into dense-arrays is a major AWES
configuration class. A goal of dense-array methods is to greatly enhance general
aviation safety and reliability by avoiding airspace (and land) sprawl for an
equivalent power capacity. Many functional units can be aggregated to fly as
one well-integrated flight control process, as opposed to many independently
(auto)piloted units.
 
Arrays can incorporate any of the many classes of AWES units. The array can
constrain its units into a high "aggregated stability" whereby the momentary
instabily of any single unit is cancelled by the normal action of its neighbors.
 
High Conspicuity and redundant surface connections are safety advantages,
but given a large arrays, an unlikely worst-case mishap of a dragging breakaway 
could be catastrophic. The highest professionalism and redundant levels of
"killability" are required.
 
In the long-term, megascale cellular aerial arrays are a megascale geo-engineering
technology with a vast potential impact. Case Note: TUDelft and KiteLab Group are
the R&D leaders in the design-space of cross-linked formations of AWES units.
 
 
High Altitude Kite Flight
 
Even a century ago, kites where shown capable of reaching altitudes in excess
of 30,000ft. Current art and short-term economics favor low-altitude AWE.
Nervertheless, a new round of high-altitude kite aeronautics is is poised
to explore "fuelless aviation" applications even to around 100,000ft. These will
be demanding experiments conducted by top aerospace teams as approved by
the FAA on a case by case basis.
 
Currently, the stretching of tethers to high altitudes is an unacceptable hazard to
all classes of aviation in shared airspace. The consequences of breakway and
runaway are aggravated. Persistent high Altitude TA must remain in restricted
airspace and await NextGen capabilities to expand operations.
 
Existing missle ranges are proposed as an ideal venue for high-altitude TA testing
on a time-shared basis, as most such restricted airspace is not intensively needed
for rocketry.
 
 
"Free Flight"- Wind Powered Avaition
 
Free-Flight is a frontier of aviaton based on two or more wings tethered together.
Its been shown with small models that if each wing flys in its own wind, the tether
stretched across a wind gradient, they can work in opposition and sustain flight in
any direction. Unlike traditional soaring dependent on thermals or terrain, Free-Flight
can be sustained ordinary surface wind gradient or any sort of wind shear, like around 
LLJs and inversions.
 
Case Note: National champion glider pilot and aeroengineer, Dale Kramer, proposes
a cross country demonstration of Free-Flight by tethering his high performance
glider to a large kite farther above. By working glider against kite its predicted he can
fly almost indefinitely without fuel. The FAA traditionally accomodates such unique
aviation feats that advance aeronautical knowledge on a case-by-case basis, with only
the highest level of skill and expertise allowed. There will be many unique aeronautical
feats to attempt along these lines.
 
 
Tethered Rotorcraft
 
Many prototype and proposed tethered rotorcraft are proposed for AWES. Some
are E-helicopters whose motors also generate and others autogyros modulated to pull
against loads. General rotorcraft design and.operational factors as currently defined
will apply to the new rotorcraft, with tether factors as added concerns.

 
AeroTowing, Banner Towing
 
Traditional TO will persist under existing FARs. A constant exchange of technology
will occur with new types of TO, and many of the old rules will still apply.
 
Aerotowing continues as a major method of launching gliders and as a design option
for certain situations. An active world record category involoves towing as many
gliders as possible from one tow-plane. Utility towing of cargo and passengers
might make a comeback in the future due to economic or practical considerations.
 
Traditional banner towing operations continue to evolve by incremental hardware
and operational improvements. New types are emerging; for example, the lifitng
of mega-flags by helicopter.
 
 
Aerostats
 
The term Aerostat was first associated with Moored Balloons, but logically extends
to persistent tethered electric aircraft or kite flight. Persistent E-Flight is practical 
by means of a conductive tether. Kites can keep station in calm by towing in circles
from vehicles or by phased tugs from fixed winch networks.
 
 
Moored Balloons
 
Once common as wartime Barrage Balloons, Moored Balloons are making a
comeback as radar stations (to 18000AGL) and for low-altitude advertizing.
Many AWES designs employ Moored Balloons for peristence aloft. Moored
balloon regulations are mature and may represent an early regulatory approval
path for AWES.
 

Current TA Norms & Regulations

Key Title 14 Sections of the Code of US Federal Regulations
(Aeronautics & Space) apply to TA. Part 101 contain the seeds
of many TA regs to come, but are due for additions and upgrades to
cover holes in safety and to permit enhanced capabilities. Requiring
certificated airworthiness within current regs will prevent AWES
R&D from creating a "menace-to-aviation".
 
It is widely proposed by the FAA that early AWES might operate under
Obstruction Regs such as govern Antenna Farms, but this model is partial.
For example, an antenna-farm Obstruction is also regulated under mast &
tower structural and electrical codes outside the purview of the FAA. Towers
lack many inherent hazards related to aircraft airworthiness & a potential to
crash far afield (runaway). An AWECS is not a tower & needs to comply
with Airworthiness Standards.
Class G Airspace is a primary realm of current AWES R&D. FSDOs are 
the arbiters of allowable experiments, with good decentralized flexibility.
AWE R&D can shop around for a "best-fit" FSDO (generally remote
low-traffic NAS regions). The Special Airworthiness Certificate in the
Experimental Category is the certification currently available to civil
operators of UAS. NOTAM & COAs allow pioneering AWE R & D to
occur.  Obstruction regs, such as apply to antenna farms, can partly serve
for persistent "static" TA operations under 2000ft AGL. Shielded operations
is an option for an AWES operator at suitable sites. 

Draft FAA s UAS regs call for Pilot-in-Command & Visual Observer crews. A
misconception in the AWE field is that autonomous operations will be permissible
in a short time-frame of a year or two. The safer bet is that many years must pass
before the required safety and reliability is validated and permitted.   

Note: Part 101 sections below edited for brevity, Existing Kite, Moored Balloon,
and Unmanned Free Balloon Regs are partial models for Tethered Free-Flight

PART 101 - MOORED BALLOONS, KITES, UNMANNED ROCKETS
AND UNMANNED FREE BALLOONS
 
Prt 101 applies to any kite that weighs more than 5 pounds intended to be
flown at the end of a rope or cable...including a gyroglider attached to a
vehicle on the surface of the earth is considered to be a kite. No person may
conduct operations that require a deviation from this part except under a
certificate of waiver. No person may operate a moored balloon, kite,... in a
prohibited or restricted area unless he has permission from the using or
controlling agency, as appropriate.
 
101.7 covers "Hazardous operations" and has a key catch-all clause- 
"No person may operate any moored balloon, kite,... in a manner that creates
a hazard to other persons, or their property." It goes on to assert "No person
operating any moored balloon, kite,... may allow an object to be dropped
therefrom, if such action creates a hazard to other persons or their property."
The next subparts apply to the operation of moored balloons and kites.A person
operating a moored balloon or kite within a restricted area must comply only
with 101.19 and with additionallimitations imposed by the using or controlling
agency, as appropriate.
101.13 Operating limitations. (a) Except as provided in paragraph (b) next, no
person may operate a moored balloon or kite- (1) Less than 500 feet from cloud
base; (2) More than 500 feet above the surface of the earth; (3) From an area
where the ground visibility is less than three miles; or (4) Within five miles of the
boundary of any airport. (b) Paragraph (a) of this section does not apply to the
operation of a balloon or kite below the top of any structure and within 250 feet
of it, if that shielded operation does not obscure any lighting on the structure.
 
101.15 Notice requirements. No person may operate an unshielded moored balloon
or kite more than150 feet above the surface of the earth unless, at least 24 hours
before beginning the operation, he gives the following information to the FAA ATC
facility that is nearest to the place of intended operation: (a) The names and addresses
of the owners and operators. (b) The size of the balloon or the size and weight of the
kite. (c) The location of the operation. (d) The height above the surface of the earth at
which the balloon or kite is to be operated. (e) The date, time, and duration of the
operation.
101.17 Lighting and marking requirements. (a) No person may operate a moored balloon
or kite, between sunset and sunrise unless the balloon or kite, and its mooring lines, are
lighted so as to give a visual warning equal to that required for obstructions to air
navigation in the FAA publication "Obstruction Marking and Lighting" . (b) No person
may operate a moored balloon or kite between sunrise and sunset unless its mooring lines
have colored pennants or streamers attached at not more than 50 foot intervals beginning
at 150 feet above the surface of the earth and visible for at least one mile.
 
101.19 Rapid deflation device. No person may operate a moored balloon unless it has
a device that will automatically and rapidly deflate the balloon if it escapes from
its moorings. If the device does not function properly, the operator shall immediately
notify the nearest ATC facility of the location and time of the escape and the estimated
flight path of the balloon. 

Subpart D - Unmanned Free Balloons 101.31 Applicability. This subpart applies
to the operation of unmanned free balloons. However, a person operating an
unmanned free balloon within a restricted area must comply only with 101.33 (d) and
(e) and with any additional limitations that are imposed by the using or controlling
agency, as appropriate. 101.33 Operating limitations. No person may operate an
unmanned free balloon- (a) Unless otherwise authorized by ATC, in a control zone
below 2,000 feet above the surface, or in an airport traffic area; (b) At any altitude
where there are clouds or obscuring phenomena of more than five-tenths coverage;
(c) At any altitude below 60,000 feet standard pressure altitude where the horizontal
visibility is less than five miles; (d) During the first 1,000 feet of ascent, over a
congested area of a city, town, or settlement or an open-air assembly of persons
not associated with the operation; or (e) In such a manner that impact of the balloon,
or part thereof including its payload, with the surface creates a hazard to persons or
property not associated with the operation. (a) No person may operate an unmanned
free balloon unless- (1) It is equipped with at least two payload cut-down systems or
devices that operate independently of each other; (2) At least two methods, systems,
devices, or combinations thereof, that function independently of each other, are
employed for terminating the flight of the balloon envelope; and (3) The balloon
envelope is equipped with a radar reflective device(s) or material that will present
an echo to surface radar operating in the 200 MHz to 2700 MHz frequency range.
The operator shall activate the appropriate devices required by paragraphs
(a) (1) and (2) of this section when weather conditions are less than those prescribed
for operation under this subpart, or if a malfunction or any other reason makes
the further operation hazardous to other air traffic or to persons and property on th

(Message over 64 KB, truncated)
Group: AirborneWindEnergy Message: 5217 From: Joe Faust Date: 12/28/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)
[[THE TRUNCATED PART FOLLOWS]]
=============================================
A proposed method is to radar detect airtraffic and only then activate mast and 
tower warning signals. Another idea is to create clear migration corridors,
well chosen gaps in the wind farm pattern, for birds to follow. The design of an
AWECS can range from benign to deadly to birds. Where bird issues are most
sensitive, the slower, softer, more visible systems are favored. Although direct
data is scant, its probable that fast moving kiteplanes flying aerobatically 
constitute the same sort of hazard to birds as large conventional turbines. 
Many birds seem to have a hard time detecting or understanding the threat of a 
large fast-moving object on a highly curved trajectory, but do better avoiding 
an aircraft on a set course. Birds easily see and avoid large slow moving 
tethers and kites, with no known mortality factor. Birds often do not see the 
fine lines on toy kites and collide with them, usually with no bad effect, 
although a small potential for injury exists. Classic kiting is bird friendly, 
with the exception of fighter kites with cutting line. Some South Asian 
traditions even regulate the kite-fighting season based on bird presence.
 
Fallen line must always be collected to avoid snaring wildlife. The risks are
two-way. A bird strike can bring down almost any airplane by varied damage.
Engines can be damaged enough to stop. Control surfaces, windscreens, pitot
tubes, antennas, radardomes, etc. can be made inoperable. A kiteplane is
subject to bird-strike risk, it can be blinded, brought down or breakaway,
creating risk off-field. 
  
Bird study is a part of AWE site assessment. Baseline bird presence should be
determined before a kite farm is established and bird presence tracked for
ongoing impact detection and mitigation. Qualified independent biologists
should be relied on to develop flexible management plans to meet high standards.  
In conclusion, AWE and birds can seemingly coexist well, but its up to designers
and operators to make sure adverse impacts are minimal. 
 
*Bats are presumed to resemble birds in 
their general relation to AWE, but with a more nocturnal presence.

HazMat
 
Improper AWES design and construction, and ongoing operations like airframe
washing, can pollute; such adverse impacts should be prevented. A crash of a
complex modern aircraft system can leave a large debris field requiring
a meticulous clean-up to appropriate environmental standards. Ablation of fabric
particles from aloft may be an issue with poorly formulated kite materials in
high-duty service.

 
TACO/Nextgen Transformation Path  
Iterative-spiral process toward NextGen Integration-

Input from all TA stakeholders and review by NextGen planners.
 
Accommodation of major concerns.  
Technical Validation by Field-Testing.  
Sign-off by stakeholders.  
Adoption into NextGen ConOps.
 
  
Stakeholder Groups

EAA & AOPA are key pilot stakeholder representation. ALPA & Carriers are
not direct stakeholders. as commercial aviation has its own reserved airspace
and will stay well-separated until NextGen standards apply.
 
Local governments, where TA operations impact, are key stakeholder representation
to proactively include in planning.


Forward-Looking TACO:  

TACO focuses mostly on near-to-mid-term AWE R & D. The forward-looking
capabilities referenced below derive from the NGATS Vision Briefing of 2005
toward the NextGen Airspace CONOPS for 2025. Mature Tethered Aviation
Operations (TAO) shall conform to these standards-

NextGen Network Integration- Positioning, Navigation, Timing (PNT) Services;
RealTime Community Of Interest (COI) utility; Layered Adaptive Security (LAS)-
TAO will be a fully integrated sector. PIC comm linked.
 
Service Performance-Based Operations

Load On-Demand; it will be the goal of the AWECS to respond to load demand with 
LAS. Weather-Based Decision-Making- An Essential TAO 
function.
 
Trajectory-Based Operations (TBO)- Variable geometry kitefarm operations 
will be certified. 
Super-Density Operations (SDO)- Airspace will be treated as a limited resource
best maximized by AWE SDO well separated from air traffic.

Autonomous Flight   
Supervisory Override of Semi-Automated Flight is a bridge technology  
NextGen's Moving Constrained Airspace is a capability needed for Tethered
Free-Flight development  EVFR rules for relaxed visibility will widen the
TA flight envelope & be a bridge to Autonomous IFR. 
 
NASA-FAA Research Transition Teams - JPDO Presentation
    
Case Note- Small Airports Hoping to Accomodate AWE R&D    

A persistent myth in popular AWES reportage is that existing aviation norms and 
interests impede progress. Its a reasonable sounding theory, and 
restrictive standards do apply in congested airspace, pending NextGen air traffic 
control, but such airspace is only a tiny fraction of world airspace, even in 
aviation intensive regions. In fact, existing small 
aviation operations are lining up to embrace TA adoption and help perfect it. 
A growing list of small airports willing to host AWE R&D, as a new 
aviation niche market. Due to corporate NDAs , which small airports are already 
developing programs, but face-to-face meetings with airport administrators and 
their stakeholders (aviators, aero clubs, skydivers, etc.) confirm an early 
consensus that AWE can coexist with general aviation, that the operational issues 
are manageable . The stakeholders are eager to validate new multi -use aviation. 

A common profile is a struggling airfield with good winds and low air 
traffic. Administrators informed about AWE aviation and the specific means to 
integrate it safely into existing operations get excited at the possibilities. A 
cautious step-by-step plan is appropriate. Usage fees and partnership agreements 
are a revenue basis. There will be plenty of eager FBOs (Fixed Base 
Operators (of small airfields). 

Many airports have large open spaces around 
runways and away from approaches suitable for limited low altitude
 "killable" AWES arrays under the control of the airport administration. 

Airports with a crosswind runway have an interesting potential to host 
crosswind AWE generator vehicles on the idle runway. Two orthogonal paved 
runways can do the job of adapting to wind direction almost as well as a far 
more expensive paved field open in all directions. Conductive contact strips can 
be embedded along the runway to tap energy for the grid. There is an invisble
airfield traffic pattern to keep clear of. In an emergency, the whole airspace
needs to be clear. Shared airspace around an airport depends 
on all aircraft being able to "sense and avoid". Suggested consencus safety
standards for AWE operations at an airport- Only 
small-scale low-mass low-velocity low-altitude AWE operations are currently 
suited to existing low traffic small airport operations. Dynamic AWE power 
loads and surges must be buffered or isloated from airport systems.  
Aeronautic engineers should perform or advise the AWES design and
help present it for regional FAA FSDO review and approval. Shop around
for NAS regions with air low traffic and willing inspectors.  
Particular concern must be paid to not crowding airfield approaches and
the standard traffic pattern. Current FAA kite visibility standards are weak
and should be exceeded.  
AWECS operations must have a Pilot In Command (PIC) (plus often a Visual
Observer (VO)) able to quickly douse the kites (kite-killers) at first sign of
trouble, especially in case of another aircraft's landing or take-off emergency
(FAA Sense and Avoid requirement). The PIC or VO must monitor radio traffic.  
NOTAM must be daily filed (or equivalent airman awareness, like charted
obstructions), just as skydiving and hot-air balloon operations do. Shared
operations require education, coordinating, and briefing all the conventional
users. Small FBOs and remote airspace tend to host an easily-informed close
community of users.
 
IFR AWES Window
 
While most safety considerations tend to restrict AWES operations,
there are potential compensating factors. A major opportunity is to fly AWES
more freely during IFR conditions when such conditions result in an absence
of airtraffic (nighttime, low visbility, below IFR altitude minimums, and full
ATC determininism.

AWES Structural Load Case Analysis 

Large scale tether and membrane AWES have special structural characteristics and 
dependent operational methods. 
Ground Anchors are a critical component of many TA classes. Civil engineering 
and soil geology must integrate into tethered flight regulation. 

Many engineering fields become aviation related as systems grow complex. 

Load cases with time steps are used for dynamic analysis. Static stress 
analysis with linear material models/ Each load case has a set of forces, 
moments and nodal deflections. For natural frequency (modal) analysis each load 
case presents one mode shape and frequency. The first load case is the first 
natural frequency, second case- second frequency, and so on.  In heat 
transfer, each load case is a time step in transient analysis.
Group: AirborneWindEnergy Message: 5218 From: dave santos Date: 12/28/2011
Subject: Fw: FAA Notification for Airborne Wind Energy Systems (AWES)
Below is a sort of worksheet addendum to TACO 0.8, a last-chance preview before the finalized submission re-emerges. Please use material "share alike" for your own FAA docket submission, or even join in being a formal signitor to TACO 1.0.
 
I include the cover-note to my airman dad and industrial profiler pro bro', two more aces up our sleeves ;^)
----- Forwarded Message -----
From: dave santos <santos137@yahoo.com font-weight:bold;">Subject: FAA Notification for Airborne Wind Energy Systems (AWES)

Hi dad, Q,
 
Below are key parts of the recent FAA circular regarding kite energy, with some of my notes and answers penciled in. Please note this is all very rough still, there will be a lot of polishing before everything is officially submitted by Feb 6.
 
A lot of the FAA policy has already been informed by me and my friends. Things are moving along nicely, and a lot of interesting flying is about to happen,
 
'cito
 
 
 
=========
 
Notification for Airborne Wind Energy Systems (AWES)- The FAA seeks comments on revising its policy regarding the application of Title 14 of the Code of Federal Regulations (14 CFR) part 77, “Safe, Efficient Use and Preservation of the Navigable Airspace,to airborne wind energy systems (AWES). In addition, this notice requests information from airborne wind energy system developers and the public related to these systems so that the FAA can comprehensively analyze the AWES and their integration into the National Airspace System (NAS).

Background- During the past decade, there has been an increased focus on the use of clean renewable energy resources, including wind energy. The FAA has been approached by various entities, including manufacturers, scientists, engineers, and advocacy groups representing the wind energy community, who are researching the use of more sustained and consistent winds at higher altitudes where conventional ground-based wind turbines cannot reach. As part of their research, the energy community is examining various concepts for system designs to harness high altitude winds as a potential source of energy.

Airborne Wind Energy Systems (AWES) are described broadly as mechanical devices that are moored to the ground, via a tether or cabling component, for the purpose of capturing the fluid stream kinetic energy of winds. The kinetic energy captured by the device is then utilized in various fashions to generate electricity. In one option, the wind energy is immediately converted into consumable power, at the system component keeping the system aloft, and then transferred to the ground by a mechanical tether, cabling conductor, or other method. In another option, the combination of the wind, the aloft device, and the mooring cables are systematically utilized to drive an electrical generator located on the ground.

The basic overall components that comprise various AWESs are fairly similar in concept, however, the technologies and the specific devices that keep them aloft differ dramatically. Such devices have leveraged on similar engineering designs that apply to kites, balloons, kytoons, aircraft wings, aircraft, airfoils, as well as others.[1]

Although some of these AWES components could be covered by 14 CFR part 101, Moored balloons, kites, amateur rockets and unmanned free balloons, some conceptual designs include hybrid concepts or utilize new innovative techniques that are not as easily classifiable. For example, the FAA identified some AWESs employing “balloon-like design structures with motorized rotors for vertical and/or horizontal control, resembling a moored airship which does not fall within the category of 14 CFR part 101 devices.[2]  Additionally, the FAA also identified some AWESs that employ a moored kite or balloon with one or more wind capturing devices (wings or blades) attached along the mooring cable that spin a separate cable and activate ground-based power generators. Consequently, the FAA has determined that AWES are unique and would not fall under 14 CFR part 101.

Furthermore, since AWES is a relatively new technology that will be used to support clean, renewable energy initiatives, the FAA finds that part 101 does not currently contain the necessary provisions to address these systems.

Whether designed with conventional 14 CFR part 101 type devices or non-conventional hybrid-type components, each AWES possesses differing attributes. These attributes include, but are not limited to, its physical design, how it operates, necessary airspace utilized, radar cross-section, and reflection coefficient. The FAA is concerned with these differing attributes and their unknown impacts to the NAS, navigable airspace, and to the flying public. Therefore, the FAA concludes that each AWES deployment needs to be studied on a case-by-case basis with respect to the surrounding aviation environment to ensure aviation safety.

Policy- Given the altitudes that these structures can operate and their operating characteristics, the FAA concludes that they should be studied and the potential impacts to the navigable airspace must be identified and addressed. Presently, the FAA has an existing regulatory framework that outlines standards for determining obstructions to air navigation or navigational aids or facilities (see 14 CFR part 77). 14 CFR part 77 is utilized to evaluate the impact of wind turbines and other forms of renewable energy on the navigable airspace. Therefore, we conclude that any new forms of wind gathering devices would be included in the Obstruction Evaluation Process, which is administered under 14 CFR part 77.

Accordingly, the FAA announces that the provision of part 77 will apply to temporary AWES proposals that will be used for data collection purposes. The FAA finds that the provisions of 14 CFR part 77 can be applied to these structures without the need to amend the regulations. Permanent and operational AWES may be addressed in the future upon further evaluations and risk assessments are performed. The purpose of this change in policy is to allow for the continued development of this emerging technology and to provide the FAA with data regarding these devices so that the safety and integrity of the NAS is maintained. Persons proposing to conduct temporary airborne testing of AWES for data collection purposes must provide notice to the FAA pursuant to 14 CFR 77.13(a)(1), which requires notice of any construction or alternation of more than 200 feet above ground level.

In order to facilitate the timely manner in which AWES proposals are reviewed, AWES developers and operators are requested to limit temporary operations to the following:

(1) Airborne operations of AWES should be temporary in nature for testing and data collection purposes only;
(2) Single AWES devices only (e.g.—no “farmsor multiple simultaneous testing);
(3) AWES should be limited to a single fixed location (e.g.—no mobile ground facilities);
(4) Testing is confined to heights at or below 499 feet above ground level (AGL);
(5) Airborne flight testing of AWES will only occur during daylight hours; and
(6) AWES will be made conspicuous to the flying public. (The sponsor of the AWES will provide the FAA with their marking and lighting scheme. FAA Advisory Circular 70/7460-1K (AC 70/7460-1K), Obstruction Marking and Lighting, currently does not address AWES, but may be used as a guide, as some portions may be applicable.)

Request for Information- The FAA is working jointly with industry, the Department of Energy, as well as other airspace stakeholders, and believes that additional information from AWES developers would be beneficial. The information will assist the FAA as it considers long-term policies and guidance to integrate the AWES safely into the NAS.

The FAA has several concerns regarding AWES operations in the NAS, including:

(1) Impact(s) to various surveillance systems (radars);
(2) Conspicuity to aircraft (marking and lighting);
(3) Overall safety—safety to other airspace users, safety to persons and property on the ground, safety to the efficient and effective use of NAS facilities, safety to airports, safety to air commerce, and safety to the efficient operations and managing of the NAS;
(4) AWES fly-away protection (mooring cable is severed);
 
Redundant cabling, "kite-killers", tether cutaway,  programmed landing on site, alternate field landing

(5) AWES physical dimensions per unit and per farm;
 
Soft wings of about 100sq m and rigid wings of about 30sq m, based on current TRLs.

(6) AWES operating dimensions per unit and per farm (amt. of airspace it may require);
 
A standard utility scale kitefarm in round numbers- 2000ft high by 4000ft diameter or 600m high by 1200 diameter

(7) AWES mobility (potential for AWES to relocate from physical ground location to a different ground location); and
 
AWES Units and Arrays are in principle capable of ferrying themselves to working locations and maintenence and inspection centers.

(8) Wake turbulence or vortices of wind capturing component(s).

The FAA recognizes the various design concepts utilized by AWES developers for components of their overall AWES. These may include the components that keep the system aloft, the power generating equipment, the energy transferring equipment, the maneuvering controls, and the physical and operational dimensions, amongst others. Given these variations in technologies, the FAA seeks information from the industry to help us evaluate the potential risks of permanent AWES and AWES farms operating in the NAS.

The FAA is requesting AWES sponsors provide information on the following. Additional information may be requested upon further contact and coordination. This information must be submitted by February 6, 2012.

    * General information on a developer's specific AWES design concept and plans for operation.
KiteLab Group AWES KiteFarm Dense-Array Concept and Operations
 
○ What type(s) of mechanical devices are you employing to keep the system aloft?
Phased Ground Winch Towing
○ What are the physical dimensions of the device(s) with relation to the above?
Industrial Scale Winches of about 8 cubic meters in size.
○ What kind of materials will comprise this device?
Polymer cables and fabric aloft; industrial power machinery and civil engineered earth anchors at the surface.
○ What are the operational dimensions (requirement for airspace) for the system?
1/4 Scale- 500ft high by 1000ft diameter.  Full Scale- 2000ft high by 4000ft diameter.
○ Is there a requirement to operate more than one device in the air?
Many small crosslinked units would be intregrated as one device (Dense Array)
○ What are your long-term plans for this system?
Evolution to gigawatt scale energy within NAS regulatory demands.
○ Can you comply with marking and lighting requirements?
Yes.
○ Can you identify any impacts to your system when complying with current guidance for marking and lighting standards?
Impact of compliance is negligible.
○ What are your plans or how is your system designed to make the system conspicuous to the flying public?
The Dense Array concept has the highest inherent conspicuity. Use of FAA marking and lighting schemes is natural.
    * Safety to other airspace users and persons and property on the ground.
Sense and Avoid would be practiced by the PIC and VO team. The array should be able furl and drop out of the way of a wandering aircraft.
Low mass, low velocity flight units of fabric and cable are the least inherently hazardous of all AWES classes.
○ What safety mechanisms or devices have you designed into the system to ensure all aspects of aviation safety?
Quadruble redunancy- Passive redundant structure, double redundant manual/automatic failsafe devices, PIC/VO supervision
○ What safety mechanisms or devices have you designed into the system to minimize or mitigate hazards to persons or property on the ground?

   * Minimized risk to persons and property on the ground.
All flight units low-mass, low velocity, and redundantly constrained within the airfield.
○ What are your plans or how is your system designed to reduce a large radar cross-section and become less conspicuous to surveillance systems?
Polymer line and fabric is inherently radar transparent.
○ What are your plans or how is your system designed to reduce impacts to any communication or navigation systems supporting the NAS?
The Sense and Avoid principle can be applied to the design cycle. As a problem is discovered, the designer undertakes the burden remove it. The "rag and string" approach promises the least impact on legacy or future comm and NAV systems.

In addition, the FAA is requesting input from airspace users regarding the impact AWES would have on the NAS. Specifically, we request airspace users provide comments to the following. Additional information may be requested upon further contact and coordination. This information must be submitted by February 6, 2012.

    * What safety implications do you foresee of AWES operations with respect to your use of the airspace or your interest to the NAS?
    * Would you have any concerns about AWES permanently operating at altitudes above 500 feet AGL, but, under 1,999 feet AGL? If so, what and why?
    * If AWES were permitted to permanently operate in altitudes at or above 2,000 feet AGL, how do you foresee this as negatively impacting your missions, use of the airspace, or other interests in the NAS?
    * What other concerns and/or issues might you have with respect to AWES co-existing in the NAS?

Comments Invited- The FAA invites interested persons to submit written comments, data, or views. The agency also invites comments relating to the economic, environmental, energy, or federalism impacts that might result from adopting the proposals in this document. The most helpful comments reference a specific portion of the proposal, explain the reason for any recommended change, and include supporting data.

Under 14 CFR 11.35(b), the FAA is aware of proprietary information filed with a comment, the agency does not place it in the docket. It is held in a separate file to which the public does not have access, and the FAA places a note in the docket that it has received it. If the FAA receives a request to examine or copy this information, it treats it as any other request under the Freedom of Information Act (5 U.S.C. 552). The FAA processes such a request under Department of Transportation procedures found in 49 CFR part 7.

Issued in Washington, DC, on November 30, 2011.
Dennis E. Roberts,
Director of Airspace Services.
[FR Doc. 2011-31430 Filed 12-6-11; 8:45 am]
BILLING CODE 4910-13-P

Footnotes
1. 14 CFR 1.1 defines a balloon as a “lighter-than-air aircraft that is not engine driven, and that sustains flight through the use of either gas buoyancy or an airborne heater,and defines a kite as a “framework, covered with paper, cloth, metal, or other material, intended to be flown at the end of a rope or cable, and having as its only support the force of the wind moving past its surfaces."

2. 14 CFR 1.1 defines an airship as, “an engine-driven lighter-than-air aircraft that can be steered."
------------------
Add to TACO (notes)
bird-strike hazard to high speed AWES
emergency radar reflectance upon breakaway to meet Free Balloon standard; "decloaking"   


Group: AirborneWindEnergy Message: 5219 From: Bob Stuart Date: 12/28/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
We are dealing with subsonic speeds here, more than an order of magnitude slower than satellites, which barely encounter relativistic effects.  Like Newton, we can do our work without those considerations.  The explanation for the apparent stability of fast wings probably lies in careful consideration of the momentum of all masses present.  Computers can manage that now, or we could just develop rules of thumb in an empirical way.  The old rigger's books of the proper sizes for masts, ropes and spars were not improved much when engineering became available.

Bob Stuart
Sent from the Country formerly known as Nice.

On 24-Dec-11, at 4:54 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 5220 From: dave santos Date: 12/28/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
Bob,
 
Deep physics distracts us by its inhumanly large and small scales, including the persistent intellectual bias that relativity or quantum mechanics should be disregarded at the human scale (like macroscopic phonons in high sonic speed ballistic conductance).
 
Newton was onto a profound mass-energy in spacetime mystery with his spinning bucket of water (empirical and thought) experiments. We cannot think deeply about our real world rotation problems without the full symphony of historical ideas. Newton was not really explanatory enough (if only he lived today) and the new-fangled subtleties are often pregnant rather than sterile.
 
Of course we should also attend to the old riggers' art, just as you suggest, as enjoying the best of both worlds; too many of us do neither,
 
daveS

 
Group: AirborneWindEnergy Message: 5221 From: Pierre Benhaiem Date: 12/29/2011
Subject: Rigid or fabric wing?
DaveS,

It is a fact than (for my knowledge) no rigid kite as toy or game is on
the market.Nethertheless carbon composite rigid kites could be good for
records of speed.

Perhaps it is an indication in favor of soft kites.Do you think rigid
kite has an inherent instability (unlike non-tethered plane)?

PierreB
Group: AirborneWindEnergy Message: 5222 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
Why should something which is invisible at human scale not be disregarded, if, as you say deep physics distracts us?

Bob Stuart
Sent from the Country formerly known as Nice.

On 28-Dec-11, at 10:05 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 5223 From: Doug Date: 12/29/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)
I would not want to try and read through all this, but my overall sense is that such well-intentioned material may cause more harm than good, especially if initial assumptions upon which it is based prove incorrect, which is more than likely. Maybe you could reduce the size to a twitter post.
:)
Doug S.

Group: AirborneWindEnergy Message: 5224 From: Dan Date: 12/29/2011
Subject: kick-start-energy-technologies
Group: AirborneWindEnergy Message: 5225 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
Bob, you wrote- "Why should something which is invisible at human scale not be disregarded, if, as you say deep physics distracts us?"
 
I stated this poorly. The famously inhuman scales of physics dynamics do "distract" us so much as "blind". My conviction is that these effects are not "invisible at human scale" as you state, but quite tangible once we learn how to grasp them.
 
For example, a child on a spinning merry go round feels added acceleration kinestheticly; it can be measured by a simple scale. This is an actual increase in the total mass-energy of the child. Classical angular momentum seems like the whole effect; the mass-energy aspect barley budges to an accountant's notion of materiality, but mass-energy is fully coupled with spacetime as the truer system view, so the child's feeling the added G-force is truly the tip of the relativistic iceberg. Maybe we should not care what the tip of an iceberg really means.
 
The same scale blindness keeps us from seeing that lunar tides that any child can see working at the seashore are the manifestation of  true (lunar earth) "cosmic" gravity waves; even as most physicists lack the insight to see it quite so elementally. Until you reminded me yesterday of historical expert blindness, i had for years presumed that atmospheric and marine "gravity waves" where somehow a different animal tha cosmic gravity waves, but suddenly i see that they are visible manifestations of the exact same thing we hope to detect from spinning neutron star (or blackhole) pairs, they just look too different to the unprepared mind.
 
Even if such insights do not often directly inform us (how an autogyro rotor by acting more massive in the warped spacetime view  helps it shrug off turbulence (gyroscopic stability)), they prepare our imaginations for useful new insights. They have a deep poetic truth and wonder, although a humdrum engineer has no desire for such gifts. We, on the other hand, are blessed with this knowledge, and our ultimate AWES KIS designs will express deep physics most elegantly,
 
daveS

 
Group: AirborneWindEnergy Message: 5226 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
DaveS,

Perhaps you  might calculate the value corresponding to  ".....this is an actual increase in the total mass-energy of the child" effect you refer to, in order to see just how significant it is....and while you're at it, go ahead and calculate how much younger the child  is (upon stepping  off the merry-go-round) than his (now apparently older) hapless peers  who didn't take the ride with him :-)

Also, I would like to know the amount that this autogyro "space-time mass warpage"  effect improves the gust resiliency of an autogyro, say, compared to the "induced relative wind" effect upon the blade elements due to rotation.

A physics prof once said to me,  "....until you can evaluate a phenomenon numerically, you really know little about it"!  This corroborates nicely with the fixation (in all the physics classes I ever took) upon evaluating numerically the mathematical and conceptual ideas about which the teacher pontificated.  As I recall, in all the exams we took, they never asked us to "describe qualitatively" some aspect of a subject....rather it was always...."here is a circumstance and set of parameters......now, calculate such-n-such".

DaveL




At 11:34 AM -0800 12/29/11, dave santos wrote:
Group: AirborneWindEnergy Message: 5227 From: dave santos Date: 12/29/2011
Subject: Re: Rigid or fabric wing?
PierreB,
 
There are a few all-rigid kites, notably autogyro kites. Traditional people in strong wind regions, like the Maori, made good rigid kites with stiff plant materials.
 
Characteristic instability of hot rigid wings at slow speeds is loss of control authority and at high speeds is violent flutter and sudden tumbling. These states are carefully avoided in aeronautics.
 
Due to expense, fragility, high speeds, and so on, rigid wings are not suited for cheap kiddie toys, but they are great for fine model gliders, which routinely are towed by tethers to launch (bungee or winch). Sometimes the glider sticks on its tow hook and a good radio control pilot will fly just fine as a sweeping kite and land safely. A human glider pilot actively drops tether, not passively like most model aircraft, so gliders rarely get stuck on-hook, but they will fly in kite mode (connected tow-high) and clearly fly as towed kites. These are risky modes and require skilled piloting.
 
The current best working rig is an AWES hybrid of a very hot clean rigid power wing sweeping under a cheap soft pilot-lifter kite, both operating in their optimal flight envelope. We can even create arrays of these units in vast cross-linked formations,
 
daveS
 
PS Weak Links are a basic safety measure for towed kites, for example, if there is a reel-jam during a step-tow glide-away phase. The simplest weak links just break at a specified load, but this is not always a desirable response. A Smart Weak Link could reason about the multi-sensed situation and decide whether to release (coolIP).
 
 
 

 
Group: AirborneWindEnergy Message: 5228 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
DaveL,
 
We fully agree that the temporal effect on a child of a merry go round, as considered by the dimly-qualitative mindset of the average physics textbook writer, is "insignificant", while the spatial travel quantity is "considerable". This is a well-known qualitative bias, to presume the "tiny" quantity of one thing is of smaller consequence that a seeming far larger quantity of another thing. In fact both numbers offer true views of the same mass-energy space-time continuum.
 
So we are free to be astonished that the child is at all younger! As modern scientists, we happily confess such qualitative biases. We can even now quantify quality with tools like predicate calculus, and send post results as fully quantified binary code. We live in an ongoing intellectual revolution and such amazing feats are easy once you know how.
 
I grew up with many of those medieval texts you refer to (Texas invented the modern crappy textbook). Fortunately we had a few masterpieces to liberate us, like Feynman's Lectures on Physics and Farady's Natural History of a Candle.
 
daveS
 
 
 
  
Group: AirborneWindEnergy Message: 5229 From: dave santos Date: 12/29/2011
Subject: Re: Tethered Avation ConOps (TACO) v0.8 (coolIP)
Doug,
 
If AWE is not aviation, then you are right; let your post can serve as the tweet.
 
If AWE is aviation, then embrace the culture to "dance the skies". Enjoying
your TACO is a good start,
 
daveS
 
"High Flight"
Magee
The tumbling mirth
Oh! I have slipped the surly bonds of Earth
And danced the skies on laughter-silvered wings.
Sunward I've climbed, and joined the tumbling mirth
Of sun-split clouds—and done a hundred things
You have not dreamed of—wheeled and soared and swung.
High in the sunlit silence, hov'ring there
I've chased the shouting winds along and flung
My eager craft through footless halls of air.
Up, up the long delirious burning blue
I've topped the wind-swept heights with easy grace
Where never lark or even eagle flew
And, while with silent, lifting mind I've trod
The high untrespassed sanctity of space,
Put out my hand and touched the face of God.

 
  
Group: AirborneWindEnergy Message: 5230 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
DaveS,

OK, so we agree about the magnitude of the "relativistic-twin effect" on the child....then, might you now address the "merry-go-round", "space-time mass warpage" contribution to the autogyro's resiliency to gusts?

DaveL


At 1:42 PM -0800 12/29/11, dave santos wrote:
Group: AirborneWindEnergy Message: 5231 From: dave santos Date: 12/29/2011
Subject: ARPA-E AWE News on Twitter and Facebook
ARPA-E hides its poorly planned AWE funding and science-engineering strategy behind a porous wall icily maintained by the legal counsel. The AWE contest fiasco is just one aspect. Under growing political pressure to show some sign of intelligent life in its AWE program, the Agency has Tweeted and FaceBooked a link to Ted Greenwald's recent Makani article. What a poor substitute this is for the citizen's right to know exactly what its government is up to. To rely (apparently as "exclusives") on FaceBook or Twitter to "inform" us about AWE, with a link we already had, is a fine joke.
 
Ted Greenwald is a Bay-Area reporter with a talent for popular tech writing, and he does include Fort grumbling vaguely in this "ARPA-E approved" text. While Ted fails to address the AWE expert's need for precise information about the program, he somehow serves ARPA-E's purposes. We also see the new plague at work in the net with this piece, where a well placed story is quickly hosted by a thicket of commercially affiliated third parties pimping whatever, drowning out diversity, and clogging search results. The problem seems centered in Mountain View, CA ;*)
 
ARPA-E is invited to correct any misimpression above...
Group: AirborneWindEnergy Message: 5232 From: dave santos Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
DaveL wrote- "...might you now address the "merry-go-round", "space-time mass warpage" contribution to the autogyro's resiliency to gusts?"

Gladly.
 
If the spinning rotor mass were not dragging against space-time (warping it proportionally), it would not have the extra leverage to resist being kicked about by gusts as much as a non-rotating disc would be.
 
 
Now why would ever better physics fail to answer ever more questions?

 
  
Group: AirborneWindEnergy Message: 5233 From: Joe Faust Date: 12/29/2011
Subject: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

 JOEBEN BEVIRT
Application number: 13/048,693

Publication number: US 2011/0266395 A1
Filing date: Mar 15, 2011

Group: AirborneWindEnergy Message: 5234 From: blturner3 Date: 12/29/2011
Subject: Re: Rigid or fabric wing?
I think this is a good comparison. Of course AWE may have large differences but I think the relative costs will show a lot of correlation. I would suspect that the rigid wing has more expensive raw materials but still has a lot more labor than the soft wing. With scaled up production I think the difference in cost would narrow but still favor the soft wing on a initial cost basis. I also think that even with the additions needed to make the lifespans match the soft wing would still come out ahead. However the higher performance of the fixed wing could significantly change the outcome to favor it.

Most of the large players in AWE should have done this comparison and clearly they have not come to the same conclusions. The graphs that I have seen have had bias toward whatever camp they were in. It would be helpful to have a public rundown of where the cost/performance curves cross.

What is missing in this is the glide ratio of the fixed wing. I could not find it on their site. It may be in there as I don't speak french. As you note the tether damages the higher glide ratio more than the lower one. I don't know where we would find or calculate that.

Brian


Group: AirborneWindEnergy Message: 5235 From: dave santos Date: 12/29/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
Sheathed kite tethers are at least as old as Pocock, who used silk sleeves to integrate his multi-lines. Aerodynamic cable sheaths with multiple contents are also known in many related fields, like racing sail headstays and paraglider rigging. Even oval outer-braid kiteline has long been considered a (slight) aeroadvantage. The idea is obvious, and the many documented versions will emerge, just as when we found all sorts of prior art ready to invalidate Makani's faired-tether patent. This "sheath" version is yet another well funded Bay Area troll patent with no inventive leap.
 
Of course faired tethers are not a critical advantage, but a marginal trade-off. The obvious work-around to this patent is to use ordinary line with confidence, or tether sheaths as multi-conduits, just a Pocock did, and let any aerodrag advantage be incidental. We can look forward to someday fighting these patents as paid experts.

 
  
Group: AirborneWindEnergy Message: 5236 From: blturner3 Date: 12/29/2011
Subject: Re: kick-start-energy-technologies
Thanks for the link. Good reading.

Brian
Group: AirborneWindEnergy Message: 5237 From: Bob Stuart Date: 12/29/2011
Subject: Re: kick-start-energy-technologies
The US federal government doesn't have a "structrual" problem, it has a corruption problem.  Energy systems should be taxed or subsidized according to their damage and depletion of the earth, not their support for candidates.

Bob Stuart
Sent from The Country Formerly Known as Nice.

On 29-Dec-11, at 11:33 AM, Dan wrote:


Group: AirborneWindEnergy Message: 5238 From: Dave Lang Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
DaveS,

What might one need to add to a "classical Newtonian analysis" of an autogyro rotor to properly incorporate this "space-time mass warpage" contribution to autogyro stability?

DaveL



At 3:45 PM -0800 12/29/11, dave santos wrote:
Group: AirborneWindEnergy Message: 5239 From: dave santos Date: 12/29/2011
Subject: Fw: [AWES] Physics of Rotating AWES Wings (Doug, RobertC; Please for
 
 
Classical Newtonianism does not address warped space-time, or mass-energy equivalence. Adding these concepts give us a better "why" for how a spinning rotor resists perturbation. Early ideas were usefully predictive, like knowing one's local volcano eruption subsides soon after a virgin is thrown in. We actually got a long way with just four elements. But clinging to these frameworks slowed further progress.
 
What new science first gives us is a better explanation of old chestnuts (The egg came first, the first chicken came from an egg-laying ancestor.). The enhanced precision of relativistic predictions is more a moral comfort than a ready tool. Eventually the new explanations bear practical fruit, answering Doug's exam question; "what good is a baby(?)".
 
Let us look under every rock on our quest, but not get stuck on any single controversy, like whether Newton's physics inspire us properly (in the absence of a paycheck) to invent, say, spiral-wave rotor/tether kite-train systems stretching skyward, such as have never been imagined before. For the open AWE world, the cool new physics is a real job perk, a needed competitive edge over many a well-paid Newtonian VC drudge working on the same problems.
 
In AWE, best physics wins!
 
daveS
 
PS A stretched tether is formally less entropic (it borrows order from outside) than a slack tether. This thermodynamic view is fully non-Newtonian.

 
  


Group: AirborneWindEnergy Message: 5240 From: Pierre BENHAIEM Date: 12/29/2011
Subject: Re: Rigid or fabric wing?

Brian,

Extract from another link
Features - AERIANE:"- Weight (with harness) 48 kg- Glide ratio with closed cockpit 27 @ 75 km/h
- Open cockpit 21 @ 65 km/h - Glide ratio at 120 km/h  16".

So 21² = 441,and  6 times 8.573² (per m²).

Of course these estimations can not be quite exact since the angle of incidence is generally higher for a kite than for a (even) soft glider.,and
ratio L/D 8.5 for a paraglider is perhaps a too high value for a soft kite (which usually L/D does not exceed 5).

Calculation gives a rough idea but with evolutions of technologies what is good one day is not good the next day.

PierreB



Group: AirborneWindEnergy Message: 5241 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
The way I learned it, the moving object gains mass and is thus a part of the space-time continuum with its large-scale accounting of mass and energy patterns, but the effect can safely be neglected, like the downward pressure of sunlight on our kites.  Sun pressure is clearly revealed by any radiometer, and by the new solar sailing satellites, but never entered into calculations for our speed range.  

If you are having trouble accounting for the apparent inertia of a airfoil, the first place to look might be the air around it.  That was what limited the roll rate of the Gossamer aircraft.  The entrained air weighed far more than the wing itself.

The "Gravity Waves" in the physics news about new discoveries are the equivalent of the wave nature of light.  Michaelson and Morley famously demonstrated that light behaves as both a particle and as a wave, with the simple double-slit experiment.  There is no such apparatus handy for gravity, so clues are being teased out from extremely close observation.  Gravity as a force is well described, and in combination with a rotating body, like Earth, will produce tides.  In doing so, the momentum of the earth is slowly transferred to the moon, giving us longer days, and more annular eclipses as the millennia go by.  

Billy Connolly argues vehemently that our Solar System is an atom to bigger beings, and that our atoms contain another infinity.  I can't prove him wrong, but I think that is too broad an analogy.

Bob Stuart

On 29-Dec-11, at 1:34 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 5242 From: Bob Stuart Date: 12/29/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertC; Please forgive ;^
I have found very little practical use for my knowledge of Einstein's work, etc, but continue to find new vistas in just doing the mundane accounting of energy exchanges.  The kinetic energy loss of a thrown rock corresponds to the surface energy created by the subdivision of a window pane.  The Cook-Gordon mechanism for creating and harmlessly redirecting cracks is how we make tough fiberglass moldings from brittle glass and brittle resin.  The kinetic energy of a blow can be revealed by the white appearance of new internal surfaces.  It does not matter that a miniscule portion of the rock had also gone through a mass-energy transference during the process.

Bob Stuart

On 29-Dec-11, at 9:24 PM, dave santos wrote:


Group: AirborneWindEnergy Message: 5243 From: Pierre BENHAIEM Date: 12/29/2011
Subject: Re: Offshore submerged water turbine kite driven?
What sort of water turbine?Marine turbines work for a maximal current of 3 m/s,good speed for tidal but not enough as AWE conversion system.Could classical motor-propeller work as generator in higher speed with a device anti cavitation?

PierreB



Group: AirborneWindEnergy Message: 5244 From: Bob Stuart Date: 12/29/2011
Subject: Re: Offshore submerged water turbine kite driven?
If cavitation should become a problem, deeper submergence would solve it.  It becomes a problem on propellers because they are pushing the envelope on diameter and depth.  A focus on efficiency is usually enough to keep out of cavitation range.

Bob Stuart

On 29-Dec-11, at 10:09 PM, Pierre BENHAIEM wrote:


Group: AirborneWindEnergy Message: 5245 From: Doug Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
Thanks for that heads-up Joe:
Just had a moment to glance at this patent application. I'd have to call claim 1 way too broad. Seems to me a sheath around the tether is not only obvious, but has been discussed here, on this list, previous to the March 15, 2011 filing date? We have a guy in regular wind energy who was able to patent something we had talked about online too. It was filed about a month after we discussed it online. Easy to invalidate.

To me, the idea that nobody thought of putting a tether in an aerodynamic sheath is kind of ludicrous. Things don't get much more basic than that.
For the much-discussed-here aerodynamic tether, tether fairing, etc. there would be two natural choices:
1)the tension-carrying member is separate from an aerodynamic shell (like constructing a blade around a spar) or
2) the aerodynamic shape includes a tension-carrying member.

I also don't think that simple ideas like that, in lieu anything new or unexpected, should even be patentable. I could be wrong, but, skimming along through the rest of the claims, I think I've seen most of the claims in this patent application discussed on this list in the past, quite likely before the filing date. That would be something to check.

Unless anyone wants to pay a third party for every time you want to put an aerodynamic sheath around their tether, you might want to dig up some prior art. Likely, you don't need to go past the archives of this discussion list. Wayback machine is also a great online tool to see what WAS posted on the web, and when.

Patents are great when you really have thought up something new that nobody else had thought of. But when the goal is to carve out huge swaths of intellectual territory by slamming the system with spaghetti to see what sticks, hoping nobody will notice claims already in the public domain, that is not so good.

Searches for prior art can be very difficult, so in arcane and unknown arts, there are many (provably invalid) patents issued for ideas that were discussed previous to the filing date. Kind of like when Columbus "discovered" America. It was already inhabited.

Likely an overworked attorney couldn't (didn't want to) find any prior mention of an aerodynamic sheath and figured his client might have been the first to mention the idea publicly. More likely they imagined the similarly-overworked patent examiner not having time to dig up the prior art, or not knowing where to look, since the examiner may be handling a water pump one day and a jet engine the next, not focused on AWE per se. Luckily the examiners are easy to contact and the system is reasonably easy to negotiate.

Patent claims are a negotiation process, so it is not unusual to start the bargaining from an unrealistic beginning point. Many folks think just slamming invalid claims through the system is worth the expense. Odds say that the occasional slam-dunk can make it thru the system if nobody is vigilant. That's when the community as a whole has got to help the examiners and the system do its job. The patent system belongs to all of us, and invites the participation of anyone and everyone who is affected or involved, and really that active participation is essential since the examiners need guidance and feedback from the affected community to remain relevant and in touch with the art.

Doug S.

Group: AirborneWindEnergy Message: 5246 From: Joe Faust Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES

Thanks, Doug. 
1. Do examiners receive email input?  I have never written to a patent examiner.  I have trusted examiners to spend 5 seconds with Google, but then fewer fees would be collected if they pushed away proposals for reason of prior art; my guess is that millions of dollars are spent in allowing the system to be poor in tech prior-art finding; let the applicants spend their money!  Just let the public courts solve disputes in the future; why discourage an enthusiastic applicant?  Maybe a patent stands until someone squawks; no one really needs to look at prior art, except to put up some very incomplete near prior art in order to slip through the proposed novelty.   Just maybe no one will need to squawk.   But when things get really big in commerce, then fights seem to flare.  Hey, that guy is using my streamlined-compound tether!!!!  Go to court and show how the government used streamlined tethers during WWII that had electrical conductors within the sheaths. Lawyers will love the dance. 

2. For over half a century balloons and torpedo guard systems have used streamlined cases for tethers.
  
3. For many decades the kite tether in the kite hang gliders have known and used streamlined main-hang-line tether, but most popularly skipped for a preference for simplicity. 

4. Sheathed tethers for fluid sounding devices is common art. 

5. AWES has its categories: The simple kite system of an Eddy wing in hand converts wind energy that moves the hand and arm of the operator. Anyone skilled in fluid arts caring for drag of tether knows about streamlining lines, cables, stays, etc. Such streamlining via shape and sheaths is mentioned throughout the 1900s in patents; aviation is saturated with streamlining lines and cables. 

Two seconds, found: 
Group: AirborneWindEnergy Message: 5247 From: dave santos Date: 12/30/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;
Bob wrote-
 
class="yiv1950479827webkit-block-placeholder" limited. The higher mass would actually help maintain a higher roll rate if it was highly accelerated (by an unwanted gust).

first interest us, but the fermionic cases are also fascinating. Its a bit early to express these ideas clearly, but a plucked tether hosts fermionic-like phonons, the harmonic nodes define the bounds of "holes". A tether transmitting tug has bosonic behavior, a macroscopic quantum case of "ballistic conductance". Ballistic conductance apparently has two aspects, compression (like a pool cue or the swinging balls exec toy), or tension, with specially associated phonons. A tense tether is a case of one-dimensional stiffness, stiffness being a key to good ballistic phonon conductance. Lots to study!

 
vehemently that our Solar System is an atom to bigger beings, and that our atoms contain another infinity.  I can't prove him wrong, but I think that is too broad an analogy.
 
Bill's conjecture is age-old and plausible. If he is able to relate his intuition to observable evidence, he might be fit to work on kites,
 
 
Note- RobertCr and RobertCo should be distinguished in the subject line (RobertCo intended, with his concern for good science on this list)

 
Group: AirborneWindEnergy Message: 5248 From: Bob Stuart Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
How much has been changed by the new "First to File" regulation?  I'm concerned that new ideas can't be put into the public domain even if that is the inventor's wish.

Bob Stuart
Sent from The Country Formerly Known as Nice.

On 30-Dec-11, at 11:25 AM, Doug wrote:


Group: AirborneWindEnergy Message: 5249 From: Bob Stuart Date: 12/30/2011
Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;

Bob Stuart
Sent from The Country Formerly Known as Nice.

On 30-Dec-11, at 1:01 PM, dave santos wrote:


You asked for correction, are loosing the vote, and have not provided any supporting documents for your point of view.  As for the balance of this post, I'd rather work out the Allen-Bradley Retro Entabulator first:  http://www.youtube.com/watch?v=lBp5ag6SJH4

Bob Stuart



Group: AirborneWindEnergy Message: 5250 From: Pierre BENHAIEM Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
The patent pending from Makani (see FAIRED TETHER FOR WIND POWER GENERATION SYSTEMS - Patent ) describes (discloses?...see the four  "y" in the search report) an aerodynamic tether.Joby describes the same as a tether within an aerodynamic seath...Sharing of tasks...

PierreB 




Group: AirborneWindEnergy Message: 5251 From: Pierre BENHAIEM Date: 12/30/2011
Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
Attachments :
    To see the patent pending from Makani and the search report.

    PierreB




      @@attachment@@
    Group: AirborneWindEnergy Message: 5252 From: Joe Faust Date: 12/30/2011
    Subject: Re: TETHER SHEATHS AND AERODYNAMIC TETHER ASSEMBLIES
    First to invent (FTI) and First to File (FTF) are distinct from "public domain" matters.    Filing an application for patent protection for something that is in public domain does not compute.     An inventor having not put his or her invention into public domain might by FTF be sidelined by a secondary-later "inventor", especially if the invention was NOT in public domain.      A patent granted may be shown to be empty of rights, if a court finds that the matter was already in public domain which fact was missed by the patent process; this can be an expensive process.   In FTF, a secondary later "inventor" can win patent protection, but not if the matter was in public domain, only if the original first inventor simply failed to either put the matter into public domain or failed to put the matter into practice or file; the secondary "inventor" who files and puts into practice may thus win in FTF, even though he or she was not the first to invent.   

    Group: AirborneWindEnergy Message: 5253 From: dave santos Date: 12/30/2011
    Subject: Re: Physics of Rotating AWES Wings (Doug, RobertCo; Please forgive ;
    Bob,
     
    The Retro Entabulator is a hoot! Please do work it out ;) But pure comedy is far less serious in intent than understanding everything we can about kite physics, even if our efforts proceed just as laughably. The high rhapsodic potential of technical expression is still a rare taste. It was wonderful how old Bucky Fuller tripped out-loud on reality, rather than as a mental patient. I thought i did offer "supporting documents" for the open-imagination high-ground (Feynman, Faraday). Wikipedia can back up basics, like phonon-as-boson, and what-would-a-graviton-be(?).
     
    Your are right to say Einstein made "corrections" to Newton, but note that no one has discarded Newton. We just disagree whether the corrections represent a truth profound enough for us to value pondering as AWES engineering intellectuals or whether such truths lead to break-throughs. I have not rested my case yet, but am preparing it. Of course if we do a lot of tangible AWES R&D, we evade the charge of being sterile dreamers, and even earn a proportional right to speculate wildly.
     
    I am unaware of specific corrections made to the "New Physics" conjectures. It was certainly always conceded that subtle physics can be ignored by mere technicians in common fields. But its still the case that if the "small" effects were somehow removed (like unwarping spacetime) then these "simple" mechanisms would stop working. When you assert "engineers have to focus on the numbers they can affect" we find common ground. All engineers are of course affecting relativistic quantites and can calculate real solutions from them, by logical equivalence, if awkwardly.
     
    It should be clear that voting on an online forum is not how we best judge science ideas, but that truth (or the quest for it) is the essential ingredient. Even so, add Doug as an extra "vote" against dissatisfaction with current "flat earth" orthodoxies rampant in the backwaters of modern science ;*)
     
    daveS
     
    PS We are due for another fertile iterative romp thru kite thermodynamics, information theory, embodied field computing, chaos control theory, etc. It may turn out that basic kids' toys are universal encodings of the deepest secrets we can ever enjoy.
     
    Group: AirborneWindEnergy Message: 5254 From: dave santos Date: 12/30/2011
    Subject: Re: Basis for Makani R&D Claims?
    Corwin,
     
    There is widespread agreement with Dave Lang on essentially the same point you pose, that the Makani/Google AWE venture model has been "a focused effort at the expense of other options that are considered more viable". The blame for five years of unbalanced US AWE R&D investment is laid on Google management, and those who advised them, not Makani's hard working staff engineers.
     
    While, as you state, "early work at Makani (with a much larger team) was broadly focused on evaluating many architectures", there were conceptual gaps in this small program. Many outside of Makani worked productively in these overlooked areas. As a global community we advanced the TRLs of all major AWES contenders. Dave Lang worked out the potential for AWE autogyros; others worked on hybrid configurations, mega-scalable linked-array formations, novel passive flight stabilities, low-complexity (KIS) solutions, and so on. We did hundreds of unique scale-prototype tests. Makani is not known to have deeply explored many of these architectures, and much of their vast promise still remains to be discovered.
     
    We appreciate that you are "singularly focused on (y)our current architecture". We count on the Makani architecture to provide a credible economic and performance baseline for other architectures to try to beat. This is the key deliverable for the US taxpayer's early three-million dollar investment in Makani. Fort Felker's excellent framework is the relevant DOE standard for Makani to ace in its pending economic analysis, with due regard for the costs of regulatory compliance, critical reliability, liability, etc.. All major AWES architectures should undergo consistent formal review to these standards, so decision makers have the soundest basis for proceeding boldly (rather than relying on weak products like NearZero energy policy panels).
     
    An exciting phase is pending, where we fly-off the maturing architectures against each other, by real-world testing and a well developed scoring matrix, with third-party validators judging. When this due-diligence is complete, major investment can take its cue.
     
    Makani/Google should scrap the failed VC ethos in order to work cooperatively (as equals in every sense) with the global AWE community, and best meet Dave Lang's goal, that the "superior scheme...speak for itself in terms of results"
     
    dave santos
     
    KiteLab Group
    AWEIA Member