Rule2022-27993
Airborne Wind Energy Systems (AWES) Policy Statement
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
December 23, 2022
Effective
December 23, 2022
Issuing agencies
Transportation DepartmentFederal Aviation Administration
Abstract
FAA is finalizing its policy on the applicability of regulations concerning the safe, efficient use and preservation of the navigable airspace to all airborne wind energy systems (AWES).
Full Text
<html>
<head>
<title>Federal Register, Volume 87 Issue 246 (Friday, December 23, 2022)</title>
</head>
<body><pre>
[Federal Register Volume 87, Number 246 (Friday, December 23, 2022)]
[Rules and Regulations]
[Pages 78849-78852]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2022-27993]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 77
[Docket No: FAA-2011-1279]
Airborne Wind Energy Systems (AWES) Policy Statement
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Policy statement.
-----------------------------------------------------------------------
SUMMARY: FAA is finalizing its policy on the applicability of
regulations concerning the safe, efficient use and preservation of the
navigable airspace to all airborne wind energy systems (AWES).
DATES: This policy is effective December 23, 2022.
FOR FURTHER INFORMATION CONTACT: Brian Konie, Airspace Rules and
Regulations Team, Air Traffic Organization, Federal Aviation
Administration, 800 Independence Avenue SW, Washington, DC 20591;
telephone: (202) 267-8783; email: <a href="/cdn-cgi/l/email-protection#2240504b434c0c494d4c4b47624443430c454d54"><span class="__cf_email__" data-cfemail="9ffdedf6fef1b1f4f0f1f6fadff9fefeb1f8f0e9">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION:
I. Statutory Authority
Congress, pursuant to 49 U.S.C. 44718, mandated that the Secretary
of Transportation require the public to provide notice to FAA of ``the
construction, alteration, establishment, or expansion, or the proposed
construction, alteration, establishment, or expansion, of a structure
or sanitary landfill when the notice will promote (1) safety in air
commerce; (2) the efficient use and preservation of the navigable
airspace and of airport traffic capacity at public-use airports; or (3)
the interests of national security, as determined by the Secretary of
Defense.'' Moreover, under that section, the Secretary is required to
conduct an aeronautical study to decide the extent of any adverse
impact on the safe and efficient use of the airspace, facilities, or
equipment if the Secretary decides that constructing or altering a
structure may result in an obstruction of the navigable airspace, an
interference with air or space navigation facilities and equipment or
the navigable airspace, or, after consultation with the Secretary of
Defense, an adverse impact on military operations and readiness. FAA
codified these requirements in Title 14 of the Code of Federal
Regulations (14 CFR) part 77 and identified the form and manner in
which a person must submit notice.
II. Background
In 2011, FAA published a notice of policy and request for
information (Notice) stating its policy on the application of 14 CFR
part 77 to temporary AWES.\1\ The Notice also contained a request for
information from AWES developers and the public on these systems so
that FAA can
[[Page 78850]]
comprehensively analyze AWES and evaluate the potential impacts of
their long-term integration into the National Airspace System (NAS).
---------------------------------------------------------------------------
\1\ Notification for Airborne Wind Energy Systems (AWES), Docket
No. FAA-2011-1279 (76 FR 76333, Dec. 7, 2011) (Notice).
---------------------------------------------------------------------------
The Notice stated that the Obstruction Evaluation process under
part 77 applies to any new forms of wind gathering devices, including
temporary AWES proposals.\2\ This allowed the FAA to gather data about
these devices while the technology continued to develop.\3\ The notice
explained that anyone proposing to conduct temporary airborne testing
of AWES for data collection purposes must comply with part 77,
including the requirement in section 77.13(a)(1) that requires notice
of any construction or alternation of more than 200 feet above ground
level (AGL).
---------------------------------------------------------------------------
\2\ Id. at 76334.
\3\ FAA also stated in the Notice that it may address permanent
and operational AWES under part 77 in the future after further
evaluation and risk assessments.
---------------------------------------------------------------------------
Airborne wind energy (AWE) is the conversion of wind energy into
electricity using tethered flying devices.\4\ An Airborne Wind Energy
System (AWES) is a temporary or permanent structure, which consists of
a self-supported airborne system tethered to a ground station, with an
airborne or ground-mounted drivetrain used to convert kinetic energy in
the wind to mechanical power for purpose of generating electricity. The
tethered aspect of AWE provides the opportunity to harvest stronger and
more consistent wind found at higher altitudes.\5\
---------------------------------------------------------------------------
\4\ <a href="http://www.energy.gov/eere/wind/articles/new-report-discusses-opportunities-and-challenges-airborne-wind-energy">www.energy.gov/eere/wind/articles/new-report-discusses-opportunities-and-challenges-airborne-wind-energy</a>.
\5\ Id.
---------------------------------------------------------------------------
While many AWES are similar in concept (designed to harvest kinetic
wind and create consumable power), the technology and individual
components, specifically the aloft portion, differ dramatically.
Regardless of entity-specific design and potential resemblance between
designs, each AWES possesses different attributes. Due to different
attributes and impacts on NAS, FAA concluded that it must study each
proposed AWES deployment on a case-by-case basis to analyze the
surrounding aviation environment and ensure aviation safety.
III. Request for Information
In the Notice, FAA identified concerns regarding AWES operations in
the NAS, (e.g., conspicuity to aircraft via marking and lighting),
desired operational airspace volumes, potential impact on various NAS
facilities (e.g., communication, navigation, and surveillance), and
overall safety. These concerns remain relevant to FAA's management of a
safe and efficient NAS for all users.
In addition to operational concerns, FAA also recognized the
various design concepts AWES developers use for individual AWES
components. These varying concepts 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. Given the variation in potential AWES design, operations,
and technologies, FAA requested information from the industry in the
Notice. Examples of information requested included design concepts and
safety mechanisms; the type, material composition, and physical
dimensions of mechanical devices employed to keep the system aloft; and
long-term plans for this system. FAA also requested information to
determine if proponents could comply with existing marking and lighting
requirements and to discern how an AWES will be conspicuous to the
flying public.
IV. Summary of Comments
In response to the Notice, FAA received 20 comments during the
comment period. Eight comments came from individuals and 10 comments
came from major organizations or industry stakeholders. Six of the ten
major organization or industry stakeholder commenters were from
companies developing various types of AWES (Altaeros Energies, Inc.,
EnerKite GmbH, Highest Wind, LLC, Makani Power Inc., SkySails GmbH, and
Windlift, LLC); two were from organizations or associations
representing the wind energy industry (Airborne Wind Energy Consortium
(AWEC) and Airborne Wind Energy Industry Association (AWEIA)); and, two
were from associations representing the aviation industry (Experimental
Aircraft Association (EAA) and National Agricultural Aviation
Association (NAAA)). Of the 18 comments, 11 supported FAA's AWES policy
and 7 opposed the policy. Of the seven comments that either wholly
opposed AWES operations or supported change to enable safe AWES
operations, four supported traditional marking and lighting per FAA
Advisory Circular (AC) 70/7460-1, Obstruction Marking and Lighting,\6\
and two expressed support for part 77 notice and analysis.
Additionally, 13 of the 20 comments received provided additional
recommendations.
---------------------------------------------------------------------------
\6\ Available at <a href="https://www.faa.gov/regulations_policies">https://www.faa.gov/regulations_policies</a>.
---------------------------------------------------------------------------
FAA summarizes and addresses those comments responsive to the
Notice.\7\
---------------------------------------------------------------------------
\7\ The FAA does not address comments that are not responsive to
the request for information in the Notice.
---------------------------------------------------------------------------
1. Proposed system designs. While specific designs vary, based on
comments received from industry, FAA finds general consistency in a
three-part design with an aloft portion attached to a ground station
via a mooring cable, tether, or similar device. Altaeros Energies'
aloft portion is an inflatable shell filled with helium; EnerKite and
SkySails' is similar to a textile kite; Highest Wind's concept
resembles an autogyro; and Makani and Windlift plan for a wing made
from lightweight rigid or flexible fabric wings, respectively.
The material used for the tether or similar device varies across
system designs, e.g., carbon fiber, interwoven copper cable, or
polyethylene (Dyneema\TM\) fibers. These designs incorporate control of
the aloft portion to maximize wind energy capture from either the
ground station or from a segment of the aloft system, e.g., a module
suspended below the canopy. The aloft portion of some proposed (called
fly-gen) systems are generally static, generating electricity aloft and
transferring it to the ground station, while other proposed (called
ground-gen) systems use a winching system to generate electricity
within the ground station. The size of the aloft portion varies within
models from singular companies and across companies, with Highest
Wind's test article a smaller size than their planned operational
model. Additionally, some ground stations incorporate a mobile design
to enable ease of transport and portable use.
2. Airspace, operational, and safety considerations. Many industry
comments provided conceptual discussions of their systems and indicated
that the companies remain in the testing phase. Based on the nature of
the aloft portion's need to move (while tethered to a fixed ground
station) for electricity generation and the stated desired altitudes
for harvesting wind energy, the systems have different desired
operational airspace volumes.
While comments focused on operational altitude, four commenters
submitted diagrams that also considered the lateral airspace aspect,
e.g., operations to 2,000 feet AGL at a 30-degree altitude requires a
lateral distance of 3,500 feet. Some commenters integrated safety or
buffer zones into their proposed airspace plan
[[Page 78851]]
to depict the area needed to mitigate the safety risk to other airspace
users and persons and property on the ground.
Altaeros completed testing below 200 feet AGL and all industry
commenters expressed interest in either testing or sustained operations
below 2,500 feet AGL. Five commenters expressed their desire to conduct
uninterrupted testing during the day and at night over a period of days
or months to replicate a realistic operational environment. As of 2011,
SkySails tested aboard vessels at sea.
EAA believed that the deployment of AWES systems above 500 feet AGL
will have an adverse effect on recreational and general aviation flight
safety operations. EAA and other commenters suggested conducting
initial tests or data collection in established prohibited and/or
restricted areas before allowing AWES access to the rest of the NAS.
One non-AWES industry commenter remarked that creating more special use
airspace is invasive to an already crowded NAS. Another commenter
expressed concern about potential conflict between AWES and other
aircraft and suggested AWES deployments at the same altitude as
existing terrain.
Companies planned to test and operate in either single
configurations or in small (e.g., 3-5 units) or large (e.g., 300 units)
farms on land or offshore. Highest Wind asserted that they can find
willing private landowners underlying Class G airspace, where there is
virtually zero air traffic below 3,000 feet AGL, to host testing.
Additionally, Highest Wind requested that FAA ``designate a specific
number of no-fly zones up to 2,000 feet AGL over private lands'' for
testing and development purposes to reduce any burden of marking and
lighting. NAAA stated that AWES deployments could render blocks of
farmland untreatable by air, as aerial crop protection pilots would
avoid the entire AWES ``cone of flight'' considering the shifting
location and angle of an AWES due to wind variations. An aerial
application (part 137) flying service commenter opposed AWES and
believes they are a safety risk to agricultural and general aviation.
The commenter stated that the amount of affected airspace would
severely disrupt aviation.
A pilot expressed safety concerns about the ability of an AWES'
aloft portion to remain attached to the ground station in adverse
weather and the length of time it takes to return the aloft portion to
the surface. Industry commenters provided numerous proposed safety
methods specific to their system design and its capabilities. Altaeros
commented that they rely on established aerostat practices and that
their device has a valve to quickly and safely lower the device during
an emergency, e.g., tether failure. EnerKite stated that its system has
weak links, a pyrotechnical cutter, and soft wings to minimize any
safety risk. Highest Wind commented that their system's ``anti-
collision lights and on-board alarm'' comprise their safety
considerations. Makani commented that their system is unique from other
obstructions and its aloft portion can transition to a stationary hover
and land within minutes in case of an emergency or, in case of a tether
failure, land the aloft portion at a pre-determined point. SkySails
commented that it intends to mark and light its system and, if the
aloft system escapes its mooring, the aloft portion will sink to the
ground. Additionally, SkySails' system has internal systems to monitor
performance and recover the aloft portion as needed due to an emergency
and suggested charting AWES to enhance safety. Windlift commented that
their system can either quickly retrieve the aloft portion (reel in at
10 meters per second) or fly the aloft portion toward the ground (30
meters per second) to bring the aloft device below 500 feet AGL in less
than 6 seconds.
3. Marking and lighting compliance. Sixteen comments mentioned the
risk to aviation safety and 13 comments mentioned either marking or
lighting--the primary methods that enhance an obstacle's conspicuity
for a pilot to see and avoid. Comments ranged from providing full
support of FAA's marking and lighting schemes to suggestions of
alternative means based on the inability to comply with traditional
marking and lighting due to system design.
EAA supported adequate marking and lighting controls for AWES equal
to that required for other obstacles. NAAA expressed safety concerns
with AWES, specifically the ability of pilots operating at low levels
to see and avoid the tether. NAAA explained that a thin AWES tether may
prove indistinguishable from the background depending on the time of
day and weather conditions and recommended a strobe light on each
individual structure and lighting on the tether. To NAAA, properly
marked and visible obstructions are a life or death issue for low-level
operators. An experienced general aviation pilot expressed AWES safety
concerns based on low-level accidents involving MET towers and the
difficulty pilots may have seeing an AWES during the day and at night.
A part 137 commenter added that aircraft commonly operate safely at
altitudes less than a proposed AWES operation and a pilot could mistake
the aloft portion of an AWES as another aircraft disregarding the
possibility of a tether and inviting disaster. This commenter also
stated that the airfoil of AWES would need to be painted and lit and
that the tether would need high-visibility strobes positioned at
regular intervals to achieve a visual effect.
AWEC proposed a high-intensity light on the airborne portion of the
system, flashing at regular intervals at a fixed altitude or flashing
at the top and bottom of the (circular) flight path. AWEC proposed to
not mark or light the tether, claiming tether drag will prevent an AWES
system from achieving desired levels of performance.
Altaeros proposed lighting the structure using a high-intensity
blinking light on top of the aloft portion, glow lighting or
illumination of the aloft portion from the inside, or one or more
spotlights aimed from the ground. Altaeros supported lighting the
aerostat and not the tether.
EnerKite's proposed system has brightly colored wings that can have
red markings to increase conspicuity. EnerKite commented that decreased
weight and movement of the system are substantial factors in system
efficiency, thus rendering large obstacle marking infeasible.
Additionally, EnerKite stated that flags generate considerable drag and
complicate the dynamic extension and retraction of the system. EnerKite
stated their system's movement at variable tether lengths also
increases conspicuity and proposed the construction of a nearby
obstacle with traditional marking and lighting for further enhancement.
EnerKite indicated their ability to illuminate the wing from the ground
or the nearby obstacle.
Highest Wind commented that current marking requirements in AC 70/
7460-1 are overly burdensome and existing lighting requirements would
make their system commercially and technically infeasible. Highest Wind
asserted that AWES needs the development of new lights with half the
weight, size, and energy requirements of those available when FAA
published the Notice. Highest Wind also stated they planned to provide
an anti-collision light on the flying vehicle to make it conspicuous to
pilots in all weather conditions and expressed that marking the tether
would be very difficult to achieve. From a testing perspective, Highest
Wind desired to test in areas free of aviation then re-visit the
marking and lighting requirement.
Makani commented they intended to paint the wing white, in a manner
similar to wind turbine blades, and
[[Page 78852]]
proposed an option of adding light-emitting diode (LED) lights to the
wing tips similar to those used on light aircraft. Makani explained
that tether marking encumbers the tether and endangers the system
during launching and landing. Therefore, Makani proposed to not mark or
light the tether and instead mark the wing and ground station. Makani
commented their prototype, at the time FAA published in its Notice,
could not comply with current part 77 lighting requirements due to the
mass and drag of the lights. However, Makani anticipated the
utilization of lighting onboard the aloft portion that flashes at the
top and bottom of each loop, emulating the appearance of a stationary
radio tower and making the obstacle conspicuous to pilots. In an AWES
farm setting, Makani proposed to light the wings in the manner of a
traditional wind farm, with lights on the wings at the perimeter of the
farm and on wings that are high spots.
SkySails said they could partly comply with marking and lighting
requirements but did not provide any specific information. SkySails
stated their system will be conspicuous to the flying public with the
canopy made of yellow-colored fabric illuminated between sunset and
sunrise at the center and wingtips by a spotlight situated on top of
the control pod (suspended below the canopy). SkySails commented that
if the illumination of the kites and registration in air traffic charts
is not sufficient, wind farm arrays could be marked by tethered
balloons placed on the outlines of the array. Balloons and mooring
lines of the balloons will be marked and lighted according to existing
requirements. SkySails did not comment on the policy, other than to
provide specifics on their system.
Windlift commented they are fully committed to working with FAA and
NAS users to ensure aviation safety during the development of their
systems but did not specifically comment on the policy. Windlift
commented that their fabric wings can have bright colors embedded with
reflective elements to maximize visibility. During night operations,
Windlift's proposed system planned to use a conductive cable strung
with the tether or a battery to power lights. Windlift commented that
tether marking is a challenge to system performance due to increased
drag and placing multiple flags within 75 feet of the aloft portion
could provide a visual signal of the tether for pilots. Windlift
proposed the use of LED lights instead of lights with more weight.
V. Additional Discussion
A 2021 Department of Energy (DOE) report discusses U.S. locations
where there is an increase in average wind speed with altitude up to
approximately 300 meters (985 feet), above which the wind speed profile
becomes mostly flat up to 500 meters (1640 feet).\8\ DOE finds that
most AWES will operate below 500 meters. Aloft portions of an AWES,
including the tether or similar device connecting it to a ground
station, above 499 feet AGL would be in airspace available to general
aviation and must be readily identifiable so a pilot can see and avoid
it. As part of FAA's aeronautical study conducted under part 77 and the
process defined in FAA Order JO 7400.2, FAA may include marking and
lighting recommendations in its determination.
---------------------------------------------------------------------------
\8\ <a href="http://www.energy.gov/sites/default/files/2021-12/report-to-congress-challenges-opportunities-airborne-wind-energy-united-states.pdf">www.energy.gov/sites/default/files/2021-12/report-to-congress-challenges-opportunities-airborne-wind-energy-united-states.pdf</a>.
---------------------------------------------------------------------------
Advisory Circular 70/7460-1 describes the FAA's standards for
marking and lighting structures to promote aviation safety. Based on
individual AWES characteristics, FAA may require marking and lighting
applicable to specific systems to ensure visibility during varying
weather conditions or night operations. FAA continues to research and
test alternative marking and lighting for use by all components of an
AWES (to include the aloft portion and the tether or similar device).
Once the FAA identifies an acceptable standard, it may include it in AC
70/7460-1. Additionally, FAA must evaluate each AWES and issue a
technical note approving the system's marking and lighting prior to a
proposed AWES deployment and part 77 analysis.
As part of the part 77 evaluation, FAA will coordinate the proposal
with potentially impacted air traffic control (ATC) facilities for
local analysis, as required. If FAA determines the need for local
coordination, each affected facility performs an operational safety
analysis of the potential effects or risks of AWES operations to local
air traffic. This analysis may also include AWES-specific
considerations, e.g., the aloft portion separating from the ground
station or the duration required to recover the aloft portion to the
ground station. If the local ATC facility discovers additional safety
hazards, FAA may convene a local Safety Risk Management (SRM) panel to
complete a safety analysis and document its findings in an SRM
document. The SRM panel's findings could affect FAA's final
determination. Additionally, FAA-issued final determinations for AWES
proposals may include conditions for marking and lighting to ensure the
structure is visible to aircraft operating in proximity to an AWES.
VI. Final Policy
Based on feedback received in response to the Notice, the FAA
concludes that AWES may affect navigable airspace. As of the effective
date of this policy statement, the FAA amends the policy set forth in
the Notice and will consider part 77 applications for all AWES,
including permanent and operational systems. Those entities proposing
construction of an AWES that exceeds the parameters in section 77.9
(e.g., an AWES constructed at more than 200 feet AGL at its site) must
file advance notice with FAA.
FAA receipt of part 77 notices of proposed construction from all
AWES will enable the continued development of this emerging technology
while allowing FAA to study the potential impacts of each individually
proposed AWES on the safety and integrity of the NAS. Further, this
action ensures inclusion of AWES information in the FAA's publicly
searchable obstruction database.\9\
---------------------------------------------------------------------------
\9\ <a href="https://oeaaa.faa.gov/">https://oeaaa.faa.gov/</a>.
Issued in Washington, DC, on December 20, 2022.
Michael R. Beckles,
Director (A), Policy, AJV-P.
[FR Doc. 2022-27993 Filed 12-22-22; 8:45 am]
BILLING CODE 4910-13-P
</pre><script data-cfasync="false" src="/cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script></body>
</html>Indexed from Federal Register on December 23, 2022.
This is legal information, not legal advice. Laws vary by jurisdiction and change frequently. Always verify current law with official sources and consult a licensed attorney in your jurisdiction for advice on your specific situation.