[Federal Register Volume 91, Number 166 (Friday, August 28, 2026)]
[Proposed Rules]
[Pages 55501-55503]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-17661]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 27
[Docket No. FAA-2026-1585; Notice No. XX-XX-XX-SC]
Special Conditions: Skyryse, Robinson Helicopter Company Model
R66 Helicopter; Control Margin Awareness
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Notice of proposed special conditions.
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SUMMARY: This action proposes special conditions for the Robinson
Helicopter Company (Robinson) Model R66 helicopter. This helicopter, as
modified by Skyryse, will have a novel or unusual design feature when
compared to the state of technology envisioned in the airworthiness
standards for normal category helicopters. This design feature replaces
the mechanical flight controls with a digital fly-by-wire FBW system.
The applicable airworthiness
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regulations do not contain adequate or appropriate safety standards for
this design feature. These proposed special conditions contain the
additional safety standards that the Administrator considers necessary
to establish a level of safety equivalent to that established by the
existing airworthiness standards.
DATES: Send comments on or before October 13, 2026.
ADDRESSES: Send comments identified by Docket No. FAA-2026-1585 using
any of the following methods:
Federal eRegulations Portal: Go to www.regulations.gov and follow
the online instructions for sending your comments electronically.
Mail: Send comments to Docket Operations, M-30, U.S. Department of
Transportation (DOT), 1200 New Jersey Avenue SE, Room W12-140, West
Building Ground Floor, Washington, DC 20590-0001.
Hand Delivery or Courier: Take comments to Docket Operations in
Room W12-140 of the West Building Ground Floor at 1200 New Jersey
Avenue SE, Washington, DC, between 9 a.m. and 5 p.m., Monday through
Friday, except Federal holidays.
Fax: Fax comments to Docket Operations at 202-493-2251.
Docket: Background documents or comments received may be read at
www.regulations.gov at any time. Follow the online instructions for
accessing the docket or go to Docket Operations in Room W12-140 of the
West Building Ground Floor at 1200 New Jersey Avenue SE, Washington,
DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal
holidays.
FOR FURTHER INFORMATION CONTACT: Johannes vanHoudt, Product Policy
Management, AIR-62B, Technical Policy Branch, Policy and Standards
Division, Aircraft Certification Service, Federal Aviation
Administration, 901 Locus St., Kansas City, MO 64106; telephone (819)
329-4144; email [email protected].
SUPPLEMENTARY INFORMATION:
Comments Invited
The FAA invites interested people to take part in this rulemaking
by sending written comments, data, or views. The most helpful comments
reference a specific portion of the proposed special conditions,
explain the reason for any recommended change, and include supporting
data.
The FAA will consider all comments received by the closing date for
comments, and will consider comments filed late if it is possible to do
so without incurring delay. The FAA may change these special conditions
based on the comments received.
Privacy
Except for Confidential Business Information (CBI) as described in
the following paragraph, and other information as described in title
14, Code of Federal Regulations (14 CFR) 11.35, the FAA will post all
comments received without change to www.regulations.gov, including any
personal information you provide. The FAA will also post a report
summarizing each substantive verbal contact received about these
special conditions.
Confidential Business Information
Confidential Business Information (CBI) is commercial or financial
information that is both customarily and actually treated as private by
its owner. Under the Freedom of Information Act (FOIA) (5 U.S.C. 552),
CBI is exempt from public disclosure. If your comments responsive to
these special conditions contain commercial or financial information
that is customarily treated as private, that you actually treat as
private, and that is relevant or responsive to these special
conditions, it is important that you clearly designate the submitted
comments as CBI. Please mark each page of your submission containing
CBI as ``PROPIN.'' The FAA will treat such marked submissions as
confidential under the FOIA, and the indicated comments will not be
placed in the public docket of these proposed special conditions. Send
submissions containing CBI to the individual listed in the FOR FURTHER
INFORMATION CONTACT section above. Comments the FAA receives, which are
not specifically designated as CBI, will be placed in the public docket
for these proposed special conditions.
Background
On April 10, 2023, Skyryse applied for a supplemental type
certificate (STC) for installing its SkyOS fly-by-wire (FBW) fight
control system (FCS) in the Robinson Model R66 helicopter. The Robinson
Model R66 helicopter, currently approved under Type Certificate No.
R00015LA, is a single-engine, normal category rotorcraft with a maximum
takeoff weight of 2,700 pounds and a maximum seating capacity of five
passengers.
The current 14 CFR part 27 regulations do not contain adequate
standards for FBW FCS with respect to control margin awareness. The
airworthiness standards for controllability and maneuverability of the
rotorcraft are contained in Sec. 27.143. These controllability
requirements are compatible with most FBW systems, while most of the
maneuverability requirements are not affected by FBW systems, except
for the control margins. One of the purposes of the rule is to ensure
that control margins (at the rotor and the anti-torque system level)
are sufficient in the defined flight envelope to avoid loss of control
(that is, the rotorcraft has adequate control power for the pilot to
exit potentially hazardous flight conditions). Implicit in this purpose
is that the pilot is provided with sufficient awareness of proximity to
control limits. Because Sec. 27.143 was written to address hydro-
mechanical flight control systems, through which pilot awareness of
control margins is provided by cyclic and pedal position relative to
cockpit control stops, the rule is inadequate for certification of a
FBW FCS, where there is no mechanical link between the inceptor and the
receptor. Without a constant correlation between cockpit control and
main or tail rotor actuator positions, the FCS may not provide tactile
control margin feedback to the pilot through cockpit control position
relative to the control position physical stop or limit, for all flight
conditions. The special conditions will require the minimum safety
standard to ensure awareness of proximity to control limits at the main
rotor and tail rotor is provided to pilots of the helicopter.
Type Certification Basis
Under the provisions of 14 CFR 21.101, Skyryse must show that the
Robinson Model R66 helicopter, as changed, continues to meet the
applicable provisions of the regulations incorporated by reference in
Type Certificate No. R00015LA or the applicable regulations in effect
on the date of application for the change.
If the Administrator finds that the applicable airworthiness
regulations (e.g., 14 CFR part 27) do not contain adequate or
appropriate safety standards for the Robinson Model R66 helicopter
because of a novel or unusual design feature, special conditions are
prescribed under the provisions of Sec. 21.16.
Special conditions are initially applicable to the model for which
they are issued. Should the applicant apply for an STC to modify any
other model included on the same type certificate to incorporate the
same novel or unusual design feature, these special conditions would
also apply to the other model under Sec. 21.101.
In addition to the applicable airworthiness regulations and special
conditions, the Robinson Model R66
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helicopter must comply with the fuel-vent and exhaust-emission
requirements of 14 CFR part 34, and the noise-certification
requirements of 14 CFR part 36.
The FAA issues special conditions, as defined in 14 CFR 11.19, in
accordance with title 14, Code of Federal Regulations (14 CFR) Sec.
11.38, and they become part of the type certification basis under Sec.
21.101.
Novel or Unusual Design Features
The Robinson Model R66 helicopter will incorporate the following
novel or unusual design feature:
A primary FCS that replaces the primary mechanical flight controls
with a fully authority digital FBW system. The flight control inputs
from this FBW system will replace the tactical feedback from pushrods
with a position calculated by a computer.
Discussion
These special conditions require the minimum safety standard to
ensure awareness of proximity to control limits at the main rotor and
tail rotor is provided to pilots of the Robinson Model R66 helicopter.
The system design must provide the pilot with sufficient awareness of
proximity to control limits, traditionally achieved through
conventional flight controls by the pilot's inherent awareness of
cyclic stick and pedal position relative to control stops.
Applicability
As discussed above, these proposed special conditions are
applicable to the model for which they are issued. Should the applicant
apply for an STC to modify any other model included on the same type
certificate to incorporate the same novel or unusual design features,
these special conditions would apply to the other model as well.
Conclusion
This action affects only certain novel or unusual design features
on one model of helicopter. It is not a rule of general applicability
and affects only the applicant who applied to the FAA for approval of
these features on the helicopter.
List of Subjects in 14 CFR Part 27
Aircraft, Aviation safety, Reporting and recordkeeping
requirements.
Authority Citation
The authority citation for these special conditions is as follows:
Authority: 49 U.S.C. 106(f), 40113, 44701, 44702, and 44704.
The Proposed Special Conditions
Accordingly, the Federal Aviation Administration (FAA) proposes the
following special conditions as part of the type certification basis
for Robinson Helicopter Company Model R66 helicopters, as modified by
Skyryse.
In addition to the existing Sec. 27.143 requirements, the
following special condition applies: The system design must ensure that
the flight crew is made suitably aware whenever the means of primary
flight control approaches the limits of control authority. For the
context of this special condition, the term ``suitable'' indicates an
appropriate balance between nuisance and necessary operation.
Issued in Fort Worth, Texas, on August 26, 2026.
Jorge R. Castillo,
Manager, Technical Policy Branch, Policy and Standards Division,
Aircraft Certification Service.
[FR Doc. 2026-17661 Filed 8-27-26; 8:45 am]
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