[Federal Register Volume 91, Number 154 (Wednesday, August 12, 2026)]
[Rules and Regulations]
[Pages 52002-52003]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2026-16412]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 27
[Docket No. FAA-2025-5245; Special Conditions No. 25-895-SC]
Special Conditions: Skyryse, Robinson Helicopter Company Model
R66 Helicopter; Flight Control System Annunciation of Control
AGENCY: Federal Aviation Administration (FAA), DOT.
ACTION: Final special conditions.
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SUMMARY: These special conditions are issued 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 regulations do not contain adequate or
appropriate safety standards for this design feature. These 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: Effective September 11, 2026.
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 Locust, Kansas City, MO 64106; telephone (816) 329-
4144; email [email protected].
SUPPLEMENTARY INFORMATION:
Background
On April 10, 2023, Skyryse applied for a supplemental type
certificate (STC) for replacing the current mechanical primary flight
controls with an FBW flight 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 Model R66 is a single pilot
helicopter approved for day and night operations under visual flight
rules (VFR) only.
Section 27.695 was issued in 1964 for rotorcraft with rudimentary
mechanical
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systems. The state of technology at that time provided no basis for a
digital replacement. Skyryse is proposing to replace the current
mechanical primary flight controls on the Model R66 helicopter with a
digital FBW FCS. Because of the loss of pilot awareness that would have
been provided by mechanical system feedback to the cyclic, an
annunciation requirement is necessary through these special conditions.
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 (i.e., 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 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 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 would incorporate the following
novel or unusual design feature:
A primary FCS that replaces the mechanical cyclic and collective
with an FBW FCS. Skyryse applied for a supplemental type certificate
for a system with aircraft-agnostic flight automation technology, the
SkyOS, in Robinson Model R66 rotorcraft. The flight control inputs from
this FBW system will replace the tactical feedback from pushrods with a
position calculated by a computer. The SkyOS does not modify the
engine, main rotor, tail rotor, or physical travel limits of the flight
control surfaces.
Discussion
The 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.
The special conditions are required to address the gap in the
regulation that was created by the replacement of mechanical primary
flight control with digital controls. Section 27.695 is based on the
ability of the pilot to manage control of the rotorcraft with tactile
feedback, which does not exist in the proposed FBW design. As such, to
provide the same level of safety, these special conditions would
require a display of the commanded positions of the primary flight
controls and any information regarding the FBW system state of
operation.
The 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.
Discussion of Comments
The FAA issued Notice of Proposed Special Conditions No. 27-26-01-
SC for the Robinson Model R66 helicopter, which was published in the
Federal Register on April 21, 2026 (91 FR 21268). One commenter stated
general disagreement without explanation and without requesting a
change to the proposed special conditions.
The special conditions are adopted as proposed.
Applicability
As discussed above, these special conditions are applicable to the
Robinson Model R66 helicopter. Should Skyryse apply at a later date for
a supplemental type certificate to modify any other model included on
Type Certificate No. R00015LA to incorporate the same novel or unusual
design feature, these special conditions would apply to that model as
well.
Conclusion
This action affects only a certain novel or unusual design feature
on one helicopter model. 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, 44704.
The Special Conditions
Accordingly, pursuant to the authority delegated to me by the
Administrator, the following special conditions are issued as part of
the type certification basis for the Robinson Helicopter Company
(Robinson) Model R66 helicopter, as modified by Skyryse.
Flight Control Systems
The flight control system functions, controls, indications, and
alerts must be designed to minimize flightcrew errors and confusion
concerning operation of the flight control system. This includes any
degraded functions required for continued safe flight and landing.
Means must be provided to indicate the current mode of operation to the
pilot. The controls and indications must be grouped and presented to
the pilot in a format that clearly defines the flight control system
functions. The displayed information must be visible to the flightcrew
under all expected lighting conditions.
Issued in Fort Worth, Texas, on August 8, 2026.
Jorge R. Castillo,
Manager, Technical Policy Branch, Policy and Standards Division,
Aircraft Certification Service.
[FR Doc. 2026-16412 Filed 8-11-26; 8:45 am]
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