The Federal Aviation Administration has issued final display requirements for a Skyryse digital flight-control conversion of the Robinson R66 helicopter.
Skyryse proposes replacing the R66's mechanical primary controls with a fly-by-wire system called SkyOS. The special conditions take effect Sept. 11 and become part of the certification basis for this specific modification.
Mechanical pushrods normally give a pilot tactile feedback through the cyclic and collective. FAA says that feedback is absent when computers calculate the commanded control positions, creating a gap in rules written for mechanical systems.
The final conditions require the system's functions, controls, indications and alerts to minimize pilot errors and confusion. They also require a visible indication of the current mode and clearly grouped information under all expected lighting conditions.
The display must communicate commanded primary-control positions and relevant information about the fly-by-wire system's operating state. Degraded functions needed for continued safe flight and landing are included in the requirement.
FAA describes the R66 as a single-engine, normal-category helicopter with a maximum takeoff weight of 2,700 pounds and seating for up to five passengers. It is approved for one pilot and day or night flight under visual flight rules.
The agency received one general objection to its proposed special conditions, but the commenter offered no explanation or requested change. FAA adopted the conditions as proposed.
The action is not an approval of every operational claim for SkyOS or a rule for all helicopters. Skyryse still must show that the modified aircraft meets the applicable certification basis before the supplemental type certificate can be issued.