A set of FAA special conditions published on Friday in the Federal Register suggests Bell's 525 super-medium twin could be certified later this year, even though the company has officially remained non-committal. In the latest FAA Part 29 certification special condition proposed for the heavy-twin helicopter, the FAA noted, “Bell applied for multiple extensions, with the most recent occurring on November 12, 2020. The date of the updated type certification basis is December 31, 2016, based upon the applicant's proposed type certificate issuance date of December 31, 2021.”
This special condition addresses the current requirement that the pilot is able to determine that full control authority is available before flight. The FAA notes that this has traditionally been done via manipulating the mechanically linked flight controls before flight, but since the 525 four-axis fly-by-wire (FBW) has no such linkages, that type of verification is not possible. An “FBW system may have the ability to verify full control authority without having to move the primary flight controls,” the FAA said.
The proposed special condition would require Bell to demonstrate that “the rotorcraft must be shown by analysis, tests, or both, to be capable of continued safe flight and landing after” failures or jamming of the flight controls within the normal flight envelope “without requiring exceptional piloting skill or strength. Probable failures must have only minor effects.”
Bell officially launched the 19-passenger 525—the first civil helicopter to feature FBW flight controls—in 2012, primarily to serve the then-booming offshore energy market. Unveiled when the price of oil was $105 per barrel, in recent years the program has been slowed by various flight test delays—including a fatal crash of a flight test aircraft in 2016—and overall dimming market conditions driven by the collapse in global oil prices. AIN was able to verify that two of Bell's four 525 test aircraft flew last week.