The FAA is proposing to require newly certified large transport-category airplanes be designed to withstand the loads caused by rapid reversals of the rudder pedals. The requirement would apply to Part 25 airplanes that have a powered rudder control surface or surfaces, which would include all but the smaller business jets.
The agency says this rule is necessary “because accident and incident data show that pilots sometimes make rudder reversals during flight, even though such reversals are unnecessary and discouraged by pilot training programs.” Current design standards do not require the airplane structure to withstand the loads that may result from such reversals, although the FAA concedes that these incidents are “low-probability events.”
If the airplane loads exceed those for which it is designed, “the airplane structure may fail, resulting in catastrophic loss of control of the airplane.” This proposal aims to prevent structural failure of the rudder and vertical stabilizer that may result from these rudder reversals. The agency estimates the cost of compliance by business jets without fly-by-wire rudder controls would be about $235,000 per aircraft. The cost would be “minimal” for aircraft with FBW rudder controls.
In 2016, the European Aviation Safety Agency (EASA) began applying “special conditions” to new airplane certification programs, mandating that manufacturers address the risk of rudder reversal and late last year proposed to adopt the special conditions into its Part 25 basic rules. The FAA says the requirements by EASA match those proposed in this NPRM. Comments are due by October 15.
