The FAA has proposed an airworthiness directive (AD) that adds steps to procedures mandated in an existing AD for inspecting seat rails and components on certain Cessna 150, 152, 170, 172, 175, 177, 180, 182, 185, 188, 190, 195, 206, 207, 210, T303, 336, and 337 series airplanes.
The FAA made the proposal, which would retain all inspection and repair actions required by the AD to be superseded, “to prevent seat slippage or the seat roller housing from departing the seat rail, which may consequently cause the pilot/copilot to be unable to reach all the controls,” leading to possible loss of control.
The current AD, which became effective as amended on Sept. 24, 1990, requires “repetitive inspections and replacement of parts if necessary of the seat rail and seat rail holes; seat pin engagement; seat rollers, washers, and axle bolts or bushings; wall thickness of roller housing and the tang; and lock pin springs” on affected aircraft.
The FAA said it had in the last 20 years “received several reports of accidents, some fatal, for Cessna airplanes where the primary latch pin for the pilot/copilot seat is not properly engaged in the seat rail/track.” There had also been reported incidents of seat roller housings departing the seat rail.
“Consequently, we have added steps to the inspection procedures, added revised figures, and clarified some of the existing steps. This condition, if not corrected, could result in seat slippage or the seat roller housing departing from the seat rail, which may consequently cause the pilot/copilot to be unable to reach all the controls. This failure could lead to the pilot/copilot losing control of the airplane.” The added steps and clarifications are detailed and diagrammed in the draft AD.
The FAA estimates that the proposed AD will affect approximately 36,000 U.S.-registered airplanes, at a cost of $85 per aircraft for the required inspections. Costs of any needed part replacements could amount to $775 per aircraft, but would depend on the individual inspection results, the FAA said.
Comments can be submitted (Docket No. FAA-2010-1101) until Dec. 23.