22 March 2007
The US National Transportation Safety Board is calling for the FAA to issue an AD (airworthiness directive) on Cessna 150 and 152 aircraft, following a crash in 2005 near Williamsburg in Ohio. Both pilots were killed.
<a href=’http://www.ntsb.gov/ntsb/brief2.asp?ev_id=20050414X00457&ntsbno=NYC05FA069&akey=1′ target=’_blank’>Investigators found</a> that the aircraft’s rudder had jammed beyond its normal ambit of travel, apparently because two rudder bumpers had been installed inverted, and that the right bumper had travelled beyond the rudder stop and had become stuck beyond it. It is likely that the pilots had been carrying out spin training and that, with a jammed rudder, the aircraft had made an ‘uncontrolled descent into terrain’.
According to the initial report, “the investigation could not determine if the rudder bumpers were inverted at the time of production, or if they had been inverted during the maintenance history of the airplane. The airplane manufacturer issued a service bulletin about 3 1/2 years prior to the accident. The purpose of the service bulletin was to provide an enhanced rudder stop, bumper, doubler and attachment hardware designed to assist in preventing the possibility of the rudder overriding the stop bolt during full left or right operation of the rudder. Specifically, the new rudder stop was much larger than the original rudder stop. The service bulletin had not been complied with on the accident airplane, and under 14 CFR Part 91, was not required.”
The Service Bulletin in question is Cessna Service Bulletin No. SEB01-1.
The NTSB has said that the FAA should make the Service Bulletin mandatory at the next 100 hour check or annual inspection, to ensure the bumpers are correctly installed. Even if it doesn’t become an AD, it might be worth a quick check
