Move Tied To An Accident Which Occurred In 2009

Following the investigation into an accident which occurred on January 27th, 2009, in which an ATR 42 went down on final approach to Lubbock, TX in icing conditions, the NTSB determined that the stall-prevention system on the airplane was a contributing factor to the accident. The board also cited poor airspeed management on the part of the pilots of the cargo flight, both of whom survived the accident.

Flight Global reports that the letter sent by the NTSB to both regulatory agencies points out that the stall prevention system in the ATR-42 did not require a stick pusher function for certification of the airplane, the board "has long recognized that the certification standards do not capture real-world icing conditions."

The Board has recommended to both the FAA and EASA that they require that Avions de Transport Régional (ATR) 42-series airplanes operating in the United States incorporate a revised stickpusher activation angle of attack (AOA), such that the stick pusher activates before the stall AOA in the presence of airframe ice accretions.

It goes on to recommend that all U.S.- and European-certificated transport-category airplanes equipped with stick pushers be evaluated to ensure that the stick pusher activates at an angle of attack that will provide adequate stall protection in the presence of airframe ice accretions. (ATR-42 photo from file)

FMI: www.ntsb.gov