Communiqués

TSB # A 10/2000

(Hull, Quebec, 20 July 2000) - What started out as a standard spin training exercise with a student pilot and instructor turned into a fatal crash when the rudder of the Laurentide Aviation Cessna 152 stuck over hard left. The final report by the Transportation Safety Board of Canada (TSB) concluded that improper maintenance procedures that released the aircraft for flight in an unsafe condition, a missing rudder cable return spring, and a design anomaly in the rudder stop mechanism contributed to the accident.

The Board has made four aviation safety recommendations that it believes will reduce or eliminate the possibility of this type of accident recurring.

Cessna Aircraft Company has developed a Service Bulletin designed to prevent over-travel of the rudder. The Board is concerned that, since the proposed Service Bulletin will be voluntary, not all Canadian-registered Cessna 150s and 152s will be modified and has recommended that:

• The Department of Transport issue an Airworthiness Directive to all Canadian owners and operators of Cessna 150 and 152 aircraft addressing a mandatory retrofit design change of the rudder horn stop bolt system to preclude over-travel and jamming of the rudder following a full rudder input.[A00-09]

Any mandatory airworthiness actions to retrofit Cessna 150 and 152 aircraft with newly designed rudder horn stop bolt systems will likely take considerable time to complete. In the meantime, these aircraft will be flying with a known safety deficiency. The Board believes that the circumstances of this accident suggest that the serious implications of the broken or missing rudder cable return spring were not fully understood. In fact, the possibility of an irreversibly jammed rudder during intentional spin entry by full rudder deflection was not understood until this accident investigation was completed has led the Board to recommend that:

• The Department of Transport, in conjunction with the Federal Aviation Administration, take steps to have all operators of Cessna 150 and 152 aircraft notified about the circumstances and findings of this accident investigation and the need to restrict spin operations until airworthiness action is taken to prevent rudder jamming.[A00-10]

The required logbook entries regarding the maintenance performed on the rudder system were not made, and it was evident that the operator, in general, did not maintain the aircraft journey logbooks in accordance with the Canadian Aviation Regulations (CARs). The Board has therefore recommended that:

• The Department of Transport take steps to ensure that operators and maintenance personnel are aware, in the interests of safety, of the importance of proper maintenance of aircraft journey logbooks and are aware of their responsibilities in this regard.[A00-11]

The Federal Aviation Administration in the United States is the regulatory body in the state of design and manufacture and has primary responsibilities with regard to continuing airworthiness of both the Cessna 150 and 152 aircraft. The Board has therefore recommended that:

• The National Transportation Safety Board review the circumstances and findings of this investigation and evaluate the need for mandatory airworthiness action by the Federal Aviation Administration.[A00-12]

The flight instructor and a student took off on a local training flight from runway 25 at Montréal/Les Cèdres Aerodrome, Quebec, at about 0850 eastern daylight time. The student pilot was practicing spins and recoveries. The student initiated a spin to the left, his sixth of the day, at an altitude of 3 600 feet above sea level. The first five spins were to the right. The aircraft entered the spin normally. After one and a half turns, the flight instructor asked the student to recover. The student applied pressure on the right rudder pedal, as taught by the flight instructor, and the rotation did not stop. The flight instructor took over the controls and applied pressure on the right rudder pedal to stop the rotation, but the rotation did not stop.

The aircraft, by then, was established in a stabilized spin, rotating to the left, and continuing its descent. The flight instructor applied full power for a moment, then full flaps, to no avail. Throughout the recovery attempt, the flight instructor continued in his efforts to avoid the crash. The aircraft struck the surface of Lac Saint-François. The student pilot sustained serious injuries but managed to evacuate the sinking aircraft through the right, rear window. He then tried to pull out the unconscious flight instructor, but without success. A fisherman close to the scene rescued the student and transported him ashore where emergency vehicles were standing by, but the flight instructor did not evacuate the aircraft and died in the accident.

The Transportation Safety Board of Canada is an independent agency operating under its own Act of Parliament. Its sole aim is the advancement of transportation safety. It is not the function of the Board to assign fault or determine civil of criminal liability.

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