Cessna C152 crash at Moisselles aerodrome

Flight and crash sequence On Sunday, 8 January 2012, at 17:04 local time, a Cessna C152 registered F-GLPO departed from the unpaved runway 25 at Moisselles aerodrome for a local flight of about ten minutes. The pilot was accompanied by a passenger. Radar data showed the aircraft followed the mandatory exit route to the edge of the control zone, then turned back and returned along the same route at an altitude of about 1,400 ft. The pilot then began the approach for the right-hand downwind leg of runway 25. The last recorded position at 17:13 was on the crosswind leg at about 700 ft. The wreckage was found in a clear field about 1 nautical mile west of the aerodrome, near the last recorded position. Witnesses reported seeing the aircraft in straight flight with level wings suddenly pitch down rapidly. ## Wreckage and technical findings The complete wreckage was concentrated on a small area. Site and wreckage observations indicated the aircraft struck the ground with high energy and a significant nose-down attitude. Technical examinations of the airframe, elevator trim, and flight control chains did not reveal any anomaly that could have contributed to the accident. No evidence of a bird strike was found on the windscreen debris. ## Medical and pathologic findings Blood samples and autopsies of the pilot and passenger did not reveal any element that could explain the event. The pilot's injuries suggested he was in a flying posture with his heels on the floor. His right hand, in a grasping attitude, was consistent with a spasm on the elevator control wheel. ## Investigations and tests The Cessna and Reims Aviation 150/152 are equipped with two control wheels for pitch and roll. The wheels are linked behind the instrument panel by a set of tubes forming a 'Y'. In the cabin, the vertical branch of the 'Y' passes behind the instrument panel, between the rudder pedals. A set of chains and pulleys is present on the 'Y' to transmit roll commands. A ground simulation was conducted with a person of similar build to the passenger. The tests showed that it is possible for a person in the right seat to place the end of their left foot on the elevator control pulley while maintaining a natural and comfortable posture. Without applying high pressure, the passenger could easily put the elevator control pulley in the 'full pitch down' position without disturbing roll. Under the test conditions, it was not possible to counter this action by acting on the control wheel. Interviews with several instructors showed that most were not aware of the presence of this pulley near the rudder pedals. Cessna Aircraft Company, the type certificate holder, informed the BEA that no case of passenger interference with the control pulley had been reported to them. ## Conclusion The loss of pitch control occurred suddenly on the crosswind leg at about 700 ft, while the flight had been controlled up to that point. No technical anomaly was found. The investigation showed that it is possible for a passenger in the right seat to push the elevator control pulley with their left foot, causing a pitch-down action. Such an action is consistent with a natural and comfortable posture for a person of the passenger's size. The observations suggest that the pilot was probably applying pressure with both hands on the elevator control wheel at the time of the accident. This attitude is consistent with a pilot trying to counter a pitch-down action. It is therefore possible that the accident was due to an involuntary and undetected action by the passenger on the elevator control pulley. Given the low altitude of the aircraft in the circuit, the pilot was unable to regain control. The investigation did not establish whether the pilot had briefed the passenger before the flight. A briefing would have raised the passenger's awareness of the specific environment of the aircraft and reminded them of the importance of not interfering with the controls. ## Safety recommendations The BEA recommended that the Federal Aviation Administration ensure that Cessna Aircraft Company informs owners of Cessna and Reims Aviation 150/152 of the possibility for a passenger to cause a pitch-down action by inadvertently acting on the elevator control pulley located near the rudder pedals. The BEA also recommended that the European Aviation Safety Agency inform national civil aviation authorities of the potential risks on Cessna and Reims Aviation 150/152 for a passenger to cause a pitch-down action by inadvertently acting on the elevator control pulley located near the rudder pedals.