What happened
On May 14, 1973, a Cessna 150 (registration HB-CUV) was conducting a private flight training session at Lausanne-La Blécherette Airport. The flight was led by a student pilot, who had recently begun solo operations. After an initial approach that required a go-around due to runway occupancy by another aircraft, the student attempted a second landing on runway 19.
During the landing flare, the aircraft touched down in a nose-high attitude. As the plane crossed an uneven section of the runway, it bounced approximately 50 cm into the air. The pilot released back-pressure on the control column, causing the aircraft to hit the ground heavily and bounce again. Despite radio instructions from the instructor, who was monitoring the flight from the runway edge, the student pilot responded to each subsequent bounce by pushing the control column forward. After three or four bounces, the nose gear collapsed, and the aircraft came to a stop 150 meters past the runway threshold. The student pilot sustained no injuries.
The investigation
The investigation confirmed that the student pilot held a valid student pilot certificate and had passed the necessary theoretical examinations. The instructor was also fully licensed. The Cessna 150 was found to be in a valid state of airworthiness, with the weight and center of gravity within prescribed limits. Meteorological conditions were favorable, with visibility of 10 km and light winds.
Investigators examined the runway surface and noted that longitudinal irregularities in the runway profile frequently caused aircraft to bounce even during otherwise correct landings. The investigation also reviewed the pilot's actions and the instructor's radio communications during the incident.
Findings
- The primary cause of the accident was the inadequate use of the elevator following the initial bounce.
- The student pilot's reaction—pushing the control column forward after each bounce—was an instinctive but incorrect response to the aircraft's behavior.
- The student pilot lacked the necessary proficiency to manage the aircraft's aerodynamic state during a bounce, specifically failing to maintain sufficient back-pressure or execute a go-around.
- The structural failure of the nose gear and engine mount was a direct result of the repeated heavy impacts caused by the uncontrolled bouncing.