What happened
On 15 September 2006, a Cessna 152 Aerobat, registration G-FLAP, was conducting a training flight at Sandtoft Airfield in Lincolnshire. The flight was being led by an instructor accompanied by a student preparing for their first solo flight. The aircraft was operating on Runway 05 Left, with surface winds recorded at 10 to 15 knots from 360 degrees.
During the final approach, the aircraft encountered bumpy conditions at an altitude of approximately 10 feet. The instructor noted that the aircraft's aiming point was roughly 215 meters beyond the touchdown threshold. In an attempt to correct the approach path, the instructor reduced power to increase the descent rate while maintaining a target airspeed of 65 knots. During this maneuver, the aircraft encountered a sudden downdraft. This caused the aircraft to descend rapidly, leading the nosewheel to strike a barbed wire fence in the runway undershoot area. The impact partially arrested the aircraft's movement and resulted in a very firm touchdown on the runway in a nose-down attitude.
The investigation
The investigation examined the mechanical state of the aircraft and the local environmental conditions. There was no evidence of any pre-existing mechanical defects in G-FLAP that contributed to the event. The investigators also looked into the possibility of localized wind disturbances. It was noted that while buildings and undulating terrain near an airfield can create turbulence or downdrafts, the official Aeronautical Information Package (AIP) for Sandtoft did not contain specific warnings regarding unusual surface wind conditions at that location. The instructor suggested the downdraft was likely caused by the disturbance of airflow over industrial units situated to the north and northwest of the airfield.
Findings
- The aircraft sustained significant damage, including a collapsed nose landing gear, a damaged propeller, engine damage, and damage to the left main landing gear and fuselage structure.
- The nose landing gear collapse was triggered by the aircraft striking a barbed wire fence and the subsequent heavy impact on the runway.
- The primary contributing factor was the encounter with a downdraft during the final approach.
- There were no injuries to the two occupants, and no fire occurred following the impact.