What happened
On 10 January 1998, a Mooney M20E, registration G-ASUB, was conducting practice circuits at North Coates Airfield, Lincolnshire. The aircraft had recently undergone engine work during a three-month period of being out of service, prompting the pilot to perform practice landings and glide approaches.
During the fifth circuit, the pilot intentionally maintained a high altitude on final approach, intending to lower the landing gear later to increase drag and steepen the descent. While on short finals, the pilot selected the landing gear down and locked. Following a radio communication from another aircraft, the pilot further adjusted the approach by deploying the first and second stages of flaps and performing a left sideslip to manage the excess height.
Although the initial touchdown was positive, the aircraft experienced a slight bounce. Upon the subsequent touchdown, a loud scraping noise was heard. The pilot initially applied power but quickly closed the throttle upon realizing the landing gear was not extended. The aircraft subsequently slid along the runway, coming to a halt approximately halfway down the strip. The incident resulted in damage to the propeller and lower fuselage, with no injuries reported.
The investigation
Investigators examined the aircraft's landing gear mechanism and the cockpit environment. The landing gear on this model is manually retracted using a lever that moves through 90 degrees, assisted by springs. The investigation established that the landing gear retraction lever was found in an unlocked position, near the up and locked position.
An eyewitness observed the aircraft bounce slightly after the initial contact, at which point the landing gear retracted. The investigation also noted that while an unlocked gear illuminates a red warning light and arms the gear warning horn, the horn is positioned behind the co-pilot's control panel. This placement makes the warning horn difficult to hear when the engine is running and the pilot is wearing a headset.
Findings
- The landing gear retracted following a slight bounce during the landing phase.
- The landing gear lever was found in an unlocked state, close to the retracted position.
- The landing gear retraction lever was left in an unlocked position, allowing the gear to move.
- The gear warning horn was not effectively audible to the pilot due to its location and the use of headsets during engine operation.