Synopsis
On 16 June 2019, a Cessna F177RG Cardinal RG, registration G-AYSY, experienced a landing gear malfunction during a private flight from Leicester Airport. The pilot was unable to confirm the landing gear was locked down and subsequently landed on a grass runway, where the gear retracted and the aircraft sustained damage to the propeller and fuselage. The pilot suffered minor injuries.
History of the Flight
The aircraft departed Leicester Airport for a short flight to Sywell Aerodrome. After departure, the pilot noted that the landing gear retracted slower than normal. Upon arrival at Sywell, the pilot selected gear down but saw neither the green (down and locked) nor red (up) indicator lights. After a go-around, he attempted manual extension using the emergency hand pump, which provided no resistance. He decided to return to Leicester, where he was familiar with the smooth grass strip. A low pass confirmed the gear was hanging but not locked. He then approached Runway 16, shut down the engine at about 100 ft, and landed. The touchdown was smooth, but the exhaust and propeller dug into the ground, bringing the aircraft to an abrupt stop.
Aircraft Examination
Post-accident inspection at a maintenance facility revealed that the hydraulic landing gear-up pressure line had separated from its fitting. The aluminium pipe, using flare fittings, had failed at the flare joint. The hydraulic fluid had escaped, preventing the gear from locking. The aircraft had recently undergone maintenance for a loss of hydraulic system pressure; an internal power pack leak had been repaired and the system tested successfully 18 times before the accident flight.
Analysis
The separation of the landing gear-up pressure line resulted in total loss of hydraulic fluid, which prevented the landing gear from locking down. Aluminium pipes with flare fittings can be weakened by overtightening, repeated movement, or age. The pilot's decision to land on a familiar grass strip and engine shutdown mitigated further damage.