What happened
On 13 April 2004, a Fournier RF4D, registration G-AWLZ, was performing a private flight in Gloucestershire. The pilot was returning to Nympsfield after a local flight conducted in favorable weather conditions. During the downwind leg of the approach, the pilot performed the necessary checks and manually extended the single central landing wheel, verifying that the gear was in the down and locked position.
Although the touchdown itself was smooth, the landing gear failed to support the aircraft. This caused the fuselage to make contact with the ground, resulting in substantial damage to the propeller, scraping along the fuselage, and potential shock loading to the engine. There were no injuries to the pilot.
The investigation
Investigators examined the manual retraction mechanism, which utilizes a hand-operated lever connected to a cross tube. The system relies on a latch that engages automatically when the gear reaches the fully extended or retracted position.
Post-accident inspections by a maintenance organization revealed a crack at the base of the landing gear lever. While the final fracture was recent, evidence suggested the crack was an old defect that had been progressing over time. It was determined that when the pilot operated the lever, the component moved without actually extending the gear or engaging the downlock latch.
Furthermore, the investigation found that the landing gear downstop—a wooden strip located at the rear of the wheel bay—had become crushed and saturated with oil. This degradation allowed the gear to travel past the point where the downlock latch could properly secure the assembly. The investigation also noted that the lever's location makes it difficult to reach, sometimes leading pilots to use their feet to move it, which can exert excessive force on the mechanism. The difficulty in inspecting the fracture area likely contributed to the defect remaining undetected.