What happened
On 2 April 2011, a Piper PA-31-300 Navajo Chieftain, registration N678BY, was conducting a private flight from Ft Lauderdale Executive Airport, Florida, to Providenciales Airport in the Turks and Caicos Islands. The flight, carrying one pilot and five passengers, proceeded normally until the aircraft was 5 nm from the destination runway. During the final approach, the pilot attempted to deploy the landing gear but found that the green DOWN LOCKED lights failed to illuminate, while the red NOT LOCKED light remained active.
After an unsuccessful attempt to use the manual extension handle while in a holding pattern, air traffic control instructed the pilot to divert to JAGS McCartney International Airport on Grand Turk. The pilot briefed the passengers for a potential gear-up landing. Upon arrival at the diversion airport, the pilot performed a low pass for visual confirmation by the tower controller, which confirmed the gear was still partially extended.
During the landing on Runway 11, the aircraft touched down on the left main gear and subsequently settled onto the right wingtip. During the rollout, the left main landing gear retracted, causing the aircraft to veer 90 degrees before stopping halfway down the runway. There were no injuries to the occupants, though the aircraft sustained damage to the flaps, propellers, right wingtip, and landing gear doors.
The investigation
Investigators examined the aircraft following the incident to determine why the landing gear failed to deploy. The inspection revealed that a hydraulic hose connected to the actuator for the right main landing gear door had failed. This failure caused a significant leak of hydraulic fluid from the system. This loss of pressure was the reason the emergency hand-pumped extension system was unable to function effectively.