History of the Flight
On 20 June 2010, a Piper PA 34-200T aircraft, registered PK-SUV, operated by PT. Alfa Trans Dirgantara as a charter flight, departed Halim Perdanakusuma Airport at 0731 LT (0031 UTC) for Ahmad Yani Airport, Semarang. On board were one pilot and three passengers (a company pilot, engineer, and mechanic).
During final approach to runway 13 at Semarang, the landing gear was selected down. The main landing gears extended and locked, but the nose landing gear did not extend. The pilot executed a go-around and held on the left downwind for runway 13.
Attempted Gear Extension
While holding, the pilot attempted to extend the nose landing gear manually using the free-fall control, but the nose gear remained retracted. The pilot then decided to return to Halim Perdanakusuma.
At 0401 UTC, the aircraft flew overhead Halim Perdanakusuma Airport. The pilot requested the tower to visually check the landing gear; the tower confirmed that only the two main landing gears were extended. Following a second overflight, the pilot decided to land on the grass strip adjacent to runway 06.
Landing and Damage
Prior to touchdown, both engines were shut down and the propellers feathered. The aircraft landed on the grass strip and rolled approximately 100 meters. The nose section sustained damage, and the left engine propeller blades were bent. The pilot and three passengers disembarked normally without injuries.
Investigation
The investigation revealed that the nose landing gear failed to extend due to a blockage in the hydraulic system. Dirt was found on the hydraulic line between the restrictor and the actuator of the nose landing gear, and the hydraulic restrictor had a diameter of 0.31. The National Transportation Safety Committee (NTSC) determined that the hydraulic system had not been properly maintained to ensure cleanliness for safe operation.
Findings and Recommendations
The NTSC found that the aircraft was intact except for the nose damage and bent propeller blades. No other damage was observed. The pilot held a valid Commercial Pilot License and was current on the aircraft type. The investigation concluded that the nose landing gear malfunction was caused by contamination in the hydraulic system. The NTSC recommended that PT. Alfa Trans Dirgantara assure the aircraft hydraulic system is properly checked and maintained clean for safe operation.