What happened
A Douglas DC-9-82, operated by Rutas Aéreas De Venezuela, departed from La Chinita International Airport in Maracaibo for a scheduled commercial flight to Maiquetía. The aircraft was carrying 121 people, including two pilots, four cabin crew members, and 115 passengers.
During the initial climb and the retraction of the landing gear, the flight crew observed a light indication signaling that the nose gear had failed to transition and lock into the bay. Following established Quick Reference Handbook (QRH) procedures, the crew requested authorization from approach control to return to the departure airport. The aircraft landed safely at La Chinita International Airport at 12:15 UTC. All passengers and crew members were uninjured, though the aircraft experienced the aforementioned landing gear malfunction.
The investigation
The investigation involved a review of crew licenses, medical certificates, flight logs, and flight plans, as well as an audit of the operator's airworthiness and radio station certificates. Investigators also examined maintenance records from the certified maintenance organization responsible for recent scheduled services.
A physical inspection and photographic documentation of the aircraft were conducted. During the troubleshooting process, investigators identified that the nose gear strut was operating with low nitrogen levels. To rectify the issue, technicians replenished both the hydraulic oil and the nitrogen within the nose gear strut. Subsequent functional tests of the nose gear system yielded satisfactory results.
Findings
- The investigation determined that the loss of nitrogen in the nose gear strut occurred through the servicing valve.
- No leaks were detected at any other points in the system.
- Nitrogen leakage via the service valve was identified as the cause of the improper gear indication.