What happened
On the morning of December 12, 2002, an Airbus A300/B4, registration OO-DLT, operated by European Air Transport (EAT) for DHL, was parked at Lisbon International Airport for scheduled daily inspections. A maintenance team from Louro Aircraft Services (LAS) was performing the task after receiving a request to verify the part numbers of the nose gear up-locks.
To access the components, the team manually opened the nose gear compartment doors. After recording the necessary information, the team attempted to close the doors by pressurizing the aircraft's "green" hydraulic system. While the right-side door closed immediately, the left-side door failed to respond to the manual control lever.
Seeking to identify the cause of the malfunction, the team leader climbed a ladder and entered the nose gear bay to inspect the door actuators. During this inspection, the left-side door suddenly closed, trapping the technician between the two doors at the neck and upper chest level. Although colleagues immediately depressurized the hydraulic system to release him, the technician sustained severe internal injuries and multiple fractures to the ribs, spine, and upper limbs. He passed away three days later at a hospital in Lisbon.
The investigation
The GPIAAF investigation examined the mechanical operation of the nose gear door system and the maintenance procedures followed. Investigators performed a demonstration using a similar aircraft type to replicate the event. The tests confirmed that while the right door operated normally, the left door required multiple manual lever selections before responding.
The investigation also reviewed the maintenance company's procedures and the manufacturer's instructions. It was established that the technician did not consult the Aircraft Maintenance Manual (AMM) prior to the task and failed to follow the safety warnings posted near the manual operating levers.
Findings
- The primary cause of the accident was the malfunctioning nose gear door closing system, which caused the left door to fail to respond normally to the manual lever, creating the need for the technician to investigate the mechanism.
- The technician failed to follow recommended safety measures for manual door operation, specifically the requirement to use a safety pin to secure the handle in the "open" position.
- The technician did not follow the manufacturer's prescribed procedure for investigating a door failure, which includes setting the lever to "open," inserting a safety pin, and depressurizing the hydraulic system before inspection.
- The maintenance team did not consult the Aircraft Maintenance Manual (AMM) regarding the specific precautions for this operation.