What happened
On May 24, 2015, a Bombardier DHC-8-400 operated by PLL LOT departed from Wrocław (WRO) for a scheduled flight. Shortly after takeoff, the flight crew discovered that the landing gear could not be retracted. In accordance with the established checklist for an "ALL LDG GEAR FAIL TO RETRACT" scenario, the crew executed the necessary procedures and decided to return to Wrocław.
Upon landing at Warsaw Chopin Airport (EPWR), a subsequent inspection revealed that the cover for the emergency landing gear release system, located on the cockpit ceiling panel, was not properly closed. This unlatched cover had caused the landing gear control system to be inhibited. Once the pilots secured the cover latch, the system returned to normal operational status.
The investigation
The PKBWL investigation focused on the mechanical state of the cockpit panel and the operational procedures followed by the crew. The investigation established that the opening of this specific cover is a standard part of the cockpit preparation checklist performed during the pre-flight phase following overnight parking. The investigators examined whether the failure was due to improper handling during this procedure or a mechanical defect in the latching mechanism.
Findings
- The primary cause of the incident was the failure to properly close the gear door cover.
- It was not determined whether the unlatified cover resulted from improper manual handling during the pre-flight check or a mechanical malfunction of the device.
- The incident was an isolated event, as no similar failure has occurred on this specific aircraft.
Safety action
- The Technical Pilot for the Q-400 fleet was advised to consult with the manufacturer regarding the possibility of attempting gear retraction after identifying and correcting an open cover issue.
- A recommendation was made to revise the cockpit preparation checklist. Specifically, the instruction regarding the gear doors and landing gear inhibit switch was suggested to be updated to emphasize the necessity of verifying the closure of the cover.