What happened
On June 16, 2017, a Boeing 737-800 operated by Enter Air experienced a technical issue shortly after departing from Palermo Airport (LICJ). Following the retraction of the flaps after takeoff, the cockpit warning 'LE FLAPS IN TRANSIT' remained illuminated.
The flight crew initiated the relevant Non-Normal Checklist (NNC) for the 'LE FLAPS IN TRANSIT' condition. Following the procedures outlined in the checklist, the crew continued the flight toward the destination airport, Toulouse-Blagnac (LFBO) in France. In accordance with the NNC instructions, the crew performed the landing using flaps in the 15-degree position.
The investigation
Upon arrival at the destination, the captain recorded the occurrence in the technical logbook and notified the Maintenance Control Center (MCC). Maintenance personnel conducted an inspection of the aircraft's flap systems. The investigation established that the issue was localized to a specific component of the flap mechanism.
Findings
- The investigation identified the malfunction of the outboard left flap proximity sensor as the cause of the warning light remaining illuminated.
- Following the identification of the faulty sensor, technical staff replaced the OUTBOARD PROXIMITY SENSOR.
- The aircraft successfully passed all required operational tests following the component replacement and was subsequently returned to service.