Event Summary
On 4 February 2016, a Boeing 737-400 operated by Enter Air experienced a left-side WING BODY OVERHEAT warning immediately after pushback from the parking stand at Hurghada Airport (HEGN), Egypt. The crew decided to return to the parking position, made an entry in the EDP-1, and notified the MCC (Maintenance Control Center).
Operational Response
Due to the unavailability of cabin crew, the captain authorized the flight using a one-time authorization (number 01/ENE/16/01) in accordance with MEL 26.12 and MEL 21.1.1.1. The flight plan was updated and additional fuel was loaded because the maximum flight level was restricted to FL250. The aircraft then departed for Poznan (EPPO), Poland, with the left engine bleed air supply switched off.
Technical Inspection and Resolution
Upon arrival in Poznan, maintenance personnel inspected the WING BODY OVERHEAT system. No leaks were found, and a sensor test produced normal results. After resetting the warning block, the light extinguished. The MEL restrictions (26.12 and 21.1.1.1) were removed, and the aircraft was returned to unrestricted service.
Investigation Findings
The investigation concluded that the most probable cause of the event was an incorrect operation of the WING BODY OVERHEAT warning system for an undetermined reason. No safety recommendations were issued.