What happened
On July 17, 2020, a Boeing 737-800, registration SP-ESH, was taxiing to the runway at Krakow Airport (EPKT) when the crew received a "MASTER CAUTION – ENG – ENGINE CONTROL" warning related to engine number 1. Following established Non-Normal Checklist (NNC) procedures, the crew returned the aircraft to the parking stand.
The aircraft was subsequently removed from service to allow for technical inspection and necessary repairs.
The investigation
The investigation focused on the technical failure that triggered the engine control alert. Maintenance personnel inspected the engine and identified a malfunction within the Hydromechanical Unit (HMU), which is responsible for delivering fuel to the combustion chambers and managing engine support systems.
Findings
- The primary cause of the event was a malfunction of the engine fuel system's hydromechanical unit (HMU).
- The technical issue was resolved by replacing the faulty HMU with a new unit, after which the aircraft was cleared for return to service.