Incident Details
On 3 October 2016, at 05:13 UTC, the flight crew of a Bombardier DHC-8-400 operated by LOT Polish Airlines began starting engine 2 after completing ground handling at Warsaw Chopin Airport (EPWA). During the start sequence, the engine failed to accelerate normally, exhibiting a slow increase in NH (rotor speed). The crew identified the condition as a hang start and shut down engine 2 in accordance with the ABNORMAL ENGINE START checklist.
While the engine was starting, smoke was observed emanating from under the engine cowling. The coordinator noticed the smoke but experienced difficulty communicating with the flight crew due to a damaged external headset jack. The coordinator resorted to hand signals to alert the crew. After the engine was shut down, the smoke stopped.
The airport fire brigade was called by the coordinator but did not need to take any firefighting action. The crew notified ATC (Ground) and the maintenance control center (MCC) about the aborted start. An appropriate entry was made in the LDP-60 log. The passengers disembarked, and the flight was eventually operated with a different aircraft, resulting in a delay.
Technical staff performed an inspection and cleared the aircraft for subsequent flights. An Aviation Safety Report (ASR) was filed after the flight.
Cause
The incident was attributed to a hang start phenomenon, which caused the slow spool-up (slow NH increase) of engine 2.