Incident Overview
On March 30, 2017, an ATR72-212 operating a scheduled flight from EYKA to EVRA experienced an engine surge shortly after departure. During climb at approximately 2500 feet and 05:50 UTC, the left engine surged. The crew reduced power to flight idle (FI), which resolved the surge. When power was increased, the surge recurred, prompting a second reduction to FI.
Crew Actions
Following the checklist procedure (No. 2.06), the crew was instructed to shut down the engine. However, given the aircraft was in a favorable position for an immediate landing and the engine parameters at FI were normal, the crew decided to land with the left engine throttled to FI and shut it down after landing. The aircraft landed safely at 06:00 UTC. After the landing roll, the left engine was shut down.
Post-Flight Inspection
Technical personnel inspected the left engine and discovered metal chips in the oil system of the engine and gearbox. Visual identification indicated the chips originated from a bearing. The engine was removed and sent for repair, where damage to bearing No. 5 was confirmed.
Probable Cause
The engine surge resulted from improper high-pressure shaft operation caused by damage to bearing No. 5.
Safety Recommendations
No safety recommendations were issued by the investigating commission.