Incident Overview
A scheduled commercial passenger flight experienced an engine component separation while climbing through 3,000 feet mean sea level, approximately 4 nautical miles from the departure airport. The number two engine's low pressure turbine module separated from the engine and departed the airplane. The flight subsequently returned to the departure airport.
Examination Findings
Post-incident examination of the lubrication system revealed extensive contamination and blockages. The B-sump forward scavenge screen was completely blocked with coke, including several metallic flakes. The largest metallic flake measured 1/3 inch by 1/3 inch. The screen was also partially collapsed. An oil sample taken from the B-sump forward scavenge line was black and contained black particles.
The B-sump aft scavenge screen was estimated to be approximately 90 percent blocked and contained some metallic flakes. An oil sample from the B-sump aft scavenge line was also black and contained black particles. The C-sump forward scavenge screen exhibited about 75 percent blockage with coke, though the center portion of the screen remained clear. The C-sump aft screen was 5 percent blocked.
Additionally, the oil filter contained black particles and black oil. The impending bypass button on the oil filter was found in the popped position, indicating that the filter had reached a bypass condition due to contamination.
No further details regarding the aircraft type, registration, operator, or occupant status were provided in the source. The investigation did not specify a probable cause for the separation or the observed oil system condition.