Reasons for the Removal of Aircraft Turbine Engine
In the world of aviation maintenance, few procedures are as strenuous or demanding as removing an aircraft’s engine. Expensive and labor-intensive, it is something few technicians wish to do. Still there are numerous good reasons for removing an aircraft’s reciprocating engine or turbine engine.
Aircraft Engine’s life is dependent on factors such as operational use, quality of manufacture or overhaul, the type of aircraft and operations it carries out, and the degree of maintenance accomplished. Manufacturers will set engine removal time as well. Based on service experience, technicians can establish a maximum expected time before overhaul (TBO), the span of time within which an engine needs to be overhauled. An engine must be removed, regardless of condition, when it reaches the end of its TBO period.
Engine stoppage is a rapid and complete stoppage of an engine’s functions. Stoppages can be caused by engine seizure, propeller strikes, landing gear collapse, or crash-landings. A sudden stoppage can cause heavy internal damage, such as cracked propeller teeth, gear train damage, warped propeller bearings, and more. After a sudden stoppage occurs, replacement or disassembly and inspection is almost always required.
Another common reason for the removal of reciprocating or turbine engine is a sudden reduction in engine speed, which often occurs when a propeller blade strikes an object while operating at low engine RPM. After impact, the foreign object is cleared and the engine continues to run unless stopped to prevent further damage. While the engine can seemingly continue to run without issue, it is best to stop the flight and inspect the engine.
Metal particles in the engine’s oil screens or magnetic chip detectors are often an indication of partial internal failure of the engine. Carbon tends to break loose from the interior of the engine in rock-like pieces that have the appearance of metal, so check if any particles that have been found are magnetic first by placing them in proximity with a magnet. If the particles are magnetic, and thus made out of metal, the next step is to determine the extent of the damage; if only small particles are found, similar to filings, the oil system can be drained, refilled, and then test-run to see if particles continue to show up in the oil screens and chip detectors. If there is no evidence of foreign material, the engine can continue in service.
General operational problems like excessive vibrations, backfiring or misfiring, exceeding normal operation parameters, or low power output can also force an engine removal operation.
