Turbine engine failure

A turbine engine failure occurs when a gas turbine engine unexpectedly stops producing power due to a malfunction other than fuel exhaustion. It often applies for aircraft, but other turbine engines can also fail, such as ground-based turbines used in power plants or combined diesel and gas vessels and vehicles.

Turbine engines in use on today's turbine-powered aircraft are very reliable. Engines operate efficiently with regularly scheduled inspections and maintenance. These units can have lives ranging in the tens of thousands of hours of operation. However, engine malfunctions or failures occasionally occur that require an engine to be shut down in flight. Since multi-engine airplanes are designed to fly with one engine inoperative and flight crews are trained for that situation, the in-flight shutdown of an engine typically does not constitute a serious safety of flight issue.

The Federal Aviation Administration (FAA) was quoted as stating turbine engines have a failure rate of one per 375,000 flight hours, compared to of one every 3,200 flight hours for aircraft piston engines.^{[unreliable source]} Due to "gross under-reporting" of general aviation piston engines in-flight shutdowns (IFSD), the FAA has no reliable data and assessed the rate "between 1 per 1,000 and 1 per 10,000 flight hours". Continental Motors reports the FAA states general aviation engines experience one failures or IFSD every 10,000 flight hours, and states its Centurion engines failure is one per 20,704 flight hours, lowering to one per 163,934 flight hours in 2013–2014.

The General Electric GE90 has an in-flight shutdown rate (IFSD) of one per million engine flight-hours. The Pratt & Whitney Canada PT6 is known for its reliability with an in-flight shutdown rate of one per 333,333 hours from 1963 to 2016, lowering to one per 651,126 hours over 12 months in 2016.

Following an engine shutdown, a precautionary landing is usually performed with airport fire and rescue equipment positioned near the runway. The prompt landing is a precaution against the risk that another engine will fail later in the flight or that the engine failure that has already occurred may have caused or been caused by other as-yet unknown damage or malfunction of aircraft systems (such as fire or damage to aircraft flight controls) that may pose a continuing risk to the flight. Once the aircraft lands, fire department personnel assist with inspecting the aircraft to ensure it is safe before it taxis to its parking position.

Turboprop-powered aircraft and turboshaft-powered helicopters are also powered by turbine engines and are subject to engine failures for many similar reasons as jet-powered aircraft. In the case of an engine failure in a helicopter, it is often possible for the pilot to enter autorotation, using the unpowered rotor to slow the aircraft's descent and provide a measure of control, usually allowing for a safe emergency landing even without engine power.

Most in-flight shutdowns are harmless and likely to go unnoticed by passengers. For example, it may be prudent for the flight crew to shut down an engine and perform a precautionary landing in the event of a low oil pressure or high oil temperature warning in the cockpit. However, passengers in a jet powered aircraft may become quite alarmed by other engine events such as a compressor surge — a malfunction that is typified by loud bangs and even flames from the engine's inlet and tailpipe. A compressor surge is a disruption of the airflow through a gas turbine jet engine that can be caused by engine deterioration, a crosswind over the engine's inlet, ice accumulation around the engine inlet, ingestion of foreign material, or an internal component failure such as a broken blade. While this situation can be alarming, the engine may recover with no damage.

Other events that can happen with jet engines, such as a fuel control fault, can result in excess fuel in the engine's combustor. This additional fuel can result in flames extending from the engine's exhaust pipe. As alarming as this would appear, at no time is the engine itself actually on fire.^{[citation needed]}