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. [1] 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 to fly with one engine inoperative, 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. [2] [ 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". [3] Continental Motors reports the FAA states general aviation engines experience one failures or IFSD every 10,000 flight hours, and states its Centurion engines is one per 20,704 flight hours, lowering to one per 163,934 flight hours in 2013–2014. [4]
The General Electric GE90 has an in-flight shutdown rate (IFSD) of one per million engine flight-hours. [5] 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, [6] lowering to one per 651,126 hours over 12 months in 2016. [7]
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. [8]
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. [9]
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 ]
Also, the failure of certain components in the engine may result in a release of oil into bleed air that can cause an odor or oily mist in the cabin. This is known as a fume event. The dangers of fume events are the subject of debate in both aviation and medicine. [10]
Engine failures can be caused by mechanical problems in the engine itself, such as damage to portions of the turbine or oil leaks, as well as damage outside the engine such as fuel pump problems or fuel contamination. A turbine engine failure can also be caused by entirely external factors, such as volcanic ash, bird strikes or weather conditions like precipitation or icing. Weather risks such as these can sometimes be countered through the usage of supplementary ignition or anti-icing systems. [11]
A turbine-powered aircraft's takeoff procedure is designed around ensuring that an engine failure will not endanger the flight. This is done by planning the takeoff around three critical V speeds, V1, VR and V2. V1 is the critical engine failure recognition speed, the speed at which a takeoff can be continued with an engine failure, and the speed at which stopping distance is no longer guaranteed in the event of a rejected takeoff. VR is the speed at which the nose is lifted off the runway, a process known as rotation. V2 is the single-engine safety speed, the single engine climb speed. [12] The use of these speeds ensure that either sufficient thrust to continue the takeoff, or sufficient stopping distance to reject it will be available at all times.[ citation needed ]
In order to allow twin-engined aircraft to fly longer routes that are over an hour from a suitable diversion airport, a set of rules known as ETOPS (Extended Twin-engine Operational Performance Standards) is used to ensure a twin turbine engine powered aircraft is able to safely arrive at a diversionary airport after an engine failure or shutdown, as well as to minimize the risk of a failure. ETOPS includes maintenance requirements, such as frequent and meticulously logged inspections and operation requirements such as flight crew training and ETOPS-specific procedures. [13]
Engine failures may be classified as either as "contained" or "uncontained".
The very specific technical distinction between a contained and uncontained engine failure derives from regulatory requirements for design, testing, and certification of aircraft engines under Part 33 of the U.S. Federal Aviation Regulations, which has always required turbine aircraft engines to be designed to contain damage resulting from rotor blade failure. [15] Under Part 33, engine manufacturers are required to perform blade off tests to ensure containment of shrapnel if blade separation occurs. [16] Blade fragments exiting the inlet or exhaust can still pose a hazard to the aircraft, and this should be considered by the aircraft designers. [15] A nominally contained engine failure can still result in engine parts departing the aircraft as long as the engine parts exit via the existing openings in the engine inlet or outlet, and do not create new openings in the engine case containment. Fan blade fragments departing via the inlet may also cause airframe parts such as the inlet duct and other parts of the engine nacelle to depart the aircraft due to deformation from the fan blade fragment's residual kinetic energy.
The containment of failed rotating parts is a complex process which involves high energy, high speed interactions of numerous locally and remotely located engine components (e.g., failed blade, other blades, containment structure, adjacent cases, bearings, bearing supports, shafts, vanes, and externally mounted components). Once the failure event starts, secondary events of a random nature may occur whose course and ultimate conclusion cannot be precisely predicted. Some of the structural interactions that have been observed to affect containment are the deformation and/or deflection of blades, cases, rotor, frame, inlet, casing rub strips, and the containment structure. [15]
Uncontained turbine engine disk failures within an aircraft engine present a direct hazard to an airplane and its crew and passengers because high-energy disk fragments can penetrate the cabin or fuel tanks, damage flight control surfaces, or sever flammable fluid or hydraulic lines. [17] Engine cases are not designed to contain failed turbine disks. Instead, the risk of uncontained disk failure is mitigated by designating disks as safety-critical parts, defined as the parts of an engine whose failure is likely to present a direct hazard to the aircraft. [17]
United Airlines Flight 232 was a regularly scheduled United Airlines flight from Stapleton International Airport in Denver to O'Hare International Airport in Chicago, continuing to Philadelphia International Airport. On July 19, 1989, the DC-10 serving the flight crash-landed at Sioux Gateway Airport in Sioux City, Iowa, after suffering a catastrophic failure of its tail-mounted engine due to an unnoticed manufacturing defect in the engine's fan disk, which resulted in the loss of all flight controls. Of the 296 passengers and crew on board, 112 died during the accident, while 184 people survived. Thirteen of the passengers were uninjured. It was the deadliest single-aircraft accident in the history of United Airlines.
The Pratt & Whitney PW4000 is a family of dual-spool, axial-flow, high-bypass turbofan aircraft engines produced by Pratt & Whitney as the successor to the JT9D. It was first run in April 1984, was FAA certified in July 1986, and was introduced in June 1987. With thrust ranging from 50,000 to 99,040 lbf, it is used on many wide-body aircraft.
The General Electric GE90 is a family of high-bypass turbofan aircraft engines built by GE Aerospace for the Boeing 777, with thrust ratings from 81,000 to 115,000 pounds-force. It entered service with British Airways in November 1995. It is one of three options for the 777-200, -200ER, and -300 versions, and the exclusive engine of the -200LR, -300ER, and 777F. It was the largest jet engine, until being surpassed in January 2020 by its successor, the 110,000 lbf (490 kN) GE9X, which has a larger fan diameter by 6 inches (15 cm). However, the GE90-115B, the most recent variant of the GE90, is rated for a higher thrust than the GE9X.
New York Airways was an American helicopter airline in the New York City area, founded in 1949 as a mail and cargo carrier. On 9 July 1953 it may have been the first scheduled helicopter airline to carry passengers in the United States, with headquarters at LaGuardia Airport. Although primarily a helicopter airline operator with scheduled passenger operations, New York Airways also flew fixed wing aircraft, such as the de Havilland Canada DHC-6 Twin Otter 19-passenger STOL twin turboprop aircraft.
National Airlines Flight 27 was a scheduled passenger flight between Miami, Florida, United States, and San Francisco, California, United States, with intermediate stops at New Orleans, Houston and Las Vegas.
Blade off testing or blade out testing is a specific form of air safety testing required by the Federal Aviation Administration and other safety agencies to certify safety performance of jet engines. The tests require engine manufacturers to carry out at least two tests of the engine, to make sure that the engine can survive a compressor or fan blade breaking off within the engine and a turbine blade breaking off within the engine, without fragments being thrown through the outside enclosure of the engine, creating a contained engine failure.
Indian Airlines Flight 171 was a Caravelle that crashed while attempting an emergency landing at Bombay Airport on 12 October 1976 after suffering an uncontained engine failure, killing all 95 people on board. Metal fatigue in the No. 2 engine's 10th stage high-pressure compressor disk had caused it to disintegrate, the resulting fragments severed fuel lines causing fuel to leak into the engine and ignite causing an uncontrolled fire that eventually affected control surfaces leading to a loss of control.
Delta Air Lines Flight 1288 was a regularly scheduled flight from Pensacola, Florida to Atlanta, Georgia. On July 6, 1996, the aircraft serving the flight, a McDonnell Douglas MD-88, was on takeoff roll from Runway 17 at Pensacola when it experienced an uncontained, catastrophic turbine engine failure that caused debris from the front compressor hub of the left engine to penetrate the left aft fuselage. The cause of the engine failure was found to have been a fault in the manufacture of the fan. The failure of the airline to spot the resulting crack in the blade was a contributing factor.
British Airways Flight 2276 was a scheduled international passenger service from Las Vegas to London. On 8 September 2015, the Boeing 777-200ER operating the flight suffered an uncontained engine failure and fire in the left (#1) GE90 engine during take-off from Las Vegas-McCarran International Airport, prompting an aborted take-off and the evacuation of all passengers and crew. All 170 people on board survived, but 20 were injured.
On 27 May 2016, a Boeing 777-300 of Korean Air, operating as Korean Air Flight 2708 from Haneda Airport in Tokyo to Seoul's Gimpo International Airport, was accelerating for take off when its left engine suffered an uncontained failure and a substantial fire ensued. The crew aborted the take-off, and after the aircraft came to a stop the fire was extinguished by the airport emergency services. All 319 passengers and crew were evacuated; 9 occupants received minor injuries. The accident was attributed to poor maintenance standards and failure of the crew to carry out the emergency procedures correctly.
American Airlines Flight 383 was a scheduled passenger flight from O'Hare International Airport in Chicago, Illinois to Miami International Airport. On October 28, 2016, the Boeing 767-300ER operating the flight suffered an engine fire during takeoff. The crew aborted their takeoff, evacuating everyone on board, of whom 21 were injured. The plane was a write-off.
Centurion Air Cargo Flight 164 was a chartered international cargo flight, flying from Bogota's El Dorado International Airport while en route to Miami International Airport. The flight was operated by Kalitta Air and the aircraft was wet leased by Centurion Air Cargo. On 7 July 2008, the aircraft, a Boeing 747-209BSF registered as N714CK, crashed shortly after takeoff. All aboard suffered injuries, but none were killed. Two people on the ground were killed after the plane slammed into a farm. The crash was the second crash of a Boeing 747 in 2008 in Kalitta Air service, after a previous accident at Brussels in May.
Southwest Airlines Flight 3472 was a regularly scheduled passenger flight operating from New Orleans International Airport in New Orleans, Louisiana to Orlando International Airport in Orlando, Florida. On August 27, 2016, the Boeing 737-7H4, with 99 passengers and five crew, 12 minutes after departure from New Orleans, was climbing through 31,000 feet and heading east over the Gulf of Mexico when the aircraft's number one CFM International CFM56-7 engine suffered an engine failure. A fan blade in the engine broke due to a fatigue crack. The separated portion of the blade rotated within the engine, moving forward, striking the engine inlet. Debris from the damaged engine inlet punctured the left side of the fuselage causing a loss of cabin pressure and damaged the wing and empennage. Oxygen masks were deployed to passengers while the crew initiated an emergency descent to 10,000 feet. The aircraft then diverted to Pensacola International Airport for a safe landing about 20 minutes later without further incident. While the aircraft sustained substantial damage, there were no injuries.
Aeroflot Flight A-13 was a scheduled Soviet domestic passenger flight from Baku, Azerbaijan to Fort-Shevchenko in Kazakhstan that crashed on 18 August 1973 shortly after takeoff killing 56 of the 64 passengers and crew aboard. The Antonov An-24 had suffered an engine failure on takeoff and was attempting to return to the airport when it struck an oil rig cable at low altitude resulting in a crash. At the time, it was the second deadliest accident involving the An-24 and remains the second deadliest aviation accident in Azerbaijani history. The engine failure had been caused by the effect of continuous overheating on the performance of the blades.
On 27 April 1974, an Aeroflot Il-18 airliner crashed while operating a charter flight from Leningrad to Zaporizhzhia, continuing to Krasnodar, Russia. The plane crashed shortly after takeoff from Pulkovo Airport in Leningrad. None of the 109 people on board survived. The engine fire was caused by the uncontained failure of a faulty compressor disk.
On February 13, 2018, around noon local time, a Boeing 777-222 airplane, operating as United Airlines Flight 1175 (UA1175), experienced an in-flight separation of a fan blade in the No. 2 (right) engine while over the Pacific Ocean en route from San Francisco International Airport to the Daniel K. Inouye International Airport, Honolulu, Hawaii. During level cruise flight shortly before beginning a descent from flight level 360, and about 120 miles from HNL, the flight crew heard a loud bang, followed by a violent shaking of the airplane, followed by warnings of a compressor stall. The flight crew shut down the failed engine, declared an emergency, and began a drift-down descent, proceeding direct to HNL where they made a single-engine landing without further incident at 12:37 local time. There were no reported injuries to the 374 passengers and crew on board and the airplane damage was classified as minor under National Transportation Safety Board (NTSB) criteria.
Southwest Airlines Flight 1380 was a Boeing 737-700 that experienced a contained engine failure in the left CFM International CFM56 engine after departing from New York–LaGuardia Airport en route to Dallas Love Field on April 17, 2018. The engine cowl was broken in the failure, and cowl fragments damaged the fuselage, shattering a cabin window and causing explosive depressurization of the aircraft. Other fragments caused damage to the wing. The crew carried out an emergency descent and diverted to Philadelphia International Airport. One passenger was partially ejected from the aircraft and sustained fatal injuries, while eight other passengers sustained minor injuries. The aircraft was substantially damaged.
On Saturday 15 September 2001, TAM Linhas Aéreas Flight 9755, a Fokker 100 scheduled domestic passenger flight carrying 88 passengers and six crew, departed Recife/Guararapes–Gilberto Freyre International Airport for Viracopos International Airport. During the flight, the plane suffered an uncontained engine failure. Fragments of the engine shattered three cabin windows, causing decompression and blowing the passenger in seat 19E partly out of the plane. The passenger blown out of the window did not survive.
On February 20, 2021, United Airlines Flight 328 (UA328/UAL328), a scheduled U.S. domestic passenger flight from Denver to Honolulu, suffered what was technically ruled a contained engine failure despite shedding large pieces of debris, approximately four minutes after takeoff from Denver International Airport (DEN). Parts departing from the engine cowling of the Boeing 777-222 aircraft resulted in a debris field at least 1 mile (1.6 km) long over suburban residential areas of Broomfield, Colorado. Falling debris was recorded by eyewitnesses using smartphone cameras and a dash cam. Debris fell through the roof of a private home and significantly damaged a parked vehicle.
Overseas National Airways (ONA) Flight 032 was a non-scheduled positioning flight operated by Overseas National Airways with a McDonnell Douglas DC-10-30CF. On November 12, 1975, the flight crew initiated a rejected takeoff after accelerating through a large flock of gulls at John F. Kennedy International Airport, resulting in a runway excursion. Of the 139 aircraft occupants, all survived, while the aircraft was destroyed by an intense post-crash fire. The National Transportation Safety Board concluded that the probable cause of the accident was bird ingestion into the right-hand engine, causing an uncontained engine failure that ruptured several landing gear tires and disabled the engine's hydraulic system, in turn partially disabling the spoilers and the landing gear brakes. Contributing to the accident was the resultant failure of the affected engine's thrust reverser and the wet runway. The accident aircraft is claimed to be the largest commercial airliner ever destroyed due to a bird strike.
a helicopter can be landed safely in the event of an engine failure
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