In aviation , a controlled flight into terrain ( CFIT ; usually / ˈ s iː f ɪ t / SEE -fit ) is an accident in which an airworthy aircraft, fully under pilot control, is unintentionally flown into the ground, a body of water or other obstacle. In a typical CFIT scenario, the crew is unaware of the impending collision until impact, or it is too late to avert. The term was coined by engineers at Boeing in the late 1970s.
33-608: The Automatic Ground Collision Avoidance System (Auto-GCAS) enhances safety by mitigating controlled flight into terrain (CFIT) accidents. The Auto-GCAS team was awarded the 2018 Collier Trophy for the design-integration and flight testing in the F-35 , marking the year's greatest achievement in aeronautics. This team includes the Air Force Research Laboratory , Lockheed Martin , the F-35 Joint Program Office,
66-591: A TAWS. A study by the International Air Transport Association examined 51 accidents and incidents and found that pilots did not adequately respond to a TAWS warning in 47% of cases. Several factors can still place aircraft at risk for CFIT accidents: older TAWS systems, deactivation of the EGPWS system, or ignoring TAWS warnings when an airport is not in the TAWS database. Beginning in the early 1970s,
99-411: A likely future position of the aircraft intersects with the ground. The flight crew is thus provided with "earlier aural and visual warning of impending terrain, forward looking capability, and continued operation in the landing configuration." Class A TAWS includes all the requirements of Class B TAWS, below, and adds the following additional three alerts and display requirements of: Class B TAWS
132-469: A number of studies looked at the occurrence of CFIT accidents, where a properly functioning airplane under the control of a fully qualified and certificated crew is flown into terrain (or water or obstacles) with no apparent awareness on the part of the crew. In the 1960s and 70s, there was an average of one CFIT accident per month, and CFIT was the single largest cause of air travel fatalities during that time. C. Donald Bateman , an engineer at Honeywell ,
165-447: A requirement for large aircraft to carry such equipment, until the time of the report, there had not been a single passenger fatality in a CFIT crash by a large jet in U.S. airspace. After 1974, there were still some CFIT accidents that GPWS was unable to help prevent, due to the "blind spot" of those early GPWS systems. More advanced systems were developed. Older TAWS, or deactivation of the EGPWS, or ignoring its warnings when airport
198-606: A variety of systems may be developed in the near future that would meet the improved standards contained in the proposed final rule. The breakthrough that enabled successful EGPWS came after the dissolution of the Soviet Union in 1991; the USSR had created detailed terrain maps of the world, and Bateman convinced his director of engineering to purchase them after the political chaos made them available, enabling earlier terrain warnings. The TAWS improves on existing GPWS systems by providing
231-421: Is credited with developing the first ground proximity warning system ( GPWS ); in an early test, conducted after the 1971 crash of Alaska Airlines Flight 1866 , the device provided sufficient warning for a small plane to avoid the terrain, but not enough for the larger Boeing 727 jetliner involved. Bateman's earliest devices, developed in the 1960s, used radio waves to measure altitude and triggered an alarm when
264-595: Is defined by the U.S. FAA as: A class of equipment that is defined in TSO -C151b and RTCA DO-161A. As a minimum, it will provide alerts for the following circumstances: Class C defines voluntary equipment intended for small general aviation airplanes that are not required to install Class B equipment. This includes minimum operational performance standards intended for piston-powered and turbine-powered airplanes, when configured with fewer than six passenger seats, excluding any pilot seats. Class C TAWS equipment shall meet all
297-562: Is not in its database, still leave aircraft vulnerable to possible CFIT incidents. In April 2010, a Polish Air Force Tupolev Tu-154M aircraft crashed near Smolensk, Russia, in a possible CFIT accident killing all passengers and crew, including the Polish President. The aircraft was equipped with TAWS made by Universal Avionics Systems of Tucson. According to the Russian Interstate Aviation Committee TAWS
330-597: The Boeing 757 was equipped with the earlier GPWS, the terrain warning was issued only 13 seconds before the crash. In 1998, the FAA issued Notice No. 98-11, Terrain Awareness and Warning System, proposing that all turbine-powered U.S.-registered airplanes type certificated to have six or more passenger seats (exclusive of pilot and copilot seating), be equipped with an FAA-approved terrain awareness and warning system. On March 23, 2000,
363-407: The ground proximity warning system (GPWS) and the enhanced ground proximity warning system (EGPWS). The U.S. Federal Aviation Administration (FAA) introduced the generic term TAWS to encompass all terrain-avoidance systems that meet the relevant FAA standards, which include GPWS, EGPWS and any future system that might replace them. As of 2007, 5% of the world's commercial airlines still lacked
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#1732845404701396-561: The Defense Safety Oversight Council, and NASA . The Automatic Ground Collision Avoidance System uses inputs from terrain mapping, aircraft location, and automation to avoid ground collisions. The Auto-GCAS system detects imminent ground contact and warns the pilot. If there is no pilot response, the Auto-GCAS takes control, maneuvering to avoid ground contact. When on a safe trajectory, with pilot awareness, control returns to
429-517: The F-35 fleet. Controlled flight into terrain Accidents where the aircraft is out of control at the time of impact, because of mechanical failure or pilot error , are classified instead as uncontrolled flight into terrain, or UFIT. Incidents resulting from the deliberate action of the person at the controls, such as a forced landing , an act of terrorism , or suicide by pilot , are also excluded from
462-466: The FAA extended the GPWS requirement to Part 135 certificate holders operating smaller airplanes: turbojet-powered airplanes with ten or more passenger seats. These operators were required to install TSO-approved GPWS equipment or alternative ground proximity advisory systems that provide routine altitude callouts whether or not there is any imminent danger. This requirement was considered necessary because of
495-426: The FAA issued Amendments 91–263, 121–273, and 135-75 (Correction 135.154). These amendments amended the operating rules to require that all U.S. registered turbine-powered airplanes with six or more passenger seats (exclusive of pilot and copilot seating) be equipped with an FAA-approved TAWS. The mandate only affects aircraft manufactured after March 29, 2002. By 2006, aircraft upset accidents had overtaken CFIT as
528-562: The Gulf of Mexico, involving an Era Aviation Sikorsky S-76A++ helicopter with two pilots transporting eight oil service personnel, was one of many crashes that prompted the decision. President Barack Obama awarded the National Medal of Technology and Innovation to Bateman in 2010 for his invention of GPWS and its later evolution into EGPWS/TAWS. A modern TAWS works by using digital elevation data and airplane instrumental values to predict if
561-674: The aircraft was too low, but it was not aimed forward and could not provide sufficient warning of steeply rising terrain ahead. Findings from these early studies indicated that many such accidents could have been avoided if a GPWS had been used. As a result of these studies and recommendations from the U.S. National Transportation Safety Board ( NTSB ), in 1974 the FAA required all 14 CFR 121 (Part 121) certificate holders (that is, those operating large turbine-powered airplanes) and some 14 CFR 135 (Part 135) certificate holders (that is, those operating large turbojet airplanes) to install TSO -approved GPWS equipment. In 1978,
594-420: The cockpit during critical phases of the flight, such as when operating at below 10,000 feet (3,000 m). Terrain awareness and warning system In aviation, a terrain awareness and warning system ( TAWS ) is generally an on-board system aimed at preventing unintentional impacts with the ground, termed " controlled flight into terrain " accidents, or CFIT. The specific systems currently in use are
627-430: The complexity, size, speed, and flight performance characteristics of these airplanes. The GPWS equipment was considered essential in helping the pilots of these airplanes to regain altitude quickly and avoid what could have been a CFIT accident. Installation of GPWS or alternative FAA-approved advisory systems was not required on turbo-propeller powered (turboprop) airplanes operated under Part 135 because, at that time,
660-416: The crew, may mislead them into improperly guiding the aircraft despite other information received from properly functioning equipment. CFIT is a constant hazard during aerial application and aerial firefighting operations, which involve routine low-altitude flight along varying routes over terrain that may be unfamiliar to the pilots. Before the installation of the first electronic terrain warning systems,
693-483: The definition of CFIT. According to Boeing in 1997, CFIT was a leading cause of airplane accidents involving the loss of life, causing over 9,000 deaths since the beginning of the commercial jet aircraft . CFIT was identified as a cause of 25% of USAF Class A mishaps between 1993 and 2002. According to data collected by the International Air Transport Association (IATA) between 2008 and 2017, CFITs accounted for six percent of all commercial aircraft accidents, and
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#1732845404701726-407: The development of a new type of ground proximity warning system that provides greater situational awareness for flight crews. The FAA has approved certain installations of this type of equipment, known as the enhanced ground proximity warning system (EGPWS). However, in the proposed final rule, the FAA is using the broader term "terrain awareness and warning system" (TAWS) because the FAA expects that
759-509: The effectiveness of the alternative ground proximity advisory system to the GPWS. GPWS was found to be superior in that it would warn only when necessary, provide maximum warning time with minimal unwanted alarms, and use command-type warnings. Based on these reports and NTSB recommendations, in 1992 the FAA amended §135.153 to require GPWS equipment on all turbine-powered airplanes with ten or more passenger seats. After these rules were issued, advances in terrain mapping technology permitted
792-445: The flight crew much earlier aural and visual warning of impending terrain, forward looking capability, and continued operation in the landing configuration. These improvements provide more time for the flight crew to make smoother and gradual corrective action. United Airlines was an early adopter of the EGPWS technology. The CFIT of American Airlines Flight 965 in 1995 convinced that carrier to add EGPWS to all its aircraft; although
825-626: The general consensus was that the performance characteristics of turboprop airplanes made them less susceptible to CFIT accidents. For example, it was thought that turboprop airplanes had a greater ability to respond quickly in situations where altitude control was inadvertently neglected, as compared to turbojet airplanes. However, later studies, including investigations by the NTSB, analyzed CFIT accidents involving turboprop airplanes and found that many of these accidents could have been avoided if GPWS equipment had been used. Some of these studies also compared
858-436: The leading cause of aircraft accident fatalities, credited to the widespread deployment of TAWS. On March 7, 2006, the NTSB called on the FAA to require all U.S.-registered turbine-powered helicopters certified to carry at least 6 passengers to be equipped with a terrain awareness and warning system. The technology had not yet been developed for the unique flight characteristics of helicopters in 2000. A fatal helicopter crash in
891-474: The only defenses against CFIT were conventional see-and-avoid aviation practices, pilot simulator training, crew resource management (CRM) and radar surveillance by air traffic services . While refinements applied to those practices helped reduced the incidence of CFIT accidents, they did not eliminate them. To further assist in preventing CFIT accidents, manufacturers developed terrain awareness and warning systems (TAWS). The first generation of those systems
924-545: The pilot. Pilot unresponsiveness can be attributed to many factors including: distraction, task saturation, incapacitation, and unconsciousness. The Auto-GCAS system successfully reduced the leading cause of F-16 pilot fatalities. NASA started working on Auto-GCAS starting in 1997. The system was then jointly developed at the Lockheed Martin Skunk Works and at NASA . In July 2019, seven years ahead of schedule, Lockheed Martin began integration of Auto-GCAS into
957-401: The requirements of a Class B TAWS with the small aircraft modifications described by the FAA. The FAA has developed Class C to make voluntary TAWS usage easier for small aircraft. Prior to the development of GPWS, large passenger aircraft were involved in 3.5 fatal CFIT accidents per year, falling to 2 per year in the mid-1970s. A 2006 report stated that from 1974, when the U.S. FAA made it
990-446: The system has proved very effective in preventing further CFIT accidents. Smaller aircraft often use a GPS database of terrain to provide terrain warning. The GPS database contains a database of nearby terrain and will present terrain that is near the aircraft in red or yellow depending on its distance from the aircraft. The sterile flight deck rule was implemented to limit pilot distraction by banning any non-essential activities in
1023-493: The terrain below and immediately ahead of them. Fatigue can cause even highly experienced professionals to make significant errors, which culminate in a CFIT accident. CFIT accidents frequently involve a collision with terrain such as hills or mountains or tall artificial obstacles such as radio towers during conditions of reduced visibility while approaching or departing from an airport. A contributing factor can be subtle navigation equipment malfunctions which, if not detected by
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1056-506: Was categorized as "the second-highest fatal accident category after Loss of Control Inflight (LOC-I) ". While there are many reasons why an aircraft might crash into terrain, including poor weather and navigational equipment failure, pilot error is the most common factor found in CFIT accidents. Behind such events there is often a loss of situational awareness by the pilot, who becomes unaware of their actual position and altitude in relation to
1089-410: Was known as a ground proximity warning system (GPWS), which used a radar altimeter to assist in calculating terrain closure rates. That system was further improved with the addition of a GPS terrain database and is now known as an enhanced ground proximity warning system (EGPWS) . When combined with mandatory pilot simulator training which emphasizes proper responses to any caution or warning event,
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