Aviation safety

A crewman performing a pre-flight inspection in an Airbus A320.

Aviation safety is a term encompassing the theory, investigation, and categorization of flight failures, and the prevention of such failures through regulation, education, and training. It can also be applied in the context of campaigns that inform the public as to the safety of air travel.

Institutions

United States

During the 1920s, the first laws were passed in the USA to regulate civil aviation. Of particular significance was the Air Commerce Act (1926) which required pilots and aircraft to be examined and licensed, for accidents to be properly investigated, and for the establishment of safety rules and navigation aids, under the Aeronautics Branch of the United States Department of Commerce.

Despite this, in 1926 and 1927 there were a total of 24 fatal commercial airline crashes, a further 16 in 1928, and 51 in 1929 (killing 61 people), which remains the worst year on record at an accident rate of about 1 for every 1,000,000 miles (1,600,000 km) flown. Based on the current numbers flying, this would equate to 7,000 fatal incidents per year.

The fatal incident rate has declined steadily ever since, and since 1997 the number of fatal air accidents has been no more than 1 for every 2,000,000,000 person-miles flown (e.g., 100 people flying a plane for 1,000 miles (1,600 km) counts as 100,000 person-miles, making it comparable with methods of transportation with different numbers of passengers, such as one person driving an automobile for 100,000 miles (160,000 km), which is also 100,000 person-miles), and thus one of the safest modes of transportation when measured by distance traveled.

The World Bank has published the reliable data of the frequency of passengers carried by Air Transport in the Year 2012 obtained from the International Civil Aviation Organization (ICAO). The United States of America has the largest number of Commercial Air Transport Passengers. 756,617,000 cf. China the next largest with 318,475,924. The United States had an International Flight frequency of 9,560,451 in 2012. The Civil Aviation Authority, JAR and EASA have published that there is a fatal accident ratio of one per million flights. The main cause is Pilot in Command error.

Between 1990–2006, there were 1441 commuter and air taxi crashes in the U.S. of which 373 (26%) were fatal, resulting in 1063 deaths (142 occupational pilot deaths). A disproportionate number of all U.S. aircraft crashes occur in Alaska, largely as a result of severe weather conditions. Alaska accounted for 513 (36%) of the total U.S. crashes.

Another aspect of safety is protection from attack currently known as Security (as the ISO definition of safety encompasses non-intentional (safety_safety) and intentional (safety_security) causes of harm or property damage). The terrorist attacks of 2001 are not counted as accidents. However, even if they were counted as accidents they would have added about 2 deaths per 2,000,000,000 person-miles. Two months later, American Airlines Flight 587 crashed in New York City, killing 256 people including 5 on the ground, causing 2001 to show a very high fatality rate. Even so, the rate that year including the attacks (estimated here to be about 4 deaths per 1,000,000,000 person-miles), is safe compared to some other forms of transport when measured by distance traveled.

Safety has improved from better aircraft design, engineering and maintenance, the evolution of navigation aids, and safety protocols and procedures.

It is often reported that air travel is the safest in terms of deaths per passenger mile. The National Transportation Safety Board (2006) reports 1.3 deaths per hundred million vehicle miles for travel by car, and 1.7 deaths per hundred million vehicle miles for travel by air. However, airplanes often have hundreds of passengers, unlike road vehicles. The number of deaths per passenger mile on commercial airlines in the United States between 1995 and 2000 is about 3 deaths per 10 billion passenger miles.

Navigation aids and instrument flight

An airborne pulse-Doppler radar antenna. Some airborne radars can be used as meteorological radars.

A modern-day Honeywell Intuvue weather system visualizes weather patterns up to 300 miles away. One of the first navigation aids to be introduced (in the USA in the late 1920s) was airfield lighting to assist pilots to make landings in poor weather or after dark. The Precision Approach Path Indicator was developed from this in the 1930s, indicating to the pilot the angle of descent to the airfield. This later became adopted internationally through the standards of the International Civil Aviation Organization (ICAO).

In 1929 Jimmy Doolittle developed instrument flight.

With the spread of radio technology, several experimental radio based navigation aids were developed from the late 1920s onwards. These were most successfully used in conjunction with instruments in the cockpit in the form of Instrument landing systems (ILS), first used by a scheduled flight to make a landing in a snowstorm at Pittsburgh, Pennsylvania, in 1938. A form of ILS was adopted by the ICAO for international use in 1949.

Following the development of Radar in World War II, it was deployed as a landing aid for civil aviation in the form of ground-controlled approach (GCA) systems, joined in 1948 by distance measuring equipment (DME), and in the 1950s by airport surveillance radar as an aid to air traffic control. VHF omnidirectional range (VOR) stations became the predominant means of route navigation during the 1960s, superseding the low frequency radio ranges and the non-directional beacon (NDB). The ground based VOR stations were often co-located with DME transmitters. With the proper receiving equipment in the aircraft, pilots could know their radials in degrees to/from the VOR station, as well as the slant range distance. A number of ground based Weather radar systems can detect areas of severe turbulence.

Ground-based navigation aids are being supplanted by satellite-based aids like Global Positioning System (GPS), which make it possible for pilots to know their position with great precision anywhere in the world. With the arrival of Wide Area Augmentation System (WAAS), Satellite navigation has become accurate enough for vertical (altitude) as well as horizontal use, and is being used increasingly for instrument approaches as well as en-route navigation. However, because the GPS constellation is a single point of failure, on-board Inertial Navigation System (INS) or ground-based navigation aids are still required for backup.

In June 2014 the International Air Transport Association said it was working on implementing new measures to track aircraft in flight in real time. A special panel was considering a range of options including the production of equipment especially designed to ensure real time tracking.

Aviation safety hazards

Foreign object debris

Main article: Foreign object debris

Foreign object debris (FOD) includes items left in the aircraft structure during manufacture/repairs, debris on the runway and solids encountered in flight (e.g. hail and dust). Such items can damage engines and other parts of the aircraft. Air France Flight 4590 crashed after hitting a part that had fallen from another aircraft.

Misleading information and lack of information

A pilot misinformed by a printed document (manual, map, etc.), reacting to a faulty instrument or indicator (in the cockpit or on the ground), or following inaccurate instructions or information from flight or ground control can lose spatial orientation, or make another mistake, and consequently lead to accidents or nearmisses.

Lightning

Boeing studies showed that airliners are struck by lightning twice per year on average; aircraft withstand typical lightning strikes without damage.

The dangers of more powerful positive lightning were not understood until the destruction of a glider in 1999. It has since been suggested that positive lightning might have caused the crash of Pan Am Flight 214 in 1963. At that time, aircraft were not designed to withstand such strikes because their existence was unknown. The 1985 standard in force in the US at the time of the glider crash, Advisory Circular AC 20-53A, was replaced by Advisory Circular AC 20-53B in 2006. However, it is unclear whether adequate protection against positive lightning was incorporated.

The effects of typical lightning on traditional metal-covered aircraft are well understood and serious damage from a lightning strike on an airplane is rare. The Boeing 787 Dreamliner of which the exterior is carbon-fiber-reinforced polymer received no damage from a lightning strike during testing.

Ice and snow

Ice and snow can be major factors in airline accidents. In 2005, Southwest Airlines Flight 1248 slid off the end of a runway after landing in heavy snow conditions, killing one child on the ground.

Even a small amount of icing or coarse frost can greatly impair the ability of a wing to develop adequate lift, which is why regulations prohibit ice, snow or even frost on the wings or tail, prior to takeoff. Air Florida Flight 90 crashed on takeoff in 1982, as a result of ice/snow on its wings.

An accumulation of ice during flight can be catastrophic, as evidenced by the loss of control and subsequent crashes of American Eagle Flight 4184 in 1994, and Comair Flight 3272 in 1997. Both aircraft were turboprop airliners, with straight wings, which tend to be more susceptible to inflight ice accumulation, than are swept-wing jet airliners.

Airlines and airports ensure that aircraft are properly de-iced before takeoff whenever the weather involves icing conditions. Modern airliners are designed to prevent ice buildup on wings, engines, and tails (empennage) by either routing heated air from jet engines through the leading edges of the wing, and inlets, or on slower aircraft, by use of inflatable rubber "boots" that expand to break off any accumulated ice.

Airline flight plans require airline dispatch offices to monitor the progress of weather along the routes of their flights, helping the pilots to avoid the worst of inflight icing conditions. Aircraft can also be equipped with an ice detector in order to warn pilots to leave unexpected ice accumulation areas, before the situation becomes critical. Pitot tubes in modern airplanes and helicopters have been provided with the function of "Pitot Heating" to prevent accidents like Air France Flight 447 caused by the pitot tube freezing and giving false readings.

Engine failure

Further information: Turbine engine failure and ETOPS

An engine may fail to function because of fuel starvation (e.g. British Airways Flight 38), fuel exhaustion (e.g. Gimli Glider), foreign object damage (e.g. US Airways Flight 1549), mechanical failure due to metal fatigue (e.g. Kegworth air disaster, El Al Flight 1862, China Airlines Flight 358), mechanical failure due to improper maintenance (e.g. American Airlines Flight 191), mechanical failure caused by an original manufacturing defect in the engine (e.g. Qantas Flight 32, United Airlines Flight 232, Delta Air Lines Flight 1288), and pilot error (e.g. Pinnacle Airlines Flight 3701).

In a multi-engine aircraft, failure of a single engine usually results in a precautionary landing being performed, for example landing at a diversion airport instead of continuing to the intended destination. Failure of a second engine (e.g. US Airways Flight 1549) or damage to other aircraft systems caused by an uncontained engine failure (e.g. United Airlines Flight 232) may, if an emergency landing is not possible, result in the aircraft crashing.

Structural failure of the aircraft

Examples of failure of aircraft structures caused by metal fatigue include the de Havilland Comet accidents (1950s) and Aloha Airlines Flight 243 (1988). Now that the subject is better understood, rigorous inspection and nondestructive testing procedures are in place.

Composite materials consist of layers of fibers embedded in a resin matrix. In some cases, especially when subjected to cyclic stress, the layers of the material separate from each other (delaminate) and lose strength. As the failure develops inside the material, nothing is shown on the surface; instrument methods (often ultrasound-based) have to be used to detect such a material failure. In the 1940s several Yakovlev Yak-9s experienced delamination of plywood in their construction.

Stalling

Stalling an aircraft (increasing the angle of attack to a point at which the wings fail to produce enough lift) is dangerous and can result in a crash if the pilot fails to make a timely correction.

Devices to warn the pilot when the aircraft's speed is decreasing close to the stall speed include stall warning horns (now standard on virtually all powered aircraft), stick shakers, and voice warnings. Most stalls are a result of the pilot allowing the airspeed to be too slow for the particular weight and configuration at the time. Stall speed is higher when ice or frost has attached to the wings and/or tail stabilizer. The more severe the icing, the higher the stall speed, not only because smooth airflow over the wings becomes increasingly more difficult, but also because of the added weight of the accumulated ice.

Crashes caused by a full stall of the airfoils include:

• British European Airways Flight 548 (1972)
• United Airlines Flight 553 (1972)
• Aeroflot Flight 7425 (1985)
• Arrow Air Flight 1285 (1985)
• Northwest Airlines Flight 255 (1987)
• The Paul Wellstone crash (2002)
• Turkish Airlines Flight 1951 crash (2009)
• Colgan Air Flight 3407 (2009)
• Air France Flight 447 (2009)

Fire

NASA air safety experiment (CID project)

Safety regulations control aircraft materials and the requirements for automated fire safety systems. Usually these requirements take the form of required tests. The tests measure flammability of materials and toxicity of smoke. When the tests fail, it is on a prototype in an engineering laboratory rather than in an aircraft.

Fire and its toxic smoke have been the cause of accidents. An electrical fire on Air Canada Flight 797 in 1983 caused the deaths of 23 of the 46 passengers, resulting in the introduction of floor level lighting to assist people to evacuate a smoke-filled aircraft. In 1985, a fire on the runway caused the loss of 55 lives, 48 from the effects of incapacitating and subsequently lethal toxic gas and smoke in the British Airtours Flight 28M accident which raised serious concerns relating to survivability – something that had not been studied in such detail. The swift incursion of the fire into the fuselage and the layout of the aircraft impaired passengers' ability to evacuate, with areas such as the forward galley area becoming a bottle-neck for escaping passengers, with some dying very close to the exits. Much research into evacuation and cabin and seating layouts was carried out at Cranfield Institute to try to measure what makes a good evacuation route, which led to the seat layout by Overwing exits being changed by mandate and the examination of evacuation requirements relating to the design of galley areas. The use of smoke hoods or misting systems were also examined although both were rejected.

South African Airways Flight 295 was lost in the Indian Ocean in 1987 after an in-flight fire in the cargo hold could not be suppressed by the crew. The cargo holds of most airliners are now equipped with automated halon fire extinguishing systems to combat a fire that might occur in the baggage holds. In May 1996, ValuJet Flight 592 crashed into the Florida Everglades a few minutes after takeoff because of a fire in the forward cargo hold. All 110 people on board were killed.

At one time, fire fighting foam paths were laid down before an emergency landing, but the practice was considered only marginally effective, and concerns about the depletion of fire fighting capability due to pre-foaming led the United States FAA to withdraw its recommendation in 1987.

One possible cause of fires in airplanes is wiring problems that involve intermittent faults, such as wires with breached insulation touching each other, having water dripping on them, or short circuits. These are difficult to detect once the aircraft is on the ground. However, there are methods, such as spread-spectrum time-domain reflectometry, that can feasibly test live wires on aircraft during flight.

Bird strike

Main article: Bird strike

Bird strike is an aviation term for a collision between a bird and an aircraft. Fatal accidents have been caused by both engine failure following bird ingestion and bird strikes breaking cockpit windshields.

Jet engines have to be designed to withstand the ingestion of birds of a specified weight and number and to not lose more than a specified amount of thrust. The weight and numbers of birds that can be ingested without hazarding the safe flight of the aircraft are related to the engine intake area. The hazards of ingesting birds beyond the "designed-for" limit were shown on US Airways Flight 1549 when the aircraft struck Canada geese.

The outcome of an ingestion event and whether it causes an accident, be it on a small fast plane, such as military jet fighters, or a large transport, depends on the number and weight of birds and where they strike the fan blade span or the nose cone. Core damage usually results with impacts near the blade root or on the nose cone.

The highest risk of a bird strike occurs during takeoff and landing in the vicinity of airports, and during low-level flying by military aircraft, crop dusters and helicopters for example. Some airports use active countermeasures, ranging from a person with a shotgun through recorded sounds of predators to employing falconers. Poisonous grass can be planted that is not palatable to birds, nor to insects that attract insectivorous birds. Passive countermeasures involve sensible land-use management, avoiding conditions attracting flocks of birds to the area (e.g. landfills). Another tactic found effective is to let the grass at the airfield grow taller (approximately 12 inches (30 cm)) as some species of birds won't land if they cannot see one another.

Human factors

See also: aviation medicine

NASA air safety experiment (CID project). The airplane is a Boeing 720 testing a form of jet fuel, known as "antimisting kerosene", which formed a difficult-to-ignite gel when agitated violently, as in a crash.

Human factors, including pilot error, are another potential set of factors, and currently the factor most commonly found in aviation accidents. Much progress in applying human factors analysis to improving aviation safety was made around the time of World War II by such pioneers as Paul Fitts and Alphonse Chapanis. However, there has been progress in safety throughout the history of aviation, such as the development of the pilot's checklist in 1937. CRM, or Crew Resource Management, is a technique that makes use of the experience and knowledge of the complete flight crew to avoid dependence on just one crew member.

Pilot error and improper communication are often factors in the collision of aircraft. This can take place in the air (1978 Pacific Southwest Airlines Flight 182) (TCAS) or on the ground (1977 Tenerife disaster) (RAAS). The barriers to have an effective communication have internal and external factors. The ability of the flight crew to maintain situation awareness is a critical human factor in air safety. Human factors training is available to general aviation pilots and called single pilot resource management training.

Failure of the pilots to properly monitor the flight instruments caused the crash of Eastern Air Lines Flight 401 in 1972. Controlled flight into terrain (CFIT), and error during take-off and landing can have catastrophic consequences, for example causing the crash of Prinair Flight 191 on landing, also in 1972.

Pilot fatigue

Main article: Pilot Fatigue

The International Civil Aviation Organization (ICAO) defines fatigue as "A physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase, or workload." The phenomenon places great risk on the crew and passengers of an airplane because it significantly increases the chance of pilot error. Fatigue is particularly prevalent among pilots because of "unpredictable work hours, long duty periods, circadian disruption, and insufficient sleep". These factors can occur together to produce a combination of sleep deprivation, circadian rhythm effects, and 'time-on task' fatigue. Regulators attempt to mitigate fatigue by limiting the amount of hours pilots are allowed to fly over varying periods of time. Experts in aviation fatigue often find that these methods fall short on their goals.

Piloting while intoxicated

Rarely, flight crew members are arrested or subject to disciplinary action for being intoxicated on the job. In 1990, three Northwest Airlines crew members were sentenced to jail for flying while drunk. In 2001, Northwest fired a pilot who failed a breathalyzer test after a flight. In July 2002, both pilots of America West Airlines Flight 556 were arrested just before they were scheduled to fly because they had been drinking alcohol. The pilots were fired and the FAA revoked their pilot licenses. At least one fatal airliner accident involving drunk pilots occurred when Aero Flight 311 crashed at Koivulahti, Finland, killing all 25 on board in 1961, which underscores the role that poor human choices can play in air accidents.

Human factors incidents are not limited to errors by pilots. Failure to close a cargo door properly on Turkish Airlines Flight 981 in 1974 caused the loss of the aircraft – however, design of the cargo door latch was also a major factor in the accident. In the case of Japan Airlines Flight 123, improper repair of previous damage led to explosive decompression of the cabin, which in turn destroyed the vertical stabilizer and damaged all four hydraulic systems which powered all the flight controls.

Controlled flight into terrain

Main article: Controlled flight into terrain

Controlled flight into terrain (CFIT) is a class of accidents in which an aircraft is flown under control into terrain or man-made structures. CFIT accidents typically result from pilot error or of navigational system error. Failure to protect ILS critical areas can also cause CFIT accidents. In December 1995, American Airlines Flight 965 tracked off course while approaching Cali, Colombia and hit a mountainside despite a terrain awareness and warning system (TAWS) terrain warning in the cockpit and desperate pilot attempt to gain altitude after the warning. Crew position awareness and monitoring of navigational systems are essential to the prevention of CFIT accidents. As of February 2008, over 40,000 aircraft had enhanced TAWS installed, and they had flown over 800 million hours without a CFIT accident.

Another anti-CFIT tool is the Minimum Safe Altitude Warning (MSAW) system which monitors the altitudes transmitted by aircraft transponders and compares that with the system's defined minimum safe altitudes for a given area. When the system determines the aircraft is lower, or might soon be lower, than the minimum safe altitude, the air traffic controller receives an acoustic and visual warning and then alerts the pilot that the aircraft is too low.

Electromagnetic interference

See also: Mobile phones on aircraft and Electromagnetic interference

The use of certain electronic equipment is partially or entirely prohibited as it might interfere with aircraft operation, such as causing compass deviations. Use of some types of personal electronic devices is prohibited when an aircraft is below 10,000', taking off, or landing. Use of a mobile phone is prohibited on most flights because in-flight usage creates problems with ground-based cells.

Ground damage

Various ground support equipment operate in close proximity to the fuselage and wings to service the aircraft and occasionally cause accidental damage in the form of scratches in the paint or small dents in the skin. However, because aircraft structures (including the outer skin) play such a critical role in the safe operation of a flight, all damage is inspected, measured, and possibly tested to ensure that any damage is within safe tolerances.

An example problem was the depressurization incident on Alaska Airlines Flight 536 in 2005. During ground services a baggage handler hit the side of the aircraft with a tug towing a train of baggage carts. This damaged the metal skin of the aircraft. This damage was not reported and the plane departed. Climbing through 26,000 feet (7,900 m) the damaged section of the skin gave way under the difference in pressure between the inside of the aircraft and the outside air. The cabin depressurized explosively necessitating a rapid descent to denser (breathable) air and an emergency landing. Post landing examination of the fuselage revealed a 12 in (30 cm) hole on the right side of the airplane.

Volcanic ash

Main article: Volcanic ash and aviation safety

Plumes of volcanic ash near active volcanoes can damage propellers, engines and cockpit windows. In 1982, British Airways Flight 9 flew through an ash cloud and temporarily lost power from all four engines. The plane was badly damaged, with all the leading edges being scratched. The front windscreens had been so badly "sand" blasted by the ash that they could not be used to land the aircraft.

Prior to 2010 the general approach taken by airspace regulators was that if the ash concentration rose above zero, then the airspace was considered unsafe and was consequently closed. Volcanic Ash Advisory Centers enable liaison between meteorologists, volcanologists, and the aviation industry.

Runway safety

Main article: Runway safety

Types of runway safety incidents include:

• Runway excursion – an incident involving only a single aircraft making an inappropriate exit from the runway.
• Runway overrun – a specific type of excursion where the aircraft does not stop before the end of the runway (e.g., Air France Flight 358).
• Runway incursion – incorrect presence of a vehicle, person, or another aircraft on the runway (e.g., Tenerife airport disaster).
• Runway confusion – crew misidentification the runway for landing or take-off (e.g., Comair Flight 191, Singapore Airlines Flight 6).

Terrorism

Aircrew are normally trained to handle hijack situations. Since the September 11, 2001 attacks, stricter airport and airline security measures are in place to prevent terrorism, such as security checkpoints and locking the cockpit doors during flight.

Deliberate aircrew action

Although most air crews are screened for psychological fitness, some have taken suicidal actions. In the case of EgyptAir Flight 990, it appears that the first officer deliberately crashed into the Atlantic Ocean while the captain was away from his station in 1999 off Nantucket, Massachusetts.

In 1982, Japan Airlines Flight 350 crashed while on approach to the Tokyo Haneda Airport, killing 24 of the 174 on board. The official investigation found the mentally ill captain had attempted suicide by placing the inboard engines into reverse thrust, while the aircraft was close to the runway. The first officer did not have enough time to countermand before the aircraft stalled and crashed.

In 1997, SilkAir Flight 185 suddenly went into a high dive from its cruising altitude. The speed of the dive was so high that the aircraft began to break apart before it finally crashed near Palembang, Sumatra. After three years of investigation, the Indonesian authorities declared that the cause of the accident could not be determined. However, the US NTSB concluded that deliberate suicide by the captain was the only reasonable explanation.

In 2015, on March 24, Germanwings Flight 9525 (an Airbus A320-200) crashed 100 kilometres (62 mi) northwest of Nice, in the French Alps, after a constant descent that began one minute after the last routine contact with air traffic control and shortly after the aircraft had reached its assigned cruise altitude. All 144 passengers and six crew members were killed. The crash was intentionally caused by the co-pilot, Andreas Lubitz. Having been declared "unfit to work" without telling his employer, Lubitz reported for duty, and during the flight locked the pilot out of the cabin. In response to the incident and the circumstances of Lubitz's involvement, aviation authorities in Canada, New Zealand, Germany and Australia implemented new regulations that require two authorized personnel to be present in the cockpit at all times. Three days after the incident the European Aviation Safety Agency issued a temporary recommendation for airlines to ensure that at least two crew members, including at least one pilot, are in the cockpit at all times of the flight. Several airlines announced they had already adopted similar policies voluntarily.

Military action

Passenger planes have rarely been attacked in both peacetime and war. Examples:

• In 1973, Israel shot down Libyan Arab Airlines Flight 114.
• In 1983, the Soviet Union shot down Korean Air Lines Flight 007.
• In 1988, the United States shot down Iran Air Flight 655.
• In 2001, the Ukrainian Air Force accidentally shot down Siberia Airlines Flight 1812 during an exercise.
• In 2014, an as of yet undetermined party in Ukraine shot down Malaysia Airlines Flight 17.

Accident survivability

Further information: Pre-flight safety demonstration, Aircraft safety card, Brace position, Aircraft rescue and firefighting, and Airport crash tender

Airport design

Airport design and location can have a large impact on aviation safety, especially since some airports such as Chicago Midway International Airport were originally built for propeller planes and many airports are in congested areas where it is difficult to meet newer safety standards. For instance, the FAA issued rules in 1999 calling for a runway safety area, usually extending 500 feet (150 m) to each side and 1,000 feet (300 m) beyond the end of a runway. This is intended to cover ninety percent of the cases of an aircraft leaving the runway by providing a buffer space free of obstacles. Many older airports do not meet this standard. One method of substituting for the 1,000 feet (300 m) at the end of a runway for airports in congested areas is to install an engineered materials arrestor system (EMAS). These systems are usually made of a lightweight, crushable concrete that absorbs the energy of the aircraft to bring it to a rapid stop. As of 2008, they have stopped three aircraft at JFK Airport.

Emergency airplane evacuations

According to a 2000 report by the National Transportation Safety Board, emergency aircraft evacuations happen about once every 11 days in the U.S. While some situations are extremely dire, such as when the plane is on fire, in many cases the greatest challenge for passengers can be the use of the evacuation slide. In a Time article on the subject, Amanda Ripley reported that when a new supersized Airbus A380 underwent mandatory evacuation tests in 2006, 33 of the 873 evacuating volunteers got hurt. While the evacuation was considered a success, one volunteer suffered a broken leg, while the remaining 32 received slide burns. Such accidents are common. In her article, Ripley provided tips on how to make it down the airplane slide without injury.

Accidents and incidents

• List of airship accidents
• Lists of aviation accidents and incidents
• Aviation accidents and incidents
• List of airliner shootdown incidents
• Flight recorder, includes flight data recorder and cockpit voice recorder

Statistics

According to the 2014 ICAO safety report, the total number of plane accidents in 2013 was 90 worldwide. Only 9 of these accidents were fatal accidents, that is, accidents involving fatalities. The Global Fatal Accident Review of the Civil Aviation Authority gives a total number of 0.6 fatal accidents per one million flights for the ten-year period 2002 to 2011. When expressed as per million hours flown, this number is 0.4. The corresponding number of fatalities is 22.0 fatalities per one million flights or 12.7 when expressed as per million hours flown. The total number of fatalities in 2013 was 173, which is the smallest number of fatalities since 2000, even though the total number of departures in 2013 was a record 32.1 million. This corresponds to 5.39 fatalities per one million departures in 2013. The following chart shows the development of the rate of fatal and non-fatal accidents in recent years.

Airplane accident statistics (world-wide)

Year	Number of accidents per one million departures
2009	4.1
2010	4.2
2011	4.2
2012	3.2
2013	2.8

Not all phases of flight are equally prone to accidents. Most accidents (55%) occur during landing or take-off. Only 10% occur when the aircraft is en route.

Accidents by phase of flight (2013)

Phase	Percentage of accidents that occur in this phase
Landing	43
Approach	18
Take-off	12
En route	10
Standing	9
Taxi	8

Comparison to other modes of travel

There are three main ways in which risk of fatality of a certain mode of travel can be measured: Deaths per billion typical journeys taken, deaths per billion hours travelled, or deaths per billion kilometers traveled. The following table displays these statistics for 1990–2000. Note that aviation safety does not include the transportation to the airport.

Deaths

Type	per bn journeys	per bn hours	per bn km
Bus	4.3	11.1	0.4
Rail	20	30	0.6
Van	20	60	1.2
Car	40	130	3.1
Foot	40	220	54.2
Water	90	50	2.6
Air	117	30.8	0.05
Pedal cycle	170	550	44.6
Motorcycle	1640	4840	108.9

The first two statistics are computed for typical travels for respective forms of transport, so they cannot be used directly to compare risks related to different forms of transport in a particular travel "from A to B". For example: according to statistics, a typical flight from Los Angeles to New York will carry a larger risk factor than a typical car travel from home to office. But a car travel from Los Angeles to New York would not be typical. It would be as large as several dozens of typical car travels, and associated risk will be larger as well. Because the journey would take a much longer time, the overall risk associated by making this journey by car will be higher than making the same journey by air, even if each individual hour of car travel can be less risky than an hour of flight.

It is therefore important to use each statistic in a proper context. When it comes to a question about risks associated with a particular long-range travel from one city to another, the most suitable statistic is the third one, thus giving a reason to name air travel as the safest form of long-range transportation. However, if the availability of an air option makes an otherwise inconvenient journey possible, then this argument loses some of its force.

Aviation industry insurers base their calculations on the deaths per journey statistic while the aviation industry itself generally uses the deaths per kilometre statistic in press releases.

Fatalities have been in constant decline since the mid-1990s, while the number of passenger flight-hours has kept increasing since the 1950s.

Number of fatalities from airliners (14+ passengers) hull loss accidents per year. In red is the 5-year average.

National investigation organizations

• Australian Transport Safety Bureau
• Flugunfalluntersuchungsstelle im BMVIT (Austria)
• Transportation Safety Board of Canada
• Air Accidents Investigation Institute (Czech Republic)
• Danish Aircraft Accident Investigation Board
• Bureau d'Enquêtes et d'Analyses pour la sécurité de l'Aviation Civile (France)
• Bundesstelle für Flugunfalluntersuchung (Germany)
• Air Accident Investigation Unit (Ireland)
• Aircraft and Railway Accidents Investigation Commission (Japan)
• Civil Aviation Authority of New Zealand
• Transport Accident Investigation Commission (New Zealand)
• Civil Aviation Authority of the Philippines
• Comisión de Investigación de Accidentes e Incidentes de Aviación Civil (Spain)
• Swedish Accident Investigation Board
• Aircraft Accident Investigation Bureau (Switzerland)
• Air Accidents Investigation Branch (UK)
• National Transportation Safety Board (USA)
• European Co-ordination Center for Aircraft Incident Reporting Systems (ECCAIRS)
• International Civil Aviation Organisation
• South African Civil Aviation Authority (South Africa)

Air safety investigators

These individuals are trained and authorized to conduct aviation accident and incident investigations for the government organizations responsible for aviation safety. They possess specialized expertise and training in specific fields, such as aircraft structures, air traffic control, flight recorders and human factors. They may be employed by governments, manufacturers or unions and perform fact-finding, analyses, and report writing as part of their duties.

Safety improvement initiatives

The safety improvement initiatives are aviation safety partnerships between regulators, manufacturers, operators, professional unions, research organisations, and international aviation organisations to further enhance safety. Some major safety initiatives worldwide are:

• Commercial Aviation Safety Team (CAST) in the US. The Commercial Aviation Safety Team (CAST) was founded in 1998 with a goal to reduce the commercial aviation fatality rate in the United States by 80 percent by 2007.
• European Strategic Safety Initiative (ESSI) . The European Strategic Safety Initiative (ESSI) is an aviation safety partnership between EASA, other regulators and the industry. The initiative objective is to further enhance safety for citizens in Europe and worldwide through safety analysis, implementation of cost effective action plans, and coordination with other safety initiatives worldwide.

Regulation

• Civil Aviation Authority (United Kingdom)
• Department of Infrastructure, Transport, Regional Development and Local Government (Australia)
• European Aviation Safety Agency
• Federal Aviation Administration (United States)
  • Federal Aviation Regulations
• Irish Aviation Authority
• Transport Canada

See also

• Aircraft hijacking
• Airport security
• Aviation Safety Network
• Aviation Safety Reporting System
• Ballistic parachute
• Crashworthiness
• Hazard analysis
• Health hazards of air travel
• IATA Operational Safety Audit
• Jet Airliner Crash Data Evaluation Centre
• Lasers and aviation safety
• Mid-air collision
• Pilot error
• Safety of emergency medical services flights
• Sensory illusions in aviation
• SKYbrary
• Swiss cheese model
• Tombstone mentality
• Travel § Safety
• Uncontrolled decompression
• Wind shear
• Zonal Safety Analysis

External links

• 10 Plane Crashes That Changed Aviation
• Template:Dmoz
• Safety Behaviours, a guide for pilots (comprehensive human factors information)
• NASA Aviation Safety Reporting System (ASRS)
• Latest Aviation Safety Occurrences at the Aviation Safety Network
• Aviation Safety: Advancements Being Pursued to Improve Airliner Cabin Occupant Safety and Health, 2003