Air safety

A crewman who performs a pre-flight inspection on an Airbus A320.

American Airlines Boeing 757 in final approach to Princess Juliana International Airport, on Playa Maho. Many accidents occur during take-off and landing manoeuvres, although take-off is more dangerous because the aircraft carries more fuel.

Air safety is the set of measures that aim to find out the causes of each air accident in order to modify operating procedures and training, so as to avoid its repetition. Flight safety investigations are complex and analyze numerous factors and, rather than investigate the responsible persons, try to find out the causes of the incident, considering human factors and technical issues.^{[citation needed]} The main resources of the investigators are the testimonies and reports of the crews, the analysis of the black boxes or the remains of the aircraft.

Statistics

According to the ICAO safety report for the year 2014, the total number of plane crashes in the United States of America 2013 was 90 worldwide. Only 9 of these accidents were "fatal accidents", that is, accidents with fatalities. The Civil Aviation Authority (UK) Global Review of Fatal Accidents gives a total of 0.6 fatal accidents per million flights for the ten-year period 2002 to 2011.

When expressed as per million flight hours, this number is 0.4. The corresponding number of fatalities is 22.0 deaths per million flights or 12.7 when expressed per million flight hours. The total number of deaths in 2013 was 173, which is the lowest number of deaths since 2000, although the total number of departures in 2013 was 32.1 million. This corresponds to 5.39 deaths per million departures in 2013.

The following table shows the development of the rate of fatal and non-fatal accidents in recent years.

The Civil Aviation Authority (UK) Global Review of Fatal Accidents gives a total of 0.6 fatal accidents per million flights for the ten-year period 2002 to 2011.

Not all phases of flight are equally accident prone. Most accidents (55%) occur during landing or takeoff. Only 10% occurs when the plane is en route.

Comparison with other modes of travel

There are three main ways the fatality risk of a given mode of travel can be measured: deaths per billion typical trips, deaths per billion hours traveled, or deaths per billion kilometers traveled.

The following table shows these statistics for 1990-2000. Please note that aviation security does not include transportation to the airport.

Number of passenger aircraft deaths (14+ passengers) helmet loss accidents per year. Red is the average 5 years.

Dangers to aviation safety

Foreign Objects

Foreign objects debris (FOD) is known as objects or elements that are left in the aircraft structure during its manufacture/repair, debris found on the runway, or solids found during transport. flight. These elements can damage the engines or other parts of the aircraft.

Human Factors

NASA Air Safety Experiment (Controlled Impact Demonstration Project). The plane is a Boeing 720 that testifies to a form of jet fuel, known as the "fraud geese", which formed a gel difficult to light when it is violently agitated, as in a shock.

Human factors, including pilot error, are another potential set of factors and are currently the most common factor found in aircraft accidents.

During World War II there was great progress in the application of human factors analysis to improve aviation safety, made by pioneers such as Paul Fitts and Alphonse Chapanis. However, progress has been made throughout the history of aviation, such as the development of the pilot's checklist in 1937. The CRM (Crew Resource Management) technique consists of making use of the experience and knowledge of the entire crew to avoid the reliance on a single crew member during the flight.

Pilot errors and communication problems are often factors in an aircraft crash. This can take place both in the air and on the ground. The ability of the aircrew to maintain an alert situation is a critical human factor in aviation safety.

The following is a graph made by ICAO, which indicates the number of accidents that occurred depending on the type of factor that caused them.

Graph legend

1. Ground-controlled flight (CFIT).
2. Loss of flight control (LOC-I).
3. Track safety (RS).
4. Ground safety (GS).
5. Operational damage (OD).
6. Persons injured and/or disabled (MED).
7. Others (OTH).
8. Unknown (UNK).

Pilot fatigue

ICAO defines fatigue as the physiological state of reduced mental or physical performance caused by lack of sleep, prolonged insomnia, or excessive workload. This phenomenon puts the crew and passengers in great danger because it significantly increases the chances of pilot error. Fatigue is particularly prevalent among pilots due to unplanned work hours, long periods, disruption of circadian cycles, and insufficient sleep. Regulatory organizations work to mitigate fatigue by limiting the number of hours a pilot is allowed to fly. Fatigue experts often find these methods insufficient to achieve the desired goals.

The European regulation proposes to launch a work program on pilot fatigue and performance. The program would consist of collecting data on a long-term basis, tracking the impact of new standards, evaluating the effectiveness of fatigue management in the industry, and researching specific issues as appropriate.

Piloting while intoxicated

Rarely are crew members arrested or subject to disciplinary action for being intoxicated while on duty. In 1990, three Northwest Airlines crew members were sentenced to jail time for flying drunk. In 2001, the same airline fired a pilot who tested positive for breathalyzer after a flight.

Controlled flight to the ground

Controlled flight into terrain (CFIT) is a type of accident in which the aircraft flies under the control of controlled structures on the ground. These accidents are caused by pilot error or a malfunction of the navigation systems.

Electromagnetic interference

The use of certain electronic equipment is partially or completely prohibited, as it may interfere with the operation of the aircraft, such as drift in the compass data. The use of some types of personal electronic devices is prohibited when an aircraft is below 10,000 feet, taking off or landing. The use of mobile phones is prohibited on most flights because their use inside the cabin causes problems with communications on the ground.

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 control or ground can lose spatial orientation, or make another mistake and consequently lead to accidents or a narrowly avoided collision.

Lightning Bolts

Boeing studies show that airliners are struck by lightning twice a year on average; Aircraft will withstand typical lightning attacks 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 could have caused the crash of Pan Am Flight 214 in 1963. At the time, the planes were not designed to withstand such strikes because their existence was unknown. The 1985 standard in effect in the United States at the time of the glider accident, Advisory Circular AC 20-53A, was superseded by Advisory Circular AC 20-53B in 2006. However, it is not clear whether a standard has been incorporated. adequate protection against positive lightning.

The effects of typical lightning strikes on traditional metal-covered aircraft are well known, and serious damage caused by lightning to an aircraft is rare. The Boeing 787 Dreamliner of which the exterior is carbon fiber reinforced polymer did not receive any lightning damage during testing.

Ice and Snow

Ice on a plane. Ice has caused numerous aviation accidents. Ice protection systems for aircraft are increasingly safe.

Ice and snow can be major factors in plane crashes. In 2005, Southwest Airlines Flight 1248 slid down a runway, after landing in heavy snow conditions, killing a child on the ground.

Even a small amount of ice or frost can greatly affect a wing's ability to develop adequate lift, so 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.

A buildup of ice during flight can be catastrophic, as evidenced by the loss of control and subsequent accidents of American Eagle Flight 4184 in 1994 and Comair Flight 3272 in 1997. Both aircraft were turboprop airliners with straight wings that tend to be more susceptible to icing on ice, than swept-wing jets.

Airlines and airports ensure that aircraft are properly de-iced before takeoff whenever the weather involves icing conditions. Modern aircraft are designed to prevent ice buildup on the wings, engines, and empennage, either by heating the air from the jet engines through the wing leading edges and inlets or in slower aircraft., rubber "boots" that expand to break up any accumulated ice.

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

Engine failure

Engine failure can occur from lack of fuel, damage caused by foreign objects, mechanical failure caused by metal fatigue, mechanical failure due to improper maintenance, mechanical failure caused by manufacturing defects or crew error..

In aircraft with more than one engine, the failure of one of the engines normally causes the emergency landing of the aircraft, landing at another airport closer to the destination, for example. If the failure of the second engine occurs or the damage of other aircraft systems due to this failure, if the emergency landing is not possible, it may cause the aircraft to have an accident.

Aircraft structural failure

Some examples of aircraft structural failure caused by metal fatigue include the de Havilland Comets accidents (1950s) and the Aloha Airlines Flight 243 accidents (1988). Thanks to this, this problem has been better studied and understood, which is why rigorous inspections and non-destructive tests are carried out to prevent this failure.

Composite materials are made up of layers of fibers embedded in a resin matrix. In some cases, due to the cyclical stress materials are subjected to, layers of material can separate from each other and lose strength. Since the failure occurs within the material, nothing can be seen on the surface, so it is necessary to use instrumental procedures to detect material failures, usually ultrasonic instruments are used.

Stalling

Crashes caused by a complete lockup of the airfoils include:

• 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 accident (2002)
• Turkish Airlines flight 1951 (2009)
• Air Flight 3407 (2009)
• Air France flight 447 (2009)

Fire

Fire is one of the biggest threats in the operation of aircraft, in whatever phase of flight, for which there are strict regulations regarding fire protection systems, regulating both the materials of the aircraft and the requirements that fire extinguishing systems must have. Normally these requirements detail the tests that have to be carried out, such as tests for the flammability of the materials, their toxicity or the smoke they emit. This is because if a test fails, it's better to fail on a prototype in an engineering lab than on an aircraft.

Bird Attack

In aviation there have been numerous accidents due to the collision of birds with aircraft, specifically due to the "ingestion" of the same by both engines or due to the collision of birds in the crew cabin.

That is why the engines have had to be designed to withstand the ingestion of birds of a certain weight and number and not lose more than a certain amount of thrust. The weight and number of birds that can be ingested without jeopardizing the safe flight of the aircraft is related to the engine inlet area. The risks of bird ingestion beyond the design limit were shown on US Airways Flight 1549 when a flock of Canadian goose struck the fuselage and engines.

The greatest risk of bird ingestion occurs during takeoff and landing in the vicinity of the airport, as well as in low-level flights carried out mostly by military, spraying, firefighting, or helicopter aircraft, among others. Among the methods used to avoid this type of accident is planting poisonous grass, which birds cannot tolerate.

Earth Damage

A lot of equipment operates in close proximity to the fuselage and wings to service the aircraft and occasionally causes accidental damage such as paint scratches or small dents. Since the aircraft structure (including the skin) plays a crucial role in the safety of operations during a flight, all damage has to be inspected, measured and checked to ensure that it is within the permitted safety tolerances.

Volcanic Ash

Ash plumes near active volcanic areas can damage propellers, engines, or crew cabin windows.

Security on the track

Types of track safety incidents include:

• Tracking - an incident involving only one aircraft making an inappropriate exit from the track.
• Track overflow - a specific type of excursion in which the aircraft does not stop before the end of the track (e.g. Air France Flight 358).
• Incursion on track - incorrect presence of a vehicle, person or other aircraft on the track (e.g., disaster at Tenerife airport).
• Confusion on the track - misidentification of the crew of the airstrip or take off (e.g. Comair Flight 5191, Singapore Airlines Flight 006).

Terrorism

Crews are normally trained to handle hijacking situations. Since the attacks of September 11, 2001, stricter airport and aviation security measures have been adopted to prevent terrorism, such as security checks and the locking of cabin doors during the flight.

Deliberate Crew Action

Although most aircraft crews are tested 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 Tokyo Haneda Airport, killing 24 of 174 on board. The official investigation found that the mentally ill captain had attempted suicide by putting the inboard engines in reverse thrust while the plane was close to the runway. The first officer did not have enough time to push back before the plane stalled and crashed.

In 1997, Silk Air Flight 185 suddenly entered a dive high from its cruising altitude. The speed of the dive was so high that the plane began to break up before it finally crashed near Palembang, Sumatra. After three years of investigation, the Indonesian authorities stated that the cause of the accident could not be determined. However, the United States 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 kilometers northwest of Nice in the French Alps after a steady descent that began a minute after the last routine contact with Y air control shortly after the aircraft reached its assigned cruising altitude. All 144 passengers and six crew died. The crash was intentionally caused by co-driver Andreas Lubitz. Having been declared "unable to work" without notifying his employer, Lubitz reported to the service, and during the flight he locked the pilot out of the cockpit. In response to the incident and the circumstances of Lubitz's involvement, aviation authorities in Canada, New Zealand, Germany, and Australia implemented new regulations requiring 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 cabin during the entire flight. Several airlines announced that they had already voluntarily adopted similar policies.

Military Action

Airliners have rarely been attacked in both peacetime and wartime. Examples:

• In 1955, Bulgaria dropped El Al Flight 402.
• In 1973, Israel dropped Libyan Arab Airlines Flight 114.
• In 1983, the Soviet Union dropped Korean Air Lines' 007 flight.
• In 1988, the United States dropped Iran Air Flight 655.
• In 2001, the Ukrainian Air Force accidentally dropped Siberia Airlines Flight 1812 during an exercise.
• In 2014, Russia dropped Flight 17 from Malaysia Airlines.
• In 2020, Iran dropped Flight 752 from Ukraine International Airlines.

International cooperation in aviation and agencies

European Aviation Safety Agency

The European Aviation Safety Agency collaborates with other international organizations, such as the Federal Aviation Administration (FAA) and the national authorities of Canada, Israel and Russia, whose mission is similar in their respective states, both for aviation safety and to ensure environmental protection in civil aviation.^{[citation required]}