The US National Transportation Safety Board defines an aviation accident as "an occurrence associated with the operation of an aircraft which takes place between the time any person boards the aircraft with the intention of flight and all such persons have disembarked, and in which any person suffers death or serious injury, or in which the aircraft receives substantial damage".
An aviation incident, on the other hand, is "an occurrence other than an accident, associated with the operation of an aircraft, which affects or could affect the safety of operations".
Other countries adopt a similar approach, although there are minor variations, such as to the extent of aviation-related operations on the ground covered, as well as with respect to the thresholds beyond which an injury is considered serious or the damage is considered substantial.
Air supporting mass
Since the birth of flight, aircraft have crashed, often with serious consequences. This is due to the unforgiving nature of flight, where a relatively insubstantial medium, air, supports a significant mass.
Should this support fail, there is limited opportunity for a good outcome. Because of this, aircraft design is concerned with minimising the chance of failure, and pilots are trained with safety as a primary consideration.
Despite this, accidents still occur, although nowadays statistically flying is an extremely safe form of transportation. In fact, the relative rarity of incidents, coupled with the often dramatic outcome, is one reason why they still make headlines.
The following is a look at the 10 deadliest air crashes in history.
27 March 1977
Number of people killed: 583
Two Boeing 747s, operated by KLM and Pan Am, collide on a foggy runway at Tenerife, in Spain's Canary Islands. The KLM jet departed without permission, striking the Pan Am jet as it taxied along the same runway. Confusion over instructions and a blockage of radio transmissions contributed to the crash.
2. Mount Fuji
12 August 1985
Number of people killed: 520
A Japan Air Lines 747 crashes near Mount Fuji after takeoff from Tokyo on a domestic flight. The rupture of an aft bulkhead, which had undergone faulty repairs following a mishap seven years earlier, caused the destruction of part of the aeroplane's tail and rendered the jet uncontrollable. A JAL maintenance supervisor later committed suicide, while the president of the airline resigned, accepting full responsibility for the crash and visiting victims' families to offer a personal apology.
12 November 1996
Number of people killed: 349
An Ilyushin IL-76 cargo plane from Kazakhstan collides in midair with a Saudia 747 near Delhi, India. The Kazakh crew had disobeyed instructions, and neither aircraft was equipped with collision-avoidance technology.
3 March 1974
Number of people killed: 346
A THY (Turkish Airlines) DC-10 crashes near Orly airport outside Paris. A poorly designed cargo door burst from its latches, leading to rapid depressurisation, failure of the cabin floor and impairment of cables to the rudders and elevators. Out of control, the plane slammed into woods northeast of Paris. McDonnell Douglas, maker of the DC-10, which would see even more controversy later, was forced to redesign its cargo door system.
23 June 1985
Number of people killed: 329
A bomb planted by Sikh extremists blows up an Air India 747 en route from Toronto to Bombay. The plane fell into the sea east of Ireland.
The weather is blamed for about
7% of aviation accidents
Investigators in Canada cited shortcomings in baggage screening procedures, screening equipment, and employee training. A second bomb, intended to blow up another Air India 747 on the same day, detonated prematurely in a luggage facility in Tokyo before being loaded aboard.
19 August 1980
Number of people killed: 301
A Saudia L-1011 bound for Karachi returns to Riyadh, Saudi Arabia, when a fire broke out on board shortly after takeoff. For reasons never fully understood, the crew delays evacuation after a safe touchdown and the aircraft rolls to the far end of the runway before finally stopping. No evacuation is commenced, and the plane then sits with its engines running for more than three minutes. Before any doors can be opened by the inadequately equipped rescue workers at Riyadh, everyone on the widebody died as the passenger cabin is killed by a flash-fire.
7. Straits of Hormuz
3 July 1988
Number of people killed: 290
An Airbus A300 operated by Iran Air is shot down over the Straits of Hormuz by the US navy destroyer Vincennes. The US military said the crew of the Vincennes were distracted by an ongoing armed battle and mistook the A300 for a hostile military aircraft. None of the passengers or crew survived.
25 May 1979
Number of people killed: 273
As an American Airlines DC-10 takes off from Chicago's O'Hare airport, an engine detaches from its mounting seriously damaging a wing. Before its crew can react, the aeroplane rolls 90 degrees and disintegrates in a fireball about a mile beyond the runway. This remains the worst-ever US crash. Both the engine pylon design and airline maintenance procedures were faulted by NTSB investigators, and all DC-10s were temporarily grounded.
21 December 1988
Number of people killed: 270
Pan American flight 103, explodes in the night sky over Lockerbie, Scotland, killing all the passengers, and 11 people on the ground. Two Libyan agents are later held responsible (one is convicted) for planting a bomb aboard the aircraft.
10. Sakhalin Island
1 September 1983
Number of people killed: 269
Korean Air Lines flight KL007, a 747, from New York to Seoul (with a technical stop in Anchorage) is shot down by a Soviet fighter after drifting off course - and into Soviet airspace - near Sakhalin Island in the North Pacific. The International Civil Aviation Organisation (ICAO) later attributes the mysterious deviation to "a considerable degree of lack of alertness and attentiveness on the part of the flight crew."
A statistical breakdown also includes the following:
Number of Boeing 747s involved in the 10 crashes: seven
Number resulting from terrorist sabotage or that were shot down mistakenly: four
Number that occurred in the US: one
Number that occurred prior to 1974: nil
Number that occurred during the 1970s or 1980s: nine
Number in which pilot error can be cited as a direct or contributing cause: three
Number that crashed as a direct result of mechanical failure: three
An accident survey of 2147 aeroplane accidents from 1950 through 2004 determined the causes to be as follows:
37%: Pilot error
33%: Undetermined or missing in the record
13%: Mechanical failure
5%: Sabotage (bombs, hijackings, shoot-downs)
4%: Other human error (air traffic controller error, improper loading of aircraft, improper maintenance, fuel contamination, language miscommunication, etc)
1%: Other cause
The survey excluded military, private, and charter aircraft.
Sources: Wikipedia.org; Salon.com. (Article by Patrick Smith); airlinesafety.com
Compiled and edited by Asim Khan.