The twenty-first century is the century of technology and scientific knowledge with much emphasis on safety and security of all means of transportation. Why do airplane crashes still take place despite these advancements?
Even though the Transportation Security Administration screens over 1.8 million passengers every day, flying carries inherent, built-in risks. Planes are machines, and machines sometimes malfunction. Flight attendants and pilots may even fly several times per week, and although the airlines take as many precautions as possible, at these speeds and altitudes, mistakes can have serious consequences. According to the American National Safety Council, the odds of dying in an aviation accident in the US (over a lifetime) are about 1 in 7,178, while the odds of dying in a car crash are 1 in 98.
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. There are different devices which warn the pilot when the aircraft’s speed is decreasing close to the stall speed including stall warning horns (now standard on virtually all powered aircraft), stick shakers, and voice warnings.
Fire and its toxic smoke have been the causes of accidents. An electrical fire on Air Canada Flight 797 in 1983 caused the deaths of 23 of the 46 passengers. The other 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.
Around 12% of all plane crashes are caused by weather conditions. Although flights are often grounded when weather conditions are deemed hazardous, storms, heavy winds and even fog can sneak up on pilots and air traffic controllers. Lightning strikes can be especially dangerous. When lightning hits a plane, it can disable it in many ways.
Ice and snow can be major environmental factors in airline accidents. 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.
Plane crashes that are caused by sabotage draw the most media attention, but they only account for about 9% of total plane crashes. Regarding terrorism and hijack, the aircrew are normally trained to handle hijack situations. The strict airport and airline security measures are in place to prevent terrorism, such as security checkpoints and locking the cockpit doors during flight. Mentally ill passengers have been known to attack both pilots and passengers, and some have even detonated bombs in an attempt to commit suicide while in flight.
The bulk of the remaining plane crashes, about 7%, are caused by other kinds of human errors. Some plane crashes are inadvertently caused by air traffic controllers. Air traffic control mistakes have caused planes to crash into mountains, to land on occupied runways and even to collide in midair. When a plane is loaded, fuelled or maintained incorrectly, that’s human error too.
Electromagnetic interference by the use of certain electronic equipment has been proven fatal hence they are partially or entirely prohibited as it might interfere with aircraft operation such as causing compass deviations. Use of a mobile phone is prohibited on most flights because in-flight usage creates problems with ground-based cells.
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 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.
The 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.
Making use of the three Ps – pilots, planes and plans along with proper crew resource management – making use of the experience and knowledge of the complete flight crew to avoid dependence on just one crew member – need synchronisation to avoid precipitation of crashes.
(culled from nation.com.pk)
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