Capt. Josiah Choms (PhD), a leader in the aviation sector and currently serving on the Board of HeliOffshore provides some education on air transportation in general and causes of aircraft accidents in particular, in such a way as to allay fears and restore confidence in a troubled industry. Accidents or serious incidents with passenger or cargo aircraft often attract overwhelming public interest, particularly if they involve large numbers of fatalities or a well-known and respected operator. Truth is that air travel is one of the most popular methods of transportation in the world, particularly for passengers traveling long distances. If you have ever wondered why plane accidents happen, here are the top five reasons:
1. Pilot Error. Statistics indicate that half of all plane crashes are caused by pilot error. That may seem like a very high statistics, but it makes perfect sense when you think about everything that a pilot must do. Pilots must navigate through dangerous weather, respond to mechanical issues and execute a safe takeoff and landing. Some plane accidents are caused when pilots misread equipment, misjudge weather conditions or fail to recognize mechanical errors until it is too late.
Sometimes too, plane crashes happen when pilots become incapacitated during critical points of a flight. In 2005, a Helios Airways flight to Greece crashed because the flight cabin depressurized, incapacitating the entire flight crew. In 1976, a South African AW flight crashed when the captain suffered a heart attack and his first officer couldn't control the plane in time. Some pilot errors can even be the result of mental problems. A flight to Tokyo crashed in 1987 because a pilot who was known to have serious psychological problems put the plane's engines into reverse mid-flight.
2. Mechanical Error. Mechanical errors are the second leading cause of aviation accidents, accounting for 22% of all crashes. Mechanical errors could occur because of a flaw inherent in the aircraft's design or because a mechanical part was not properly installed or maintained. For example, in 1974 a Turkish Airlines flight to France crashed because of a design flaw in the latch of the cargo door. A West African Airways flight to Nigeria crashed in 1955 because a flawed wing design led to metal fatigue cracks and wing failure.
Sometimes, mechanical failure occurs when outside circumstances damage the plane. Outside forces such as birds flying into aeroplane engines have also been known to cause mechanical failures. For example, in 1962 a United Airlines flight crashed because a single swan that tore off the plane's left horizontal stabilizer struck it. Birds have caused at least seven plane crashes around the world to date.
3. Weather. 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. Aviation accidents have happened because lightning caused electrical failure, because it ignited fuel tanks and pipes, and even because the flash itself caused temporary blindness.
But even milder weather conditions can cause plane crashes. During a flight to Lebanon in 1977, the pilot encountered a thick fog as he prepared to land. Circling back, he retried the landing several more times before fuel ran out and the plane could no longer stay aloft. In 2010, an Indonesian plane carrying 103 passengers crashed when inclement weather conditions caused the pilot to overshoot the runway. The plane skidded into a pool of water at the end of the runway and crashed into a nearby hillside. The impact of the crash caused the jet to break in half.
4. Sabotage. Plane crashes that are caused by sabotage draw the most media attention, but they only account for about 9% of total plane crashes. Some sabotaged flights crash because of hijackers, and of course the most notable examples are the three flights that were hijacked on September 11th. But despite increasingly strict regulations, some passengers still manage to smuggle bombs or firearms onto planes. When they are successful, a single passenger can bring down a jet, killing hundreds of people. Although terrorists, extremists or militia groups are usually responsible for attacks like these, that is not always the case. 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.
This is the reason why our aviation security personnel should be better supervised to perform more thorough and professional screening of everyone entering the secured airside. It is sad to note that there is still a very present, "Madam, what do you have for me?' and "Oga, your people are loyal o" syndrome that seeks gratification from the traveling public occurring everyday at our airports dislodging the seriousness with which security screening should occur each and every time.
5. Other Human Error. 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. Any misstep or failure to follow proper air traffic control procedures can lead to a fatal plane crash. Also, when a plane is loaded, fueled or maintained incorrectly, that's human error too.
One of the more common fatal mistakes caused by humans is something called "fuel starvation" - but this isn't always the result of an improperly filled fuel tank. A Coastal Airlines flight in 1948 crashed because the fuel valves were positioned incorrectly, causing both engines to pull fuel from a single tank. An Air Mali flight crashed in 1974 when a diversion and navigation error caused it to circle the wrong city until it ran out of fuel.
The causes listed above are some of the most common ones, but they are far from the only factors that can contribute to an aviation accident. Given the complexities of air travel and the number of factors that can influence any particular flight, determining the cause of an aviation accident can be challenging. Generally, there is not a single cause for an accident, but a combination of several factors.
Nevertheless, air travel is extraordinarily safe. About 1,300 people died in commercial aviation accidents last year, the highest figure in a decade! Almost half of these were victims of the two incidents involving Malaysia Airlines. There is an additional one in five million chance of being killed during a two-hour flight. On the other hand, sitting in an aircraft protects you from many more common causes of death, such as a car crash or a fall down stairs.
Despite the continued growth in traffic, aviation deaths have been declining. Improvements in aircraft design have reached a stage at which it is almost inconceivable that a major incident will be the result of a mechanical failure. Many modern aircraft models utilize the "fly by wire" technology, which means that a computer mediates every action by a pilot and most of the time aircraft literally fly themselves. The 2009 "miracle on the Hudson" landing was an exceptional feat of skilled aviation -- but as his Airbus landed on the river it was the machine, not the pilot, that had selected the gliding speed and angle.
The dangerous moments onboard an aircraft are when the pilot is overriding the electronic systems. They may do so for good reason but with bad outcomes, as when the crew of Air France 447 from Rio to Paris misjudged their response to adverse weather conditions and lost the plane in the Atlantic; or with malevolent intent, as in the Germanwings incident. Passengers should worry, not that the crew is not in control but that they are.
But another reason modern air travel is reassuringly safe is that investigation into accidents is honest and thorough. This is the behaviour we are entitled to expect in any industry: but it is not what we generally see. The "just culture" of the airline industry is more concerned to encourage openness than to attribute blame, and that concept can and should be transferred to other industries that desperately need it to accelerate development in our country. To avoid mistakes in the future it is first necessary, in any given situation, to undertake a dispassionate investigation and make an honest assessment of the mistakes of the past. The proper time to prepare for an accident or serious incident is before it occurs, and these preparations should be exercised on a routine basis. As we strike to follow due diligence carefully and always, our aviation will grow safer and our passengers will not only trust, relax, seat back and enjoy their flights, but their businesses will thrive and our economy will grow in tandem. It can be a win-win for everyone as it is in other climes.