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Commercial Airplanes Crash
5 Reasons Commercial Airplanes Crash
PATRICK
J. KIGER
Airline crashes are exceedingly rare events.
In 2018, for example,
according to the Netherlands-based Aviation Safety Network, there were 15 fatal
airliner accidents, resulting in a total of 556 fatalities.
But with 37.9 million flights worldwide.
That works out to a rate of one fatal accident per 2.52 million flights [source: AVN].
But when a plane does go down, despite all the safety features
of modern aircraft and the skill of highly-trained pilots, the flying public
wants to know why it happened.
In the U.S., investigators from the Washington, D.C.-based
National Transportation Safety Board (NTSB) are tasked with sifting through the
wreckage, analyzing critical data from cockpit voice recorders and flight data
recorders — the so-called "black boxes"
— and perusing maintenance records, weather data and communications with air
traffic controllers [sources: NTSB, Davies].
But even after painstaking probes, there isn't always a simple,
clear answer to why these catastrophes occur. Instead, plane crashes often
result from the interaction of a combination of factors, according to NTSB
public affairs officer Keith Holloway.
"While the main cause of
the crash was that the pilot lost control, for example, the weather could have
been a factor in why that happened," Holloway says.
Harro
Ranter, chief executive officer of the Aviation Safety Network, agrees with
Holloway. "In most accidents,
several factors are involved," Ranter says in an email.
"In accident investigation, there is
no such thing as a simple cause like 'pilot error.' There is always more
involved."
Coming up with a list of causes is complicated, because
different agencies and organizations that track crashes don't always describe
them the same way.
But in a 2015
article for The Conversation, British aviation safety expert Simon
Ashley Bennett, director of the Civil Safety and Security Unit at the
University of Leicester, listed five common causes of crashes.
They're similar to the categories
utilized by PlaneCrashInfo.com, a website that has amassed data
on aircraft crashes since the 1920s.
Here's some information on
each of them.
5 Pilot
Error
Modern aircraft are
increasingly technologically sophisticated, and their complexity can sometimes
give humans more opportunities to make mistakes.
According to a 2015 article in
The Conversation, aviation expert Simon Ashley Bennett said in about half of fatal
crashes, errors by pilots are the primary cause of crashes [source: Bennett].
PlaneCrashInfo.com's analysis
of 1,104 accidents between 1960 and 2015 puts the frequency a bit higher, at 58
percent [source: PlaneCrashInfo.com].
A study of 558 mishaps between 1983 and 2002,
published in the journal Aviation Space Environmental Medicine in 2008, found
that the most common type of mistake was carelessness, such as neglecting to
check for hydraulic pressure for landing gear and flaps during a pre-landing checklist.
That accounted for 26.3 percent of crashes ascribed to pilot
error. Flawed decisions, such as making an approach to the airport from
too high an altitude, accounted for 23.3 percent.
Making miscalculations in dealing with forces acting on the plane
accounted for 21.2 percent, while poor crew interaction contributed 11.4
percent. Mishandling wind or runways conditions happened in 7.2 percent of
cases [source: Baker, et.al].
One recent example of a crash attributed to mistakes in the
cockpit was Asiana Airlines Flight 214, which struck a seawall at San Francisco
International Airport in 2013, causing the deaths of three passengers and
numerous injuries to passengers and crew members.
An NTSB investigation
determined that "the flight crew
mismanaged the airplane's vertical profile during the initial approach, which
resulted in the airplane being well above the desired glidepath when it reached
the 5 nautical mile point, and this increased the difficulty of achieving a
stabilized approach," and made other mistakes as well.
"The flight crew was experiencing fatigue, which likely
degraded their performance during the approach," NTSB
wrote [source: NTSB].
Some experts, however, have questioned whether some errors that
are attributed to pilots actually are the result of their inability to overcome
other systemic problems in air transportation, such as poor information and
time pressure [source: DeAngelis].
4 Mechanical Failure
The downside of advanced modern planes is that there's more
technology that can break down, leading some to question whether airliners are
overengineered [source: Popular Mechanics].
Roughly 20 percent of crashes are attributable mainly to things
that go wrong with the plane's equipment [source: Bennett].
PlaneCrashInfo.com puts it
slightly lower, at 17 percent [source: PlaneCrashInfo.com].
One particularly horrific example of a malfunctioning
plane was TWA Flight 800, which exploded in midair and crashed
off the coast of Long Island in 1996, killing 230 people [source: FAA].
While some have suspected a
terrorist bomb or missile strike was responsible, the NTSB determined otherwise
[source: Gray].
Instead, as the FAA's website explains, "the most likely scenario was a combination of a latent fault of
an electronic fuel quantity indicating system component within the fuel tank,
combined with a short circuit or other fault outside of the tank. This scenario
would result in a high-energy electrical arc within the fuel tank that could
ignite the flammable vapors" [source: FAA].
Mechanical problems also can be exacerbated by flight crew
mistakes.
In 1989, for example, one of
the engines of a British airliner began to malfunction, according to a report
by the Air Accidents Investigation Board.
But the flight crew
mistakenly believed that the aircraft's other engine was the one that had been
damaged and shut it down instead.
They didn't realize their
mistake until the aircraft abruptly lost power 2.4 nautical miles (4.44
kilometers) from the runway of their destination. That led to a crash that
claimed the lives of 47 passengers [source: Air Accidents Investigation Branch].
3 Weather
Whenever an airliner goes down in a storm, it's natural to
wonder if the weather had something to do with it.
It turns out, though, that
weather is much more of a hazard for small planes, which have more than 20
times the rate of weather-related accidents per 100,000 hours flown compared to
big jet-powered airliners, and it isn't as big a factor in airline crashes as
you might suspect [source: FAA].
Bennett attributed just 10 percent or so of crashes to bad
weather [source: Bennett].
PlaneCrashInfo.com puts the
number a bit lower, at 6 percent [source: PlaneCrashInfo.com].
For airliners, a 2010 FAA study found that the most common
weather factors contributing to accidents was turbulence, while wind was the
second most common. Airliners didn't have much trouble with other weather
conditions, such low visibility and thunderstorms [source: FAA].
One thunderstorm-related phenomenon that can be very dangerous
to airliners is a microburst, a downdraft — a column of sinking air — that
occurs within the storm and creates high-speed winds [source: National Weather Service].
In 1982, for example, a
microburst that occurred during the takeoff of Pan Am Flight 759 from New
Orleans International Airport caused the plane to crash, killing 145 occupants
of the plane, was well as eight people on the ground [source: NTSB].
Sometimes, the problem with weather is how pilots choose to deal
with it. Sylvia Wrigley, author of the book "Why
Planes Crash," told BBC News in 2014 that she couldn't think of a crash
in which weather was the sole explanation. "But
there can be a situation where the weather puts the aircraft at a higher risk
of going wrong," she explained [source: BBC
News].
One weather-related risk is continuation bias — that is, the
inclination to continue with an existing plan, even if it is inadvisable. Such
bias may lead a pilot to attempt to continue on and reach the destination,
rather than diverting because of weather conditions, sometimes with disastrous
results [source: DeAngelis].
2 Intentional Crashes
Not every air catastrophe is an accident, unfortunately. Bennett
estimated that about 10 percent of crashes are caused by sabotage [source: Bennett].
PlaneCrashInfo.com puts the
number slightly lower, at 9 percent [source: PlaneCrashInfo.com].
Intentional crashes often have been caused by bombs planted
on airliners, such as the explosive device in a suitcase that the FBI says
Libyan agents planted on Pan Am Flight 103, which blew up in the air over
Scotland in 1988, killing 270 people [source: FBI].
Other airliners have been
hijacked and deliberately crashed, such as in the September 11, 2001 attacks on
the World Trade Center and the Pentagon [source: National Security Archive].
Still other airliners have been shot down, such as the Malaysia
Airlines Flight 17, which was downed by pro-Russian separatists in Ukraine in
2014 [source: CNN].
There's also a rare, but even more disturbing, scenario, in which
a suicidal pilot decides to take his life and those of his crew and passengers
by deliberately crashing the aircraft.
The Aviation Safety Network website lists 14 instances of pilot
suicide-by-airliner since 1976 [source: ASN].
That compilation includes a controversial 1990 EgyptAir crash off
the coast of Massachusetts that killed 217 people. The NTSB concluded that the
probable cause was "the relief first
officer's flight control inputs" [source: NTSB].
1 Other Human Mistakes
The remainder of accidents, about 10 percent, are caused by
errors made by humans other than flight crews, such as mistakes made by air
traffic controllers, maintenance engineers and others, according to Bennett [source: Bennett].
PlaneCrashInfo.com found that
10 percent of crashes are caused by "other" factors, a category in
which it includes errors by traffic controllers and ground crew, improperly
loaded cargo, runway obstructions and chance events such as bird strikes, among
others [source:PlaneCrashInfo.com].
Mistakes in the tower can be dangerous. In 1991, for example,
after a collision between a commuter plane and a jet airliner cleared to land
on the same runway killed 34 people, the NTSB eventually faulted the local air
traffic control management for not putting in place needed safety procedures,
and was critical of the FAA for its failure to provide policy direction and
oversight [sources: NTSB, Malnic].
Fortunately, controllers don't make many miscues. A 2013 FAA
study found that U.S. air traffic controllers made
4,394 errors in a year in which they handled 132 million flights. Only 41 of
those miscues were deemed "high risk" mistakes, but the FAA concluded
that seven of them might have resulted in catastrophic accidents [source: Halsey].
Maintenance mistakes also can cause crashes. In 1985, the crash
of Japan Airlines Flight 123 that killed 520 people
was linked to a faulty repair performed years before. That had allowed fatigue
cracks to spread and weakened the bulkhead, which eventually resulted in a
catastrophic failure [source:FAA].
Author's
Note: 5 Reasons Commercial Airplanes Crash
Many
years ago, I was on an airliner that was descending to land at Los Angeles
International Airport, when it suddenly soared back high into the air.
The
pilot came on the public-address system to explain that another jet was on the
runway where we were supposed to land.
It
had been a scary moment, but I was reassured by how the pilot had spotted the
problem and used his skills to keep us safe.
Learn more about airline disasters in "Bracing
for Impact: True Tales of Air Disasters and the People Who Survived Them" by Robin Suerig Holleran. HowStuffWorks picks
related titles based on books we think you'll like. Should you choose to buy
one, we'll receive a portion of the sale.
Patrick Kiger
Patrick J. Kiger has written for HowStuffWorks since 2008 covering a
wide array of topics, from history and politics to pop culture and technology.
He worked as a newspaper reporter for the Pittsburgh Press, and the Orange
County Register in California, where he covered one of the biggest serial
murder cases in U.S. history, and also as a staff writer at Baltimore Magazine.
As a freelancer, Patrick has written for print publications such as GQ, Mother
Jones and the Los Angeles Times, and on the web for National Geographic
Channel, Discovery News, Science Channel and Fast Company, among others. In
recent years, he's become increasingly interested in how technological advances
are altering urban life and the design of cities, and has written extensively
on that subject for Urban Land magazine. In his spare time, Patrick is a
longtime martial arts student and a fan of crime fiction, punk rock and classic
Hollywood films.
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Commercial airliners
crash for all kinds of reasons, but they crash very rarely and airline travel
is statistically very safe.
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Asiana Airlines
flight 214, which crashed in 2013 while landing at San Francisco International
Airport, was blamed on flight crew and pilot error.
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Lightning flashes behind an air traffic control tower at McCarran International Airport in Las Vegas, Nevada. Just 6 to 10 percent of air crashes are related to weather.
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The partially
reconstructed wreckage of TWA Flight 800, which blew up shortly after takeoff from
New York's JFK International Airport in 1996, sits in a hangar at the NTSB
Training Center in Ashburn, Virginia.
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Libyan agents planted
a bomb on Pan Am Flight 103 on December 21, 1988. The plane exploded midair
over Lockerbie, Scotland, killing 270 people.
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The air traffic
control tower at Manchester Airport in the U.K.
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