Ten Plane Crashes That Changed Aviation

Ten Plane Crashes That Changed Aviation
Popular Mechanics David Noland October 13, 2007

Flying in a jetliner is extraordinarily safe: There has been only one
fatal crash in the United States in the past five years, an astounding
record considering that more than 30,000 flights take off every day. How
did flying get so reliable? In part, because of accidents that triggered
crucial safety improvements. Here are eight crashes and two emergency
landings whose influence is felt -- for the good -- each time you step
on a plane.

1956 | GRAND CANYON | TWA FLIGHT 2 & UNITED FLIGHT 718
Upgrade: Improvements of air traffic control system; creation of FAA
The TWA Super Constellation and the United DC-7 had taken off from Los
Angeles only 3 minutes apart, both headed east. Ninety minutes later,
out of contact with ground controllers and flying under see-and-avoid
visual flight rules, the two aircraft were apparently maneuvering
separately to give their passengers views of the Grand Canyon when the
DC-7's left wing and propellers ripped into the Connie's tail. Both
aircraft crashed into the canyon, killing all 128 people aboard both
planes. The accident spurred a $250 million upgrade of the air traffic
control (ATC) system -- serious money in those days. (It worked: There
hasn't been a collision between two airliners in the United States in 47
years.) The crash also triggered the creation in 1958 of the Federal
Aviation Agency (now Administration) to oversee air safety.

1978 | PORTLAND | UNITED FLIGHT 173
Upgrade: Cockpit teamwork
United Flight 173, a DC-8 approaching Portland, Ore., with 181
passengers, circled near the airport for an hour as the crew tried in
vain to sort out a landing gear problem. Although gently warned of the
rapidly diminishing fuel supply by the flight engineer on board, the
captain -- later described by one investigator as "an arrogant S.O.B."
-- waited too long to begin his final approach. The DC-8 ran out of fuel
and crashed in a suburb, killing 10. In response, United revamped its
cockpit training procedures around the then-new concept of Cockpit
Resource Management (CRM). Abandoning the traditional "the captain is
god" airline hierarchy, CRM emphasized teamwork and communication among
the crew, and has since become the industry standard. "It's really paid
off," says United captain Al Haynes, who in 1989 remarkably managed to
crash-land a crippled DC-10 at Sioux City, Iowa, by varying engine
thrust. "Without [CRM training], it's a cinch we wouldn't have made it."

1983 | CINCINNATTI | AIR CANADA FLIGHT 797
Upgrade: Lav smoke sensors
The first signs of trouble on Air Canada 797, a DC-9 flying at 33,000
ft. en route from Dallas to Toronto, were the wisps of smoke wafting out
of the rear lavatory. Soon, thick black smoke started to fill the cabin,
and the plane began an emergency descent. Barely able to see the
instrument panel because of the smoke, the pilot landed the plane at
Cincinnati. But shortly after the doors and emergency exits were opened,
the cabin erupted in a flash fire before everyone could get out. Of the
46 people aboard, 23 died. The FAA subsequently mandated that aircraft
lavatories be equipped with smoke detectors and automatic fire
extinguishers. Within five years, all jetliners were retrofitted with
fire-blocking layers on seat cushions and floor lighting to lead
passengers to exits in dense smoke. Planes built after 1988 have more
flame-resistant interior materials.

1985 | DALLAS/FORT WORTH | DELTA FLIGHT 191
Upgrade: Downdraft detection
As Delta Flight 191, a Lockheed L-1011, approached for landing at
Dallas/Fort Worth airport, a thunderstorm lurked near the runway.
Lightning flashed around the plane at 800 ft., and the jetliner
encountered a microburst wind shear -- a strong downdraft and abrupt
shift in the wind that caused the plane to lose 54 knots of airspeed in
a few seconds. Sinking rapidly, the L-1011 hit the ground about a mile
short of the runway and bounced across a highway, crushing a vehicle and
killing the driver. The plane then veered left and crashed into two huge
airport water tanks. On board, 134 of 163 people were killed. The crash
triggered a seven-year NASA/FAA research effort, which led directly to
the on-board forward-looking radar wind-shear detectors that became
standard equipment on airliners in the mid-1990s. Only one
wind-shear-related accident has occurred since.

1986 | LOS ANGELES | AEROMEXICO FLIGHT 498
Upgrade: Collision avoidance
Although the post-Grand Canyon ATC system did a good job of separating
airliners, it failed to account for small private planes like the
four-seat Piper Archer that wandered into the Los Angeles terminal
control area on Aug. 31, 1986. Undetected by ground controllers, the
Piper blundered into the path of an Aeromexico DC-9 approaching to land
at LAX, knocking off the DC-9's left horizontal stabilizer. Both planes
plummeted into a residential neighborhood 20 miles east of the airport,
killing 82 people, including 15 on the ground.

The FAA subsequently required small aircraft entering control areas to
use transponders --electronic devices that broadcast position and
altitude to controllers. Additionally, airliners were required to have
TCAS II collision-avoidance systems, which detect potential collisions
with other transponder-equipped aircraft and advise pilots to climb or
dive in response. Since then, no small plane has collided with an
airliner in flight in the United States.

1988 | MAUI | ALOHA FLIGHT 243
Upgrade: Retiring tin
As Aloha Flight 243, a weary, 19-year-old Boeing 737 on a short hop from
Hilo, Hawaii, to Honolulu, leveled off at 24,000 ft., a large section of
its fuselage blew off, leaving dozens of passengers riding in the
open-air breeze. Miraculously, the rest of the plane held together long
enough for the pilots to land safely. Only one person, a flight
attendant who was swept out of the plane, was killed.

The National Transportation Safety Board (NTSB) blamed a combination of
corrosion and widespread fatigue damage, the result of repeated
pressurization cycles during the plane's 89,000-plus flights. In
response, the FAA began the National Aging Aircraft Research Program in
1991, which tightened inspection and maintenance requirements for
high-use and high-cycle aircraft. Post-Aloha, there has been only one
American fatigue-related jet accident -- the Sioux City DC-10.

1994 | PITTSBURGH | USAIR FLIGHT 427
Upgrade: Rudder Rx
When USAir Flight 427 began its approach to land at Pittsburgh, the
Boeing 737 suddenly rolled to the left and plunged 5000 ft. to the
ground, killing all 132 on board. The plane’s black box revealed that
the rudder had abruptly moved to the full-left position, triggering the
roll. But why? USAir blamed the plane. Boeing blamed the crew. It took
nearly five years for the NTSB to conclude that a jammed valve in the
rudder-control system had caused the rudder to reverse: As the pilots
frantically pressed on the right rudder pedal, the rudder went left. As
a result, Boeing spent $500 million to retrofit all 2800 of the world's
most popular jetliner. And, in response to conflicts between the airline
and the victims' families, Congress passed the Aviation Disaster Family
Assistance Act, which transferred survivor services to the NTSB.

1996 | MIAMI | VALUJET FLIGHT 592
Upgrade: Fire prevention in the hold
Although the FAA took anti-cabin-fire measures after the 1983 Air Canada
accident, it did nothing to protect passenger jet cargo compartments --
despite NTSB warnings after a 1988 cargo fire in which the plane managed
to land safely. It took the horrific crash of ValuJet 592 into the
Everglades near Miami to finally spur the agency to action. The fire in
the DC-9 was caused by chemical oxygen generators that had been
illegally packaged by SabreTech, the airline's maintenance contractor. A
bump apparently set one off, and the resulting heat started a fire,
which was fed by the oxygen being given off. The pilots were unable to
land the burning plane in time, and 110 people died. The FAA responded
by mandating smoke detectors and automatic fire extinguishers in the
cargo holds of all commercial airliners. It also bolstered rules against
carrying hazardous cargo on aircraft.

1996 | LONG ISLAND | TWA FLIGHT 800
Upgrade: electrical spark elimination
It was everybody's nightma a plane that blew up in midair for no
apparent reason. The explosion of TWA Flight 800, a Boeing 747 that had
just taken off from JFK bound for Paris, killed all 230 people aboard
and stirred great controversy. After painstakingly reassembling the
wreckage, the NTSB dismissed the possibility of a terrorist bomb or
missile attack and concluded that fumes in the plane's nearly empty
center-wing fuel tank had ignited, most likely after a short circuit in
a wire bundle led to a spark in the fuel gauge sensor. The FAA has since
mandated changes to reduce sparks from faulty wiring and other sources.
Boeing, meanwhile, has developed a fuel-inerting system that injects
nitrogen gas into fuel tanks to reduce the chance of explosions. It will
install the system in all its newly built planes, starting in 2008.
Retrofit kits for in-service Boeings will also be available.

1998 | NOVA SCOTIA | SWISSAIR FLIGHT 111
Upgrade: Insulation swap-out
About an hour after takeoff, the pilots of Swissair's Flight 111 from
New York to Geneva -- a McDonnell Douglas MD-11 -- smelled smoke in the
cockpit. Four minutes later, they began an immediate descent toward
Halifax, Nova Scotia, about 65 miles away. But with the fire spreading
and cockpit lights and instruments failing, the plane crashed into the
Atlantic about 5 miles off the Nova Scotia coast. All 229 people aboard
were killed.

Investigators traced the fire to the plane's in-flight entertainment
network, whose installation led to arcing in vulnerable Kapton wires
above the cockpit. The resulting fire spread rapidly along flammable
Mylar fuselage insulation. The FAA ordered the Mylar insulation replaced
with fire-resistant materials in about 700 McDonnell Douglas jets.