> 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 nightmare: 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.