> 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