United Air Lines Flight 521 was a scheduled

passenger flight An airline is a company that provides air transport services for traveling passengers and freight. Airlines use aircraft to supply these services and may form partnerships or alliances with other airlines for codeshare agreements, in which ...

operated by a

Douglas DC-4 The Douglas DC-4 is an American four-engined (piston), propeller-driven airliner developed by the Douglas Aircraft Company. Military versions of the plane, the C-54 and R5D, served during World War II, in the Berlin Airlift and into the 1960s ...

from

LaGuardia Airport LaGuardia Airport is a civil airport in East Elmhurst, Queens, New York City. Covering , the facility was established in 1929 and began operating as a public airport in 1939. It is named after former New York City mayor Fiorello La Guardia. ...

in New York City to

Cleveland, Ohio Cleveland ( ), officially the City of Cleveland, is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located in the northeastern part of the state, it is situated along the southern shore of Lake Erie, across the U.S. ...

. On May 29, 1947, while attempting to take off on runway 18, the aircraft failed to get airborne, overran the end of the

runway According to the International Civil Aviation Organization (ICAO), a runway is a "defined rectangular area on a land aerodrome prepared for the landing and takeoff of aircraft". Runways may be a man-made surface (often asphalt concrete, as ...

, ripped through an airport fence onto traffic on the

Grand Central Parkway The Grand Central Parkway (GCP) is a 14.61-mile (23.51 km) long parkway that stretches from the Triborough Bridge in New York City to Nassau County on Long Island. At the Queens–Nassau border, it becomes the Northern State Parkway, ...

, and slammed into an embankment, ultimately plunging into a pond and exploding. Ten people escaped the flaming wreckage; only five of them survived. It was the worst commercial aviation disaster in United States history at the time. Its record stood for less than 24 hours before an Eastern Airlines DC-4 crashed near Baltimore, Maryland, killing all 53 aboard.

Investigation

The

Civil Aeronautics Board The Civil Aeronautics Board (CAB) was an agency of the federal government of the United States, formed in 1938 and abolished in 1985, that regulated aviation services including scheduled passenger airline serviceStringer, David H."Non-Skeds: T ...

concluded the report on the accident by citing

pilot error Pilot error generally refers to an Aviation accidents and incidents, accident in which an action or decision made by the Aircraft pilot#Airline, pilot was the cause or a contributing factor that led to the accident, but also includes the pi ...

. The report read: "The Board determines that the probable cause of this accident was either the failure of the pilot to release the

gust lock A gust lock on an aircraft is a mechanism that locks control surfaces and keeps open aircraft doors in place while the aircraft is parked on the ground and non-operational. Gust locks prevent wind from causing unexpected movements of the control ...

before take-off, or his decision to discontinue the take-off because of apprehension resulting from rapid use of a short runway under a possible calm wind condition." Although the board came to the conclusion that pilot error was likely the cause, the May 31, 1947, edition of ''The New York Times'' told a different (albeit preliminary) tale: "The United Air Lines DC-4 that crashed and burned at La Guardia Field Thursday night never got into the air and the

pilot An aircraft pilot or aviator is a person who controls the flight of an aircraft by operating its directional flight controls. Some other aircrew members, such as navigators or flight engineers, are also considered aviators, because they a ...

, after using up about two-thirds of the 3,500-foot runway, was trying to halt his giant craft by braking and ground looping. All night, on-the-scene inquiries by both the company and officials of the Civil Aeronautics Board established these facts yesterday. They agreed also that the wind shift, described by a company official as 'of almost unbelievable suddenness', led Capt. Benton R. Baldwin, the pilot, to decide against proceeding with the take-off, but they differed on whether the pilot had been apprised of approaching wind shifts before the take-off." It seemed, at least early on, the cause may have actually been

wind shear Wind shear (or windshear), sometimes referred to as wind gradient, is a difference in wind speed and/or direction over a relatively short distance in the atmosphere. Atmospheric wind shear is normally described as either vertical or horizontal ...

(although it is referred to as "wind shift" in the article).

References

External links

Aviation Safety Network entry on the incidentReport
of the

PDF
{{DEFAULTSORT:United Airlines Flight 0521 Airliner accidents and incidents in New York City Aviation accidents and incidents in the United States in 1947 521 Accidents and incidents involving the Douglas DC-4 Airliner accidents and incidents caused by pilot error 1940s in Queens LaGuardia Airport 1947 in New York City May 1947 events in the United States