Accident Douglas DC-4 NC30046,

ASN Wikibase Occurrence # 336968

Date:	Thursday 29 May 1947
Time:	19:05
Type:	Douglas DC-4
Owner/operator:	United Airlines
Registration:	NC30046
MSN:	18324
Year of manufacture:	1944
Total airframe hrs:	5950 hours
Fatalities:	Fatalities: 43 / Occupants: 48
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	New York-La Guardia Airport, NY (LGA) - United States of America
Phase:	Take off
Nature:	Passenger - Scheduled
Departure airport:	New York-La Guardia Airport, NY (LGA/KLGA)
Destination airport:	Cleveland Municipal Airport, OH (CLE/KCLE)
Investigating agency:	CAB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
A Douglas DC-4, operated by United Air Lines, was destroyed in an accident at New York-La Guardia Airport, New York, USA. Five of the 48 occupants survived the accident.
The DC-4, named "Mainliner Lake Tahoe", was ready for takeoff at 19:04 hours local time. The tower operator asked whether the flight wished to wait out a storm on the ground. The captain answered. "I'll take off." The tower then advised the flight: "Cleared for immediate takeoff, or hold; traffic on final approach north of Riker's Island." Flight 521 rolled onto runway 18, and accelerated for takeoff immediately. The captain applied back pressure to the control column but the controls felt heavy and the aircraft did not respond. The captain decided to discontinue takeoff.
About 1,000 feet from the south end of the runway he applied brakes, ordering the co-pilot at the same time to cut the engines. A ground-loop was attempted by heavy application of left brake. The aircraft, however, proceeded to roll straight ahead. Then, with both brakes locked it continued over the remainder of the runway, crashed through the fence at the airport boundary, and half-bounced, half-flew across the Grand Central Parkway. The aircraft finally came to rest immediately east of the Casey Jones School of Aeronautics, a distance of 800 feet from the end of runway 18 and 1,700 feet from the point at which brakes were first applied. It was almost immediate enveloped in flames.
Investigation revealed that the gust locks on the plane had been altered, permitting it to remain locked even after removal of the gust lock warning tape.

PROBABLE CAUSE: "The Board determines that the probable cause of this accident was either the failure of the pilot to release the gust lock 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."

Accident investigation: