Date:	Tuesday 12 May 1959
Time:	16:13
Type:	Vickers 745D Viscount
Owner/operator:	Capital Airlines
Registration:	N7463
MSN:	287
Year of manufacture:	1957
Total airframe hrs:	4180 hours
Engine model:	Rolls-Royce Dart 510
Fatalities:	Fatalities: 31 / Occupants: 31
Aircraft damage:	Destroyed, written off
Category:	Accident
Location:	Chase, MD -   United States of America
Phase:	En route
Nature:	Passenger - Scheduled
Departure airport:	New York-La Guardia Airport, NY (LGA/KLGA)
Destination airport:	Atlanta Hartsfield-Jackson International Airport, GA (ATL/KATL)
Investigating agency:	CAB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
Capital Airlines Flight 75 taxied away from the New York-La Guardia Airport terminal at 15:20, twenty minutes late. The Vickers Viscount took off from runway 22 at 15:29 and climbed to 14,000 feet, and onto the assigned airway Victor 3.
At 16:02 Flight 75 contacted the Washington Center, reporting over Westchester and estimating Westminster at 16:17, with Herndon next. In the same message it advised, "... ah, we've got a pretty good string of thunderstorms along that course ... ah, if we could stay in the clear and stay a little bit south of Westminster, is that O.K. with you?" The center controller replied "Capital 75, that'll be all right and report passing Westminster." The flight acknowledged. At 16:10 the flight advised, "Ah, Washington Center, this is Capital 75, we've reduced to one seven zero knots account rough air." This was the last message from the flight. Just three minutes later the aircraft lost control in an area of severe turbulence and entered a steep descent. The aircraft probably reached an airspeed of 335 knots, which is 15 percent in excess of the Viscount never-exceed speed or about 5 percent in excess of VD, the maximum speed demonstrated in certification. At an altitude of approx. 5000 feet both horizontal stabilizers simultaneously failed downward and separated. Following separation of the right and left stabilizers the aircraft pitched down violently so that all four engine nacelles broke upward from combined inertia and gyroscopic loads. Immediately thereafter both wings were subjected to extreme downloads under which the right wing separated and the structural integrity of the left wing was destroyed. With the nacelles, right wing, and stabilizers gone, drag induced by the left wing yawed the fuselage violently to the left. Forces to the left tore off the vertical fin with portions of the fuselage attached, the latter already weakened when the left stabilizer stub tore away. During the subsequent gyrations the left wing broke up, its fuel cells were opened and the flash fire occurred. At the same time the remaining fuselage disintegrated.

PROBABLE CAUSE: "The Board determines that the probable cause of this accident was a loss of control of the aircraft in extreme turbulence resulting in an involuntary steep descent following which aerodynamic loads from high airspeed, recovery, and turbulence exceeded the design strength of the aircraft."

Civil Aeronautics Board File No 1-005
ICAO Accident Digest Circular 62-AN/57 (120-123)

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