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Date:Monday 7 June 1971
Type:Silhouette image of generic CVLT model; specific model in this crash may look slightly different
Convair CV-580
Operator:Allegheny Airlines
Registration: N5832
MSN: 384
First flight: 1956
Total airframe hrs:33058
Engines: 2 Allison 501-D13
Crew:Fatalities: 2 / Occupants: 3
Passengers:Fatalities: 26 / Occupants: 28
Total:Fatalities: 28 / Occupants: 31
Aircraft damage: Destroyed
Aircraft fate: Written off (damaged beyond repair)
Location:1,5 km (0.9 mls) S of New Haven Airport, CT (HVN) (   United States of America)
Phase: Approach (APR)
Nature:Domestic Scheduled Passenger
Departure airport:Groton-New London Airport, CT (GON/KGON), United States of America
Destination airport:New Haven Airport, CT (HVN/KHVN), United States of America
Allegheny Airlines Flight 485, a Convair CV-580, departed Washington, DC, at 07:14 hours local time on a domestic passenger service to Philadelphia (Pennsylvania) via Groton and New Haven (Connecticut).
Visibility at Groton was poor, with an indefinite ceiling of 200 feet and a visibility in fog of around 3/4 to 1 mile. After three missed instrument approaches, a fourth attempt was made using a contact approach procedure, which resulted in the aircraft landing at 09:22.
Twenty passengers deplaned at Groton, Fourteen passengers were boarded and 713 pounds of cargo were loaded at Groton. The flight departed then at 09:35 for New Haven.
At 09:48, the New Haven Tower controller advised the flight of winds from 190 degrees at 5 knots and offered runway 02 or 20 for landing. Despite a company directive prohibiting a downwind landing at
the New Haven Airport, the flight crew requested an approach and landing on runway 02.
The approach was flown over sea in poor visibility conditions. At the minimum descent altitude of 380 feet no ground features were observed by the crew. Nevertheless, the captain continued the approach. When the copilot observed the water below, he stated to the captain that "we're not twenty feet off the water."
Immediately thereafter the airplane struck three beach cottages located on the northern shore of Long Island Sound, at a height approximately 25 feet above mean sea level, 4890 feet from the displaced threshold of runway 2 and approximately 510 feet to the right of the extended centerline of the runway.
An intense fire ensued immediately upon initial impact and continued to burn to the point of near total destruction of the upper portion of the fuselage and cabin area of the airplane.

The Convair was originally manufactured as a Convair CV-440 and converted to a Convair 580. The plane had flown 8406 hours since the conversion in September 1967.

Probable Cause:

PROBABLE CAUSE: "The captain's intentional descent below the prescribed minimum descent altitude under adverse weather conditions without adequate forward visibility or the crew's sighting of the runway environment. The captain disregarded advisories from his first officer that minimum descent altitude had been reached and that the airplane was continuing to descend at a normal descent rate and airspeed. The Board was unable to determine what motivated the captain to disregard prescribed operating procedures and altitude restrictions and finds it difficult to reconcile the actions he exhibited during the conduct of this flight."

Accident investigation:
Investigating agency: NTSB
Status: Investigation completed
Duration: 1 years
Accident number: NTSB/AAR-72-20
Download report: Final report
Language: English


Controlled Flight Into Terrain (CFIT) - Ground

» ICAO Accident Digest Circular 118-AN/88 (165-186)

Follow-up / safety actions

NTSB issued 14 Safety Recommendations

Show all...


photo of Convair-CV-580-N5832
accident date: 07-06-1971
type: Convair CV-580
registration: N5832
photo of Convair-CV-580-N5832
wreckage distribution chart

This map shows the airport of departure and the intended destination of the flight. The line between the airports does not display the exact flight path.
Distance from Groton-New London Airport, CT to New Haven Airport, CT as the crow flies is 70 km (44 miles).
Accident location: Approximate; accuracy within a few kilometers.

This information is not presented as the Flight Safety Foundation or the Aviation Safety Network’s opinion as to the cause of the accident. It is preliminary and is based on the facts as they are known at this time.
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Convair CV-580

  • 182 built
  • 8th loss
  • 5th fatal accident
  • 2nd worst accident (at the time)
  • 3rd worst accident (currently)
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