Convair 340/440 accident at New Haven, Connecticut, 7 Jun 1971

Accident narrative

On June 7, 1971, at approximately 0949 e.d.t., Allegheny Airlines Flight 485 crashed while attempting an instrument approach to Runway 2 at the Tweed-New Haven Airport in New Haven, Connecticut. The Allison Prop Jet Convair 340/440 struck three beach cottages on the northern shore of Long Island Sound at a height of approximately 29 feet above mean sea level. Of the 31 people aboard—26 adult passengers, two infants, two pilots, and a stewardess—28 perished. Two passengers and the first officer survived.

**The flight**

Flight 485 was a regularly scheduled passenger flight from Washington, D.C., to Newport News, Virginia, with en route stops at Groton and New Haven, Connecticut, and Philadelphia, Pennsylvania. The crew consisted of Captain David Gordon Eastridge, who had accumulated approximately 12,207 hours of flying time including 3,600 hours in the Convair 580; First Officer James Alford Walker, who had 4,180 hours with 2,400 in the Convair 580; and Flight Attendant Judith L. Manning.

Due to below-minima weather conditions at Groton and New Haven, the flight's dispatch release was amended to allow it to proceed under Instrument Flight Rules (IFR) to Philadelphia, with Wilmington, Delaware, as an alternate. Additional fuel was added in Washington, eliminating the need for a normal refueling stop at Groton.

**Sequence of events**

The flight departed Washington at 0714. Five minutes later, the crew cancelled their IFR flight plan and proceeded directly to New London under Visual Flight Rules (VFR). Upon arriving in the New London area at approximately 0813, reported weather was below the minima for a VOR approach to the Trumbull Airport at Groton. The flight held "VFR on top" awaiting improvement.

At 0841, the flight requested an IFR approach to Trumbull Airport. Between 0852 and 0909, the crew attempted three approaches, each terminating in a missed approach. Flight recorder data showed that on the first two approaches, the airplane descended to approximately 175 feet m.s.l., and on the third to 125 feet m.s.l., well below the minimum descent altitude (MDA) of 510 feet. The investigation disclosed that the runway environment was not sighted during any of these approaches. Weather conditions deteriorated during these attempts, dropping to an indefinite ceiling of 100 feet and 1/4 mile visibility, though records failed to establish that the crew received this updated information.

After the third missed approach, the flight climbed VFR, circled for five minutes, and requested a contact approach. This was approved after the crew advised that the company was reporting one mile visibility at Groton. The flight landed at 0923. Twenty passengers deplaned, 14 boarded, and cargo was loaded. No fuel was added.

Flight 485 departed Groton at 0933. Westchester Approach Control cleared the flight to descend to 1,600 feet and issued the New Haven weather: sky partially obscured, visibility 1 3/4 miles in fog, wind 180 degrees at 5 knots. At 0948, the New Haven Tower controller advised the flight that the wind was 190 degrees at 5 knots and offered Runway 2 or 20. The flight chose Runway 2, despite a company directive prohibiting downwind landings at Tweed-New Haven.

During the final approach, the captain called "out of a thousand" and commanded landing flaps extended to 40 degrees. The first officer called "500 feet", "Top Minimums", and "Decision Height". After noting the flight had descended through the prescribed MDA of 380 feet, the first officer called out an airspeed of 105 knots and a sink rate of 500 feet per minute. The captain acknowledged and instructed the first officer to "keep a sharp eye out here."

Approximately 18 seconds later, the first officer remarked, "You can't see down through this stuff." The captain responded that he could see the water and could see straight down. The first officer exclaimed that he could see the water too, that they were "right over the water," and "not twenty feet off the water." The descent continued unarrested.

Approximately 3.5 seconds later, the first officer said, "Hold it," immediately followed by impact with the cottages. The first officer later stated in deposition that he saw the building appearing out of the fog and that there was no attempt by the captain to arrest the descent.

**What the investigation found**

The airplane came to rest 270 feet north of the initial impact point and sustained near total destruction by an intense fire that developed immediately. The landing gear was extended and the wing flaps were at 40 degrees. Examination of the wreckage revealed no evidence of a pre-impact control system failure or malfunction within the powerplants, which were operating at approximately 1,600 horsepower at impact.

Both altimeters were recovered. The captain's was set to 29.34 inches and the first officer's to 29.96 inches. Filter screens on both were partially obstructed by an anti-seize compound, but tests showed this caused a maximum lag of only 20 feet, which the Board concluded was not a causal factor.

Weather analysis indicated a dense fog layer based at the surface with a top at approximately 400 feet m.s.l. Over the water at the accident site, an indefinite ceiling of less than 100 feet existed, with horizontal visibility restricted to less than 50 feet.

The Board analyzed the captain's decision-making, noting that the flight departed Groton with 200 to 500 pounds less fuel than the 6,000 pounds reported by the crew. The Board believed this slight shortage prompted the captain to accept Runway 2 with a tailwind to save time and fuel, avoiding a refueling stop at New Haven.

The Board also examined the interaction between the pilots. The captain was described as an authoritarian who enjoyed absolute command, while the first officer appeared quiet and submissive. The first officer indicated he had thoughts of taking over control but felt it was better to have one person flying the airplane than two fighting over it. The Board noted that the first officer's actions did not fully comply with prescribed procedures regarding callout terminology, but recognized the dilemma of questioning a captain's command authority. The Board also reviewed a pilot contract provision that rewarded flying ahead of schedule with bonus pay, noting such provisions might not be in the best interest of safety, though it was difficult to relate this directly to the New Haven approach.

The accident was classified as survivable. The fuselage structure remained sufficiently intact to preclude traumatic injuries to the occupants, except in the cockpit area. Autopsy and toxicological studies showed the passengers died of chemical asphyxiation and thermal injury. The stewardess, who died of chemical asphyxiation, also suffered fractures to a rib, clavicle, and vertebra. Fifteen of the 28 fatalities were found near the rear service door, which was found in the latched position. The Board noted that the stewardess's injuries likely incapacitated her, and that passengers in the smoke-filled darkness would have found it difficult to read the instructions to open the door. The airline was operating under an exemption that allowed the flight to carry only one flight attendant instead of the normally required two. The Board believed the probability of survival might have been substantially increased if an additional cabin attendant had been aboard.

**Probable cause**

The National Transportation Safety Board determined that "the probable cause of this accident was 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."