1976 — Apr 27, American Air 625 runs off landing runway, St. Thomas, US Virgin Isl.– 37

–37 Kimura. World Commercial Aircraft Accidents 3rd Ed., 1946-1993, V.1. 4-11-1994, p. 2-18
–37 NTSB. AAR. American Air…St. Thomas, Virgin Islands, April 27, 1976. Dec 16, 1976.

Narrative Information

NTSB: “About 1510 A.s.t. on April 27, 1976, American Airlines, Inc., Flight 625 overran the departure end of runway 9 after landing at the Harry S Truman Airport, Charlotte Amalie, St. Thomas, Virgin Islands. The Aircraft struck the instrument landing system localizer antenna, crashed through a chain link fence, and came to rest against a building located about 1,040 feet beyond the departure end of the runway. The aircraft was destroyed. Of the 88 persons aboard the aircraft, 35 passengers and 2 flight attendants were killed. Thirty-eight other persons received injuries which ranged from minor to serious. One person on the ground was injured seriously.

“The National Transportation Safety Board determines that the probable cause of the accident was the captain’s actions and his judgment in initiating a go-around maneuver with insufficient runway remaining after a long touchdown. The long touchdown is attributed to a deviation from prescribed landing techniques and an encounter with an adverse wind condition, common at the airport.

“The nonavailability of information about the aircraft’s go-around performance capabilities may have been a factor in the captain’s abortive attempt to go-around after a long landing.” (NTSB 1976, 1)

On April 27, 1976, American Airlines, Inc., Flight 625, a Boeing 727-95, N1963, operated as a scheduled passenger flight from Providence, Rhode Island, to Harry S Truman Airport, Charlotte Amalie, St. Thomas, Virgin Islands, with an intermediate stop at John F. Kennedy International Airport, New York.

“Flight 625 departed John F. Kennedy International Airport at 1200 with 88 persons, including 7 crewmembers, aboard. It was cleared to the Harry S Truman Airport in accordance with an instrument flight rules (IFR) flight plan. The assigned en route flight level (FL) was 330. The flight was uneventful during takeoff, climb, cruise, and descent into the St. Thomas area. All required descent checklists were accomplished.” (NTSB 1976, 2)

“The captain stated that, as the aircraft crossed the runway threshold at an estimated altitude of 30 t o 40 f t , he retarded the throttles gradually, and then, when the landing was assured, retarded them against the idle stops. He said the aircraft was aligned with the runway, and he felt comfortable as he began the flare. Shortly there-after turbulence was encountered.

“The captain said that he did not anticipate turbulence “that far down the runway.” He thought the turbulence was encountered about the 1,000- foot aiming point, and this turbulence caused the right wing to drop. He thought that the right flap or wingtip might strike the ground and he made a control correction to level the wings. After he leveled the, wings the first officer told him that the aircraft was high. The captain said the turbulence seemed to buoy the aircraft; however,
after the first officer’s callout he “got it on the ground.”….

“The captain said that, immediately before touchdown, he decided that the aircraft could not be stopped on the remaining runway; therefore, almost simultaneous with touchdown, he called for a go-around, moved the throttles forward to the “straight up” position (the 1.4 EPR position),
and called for 25′ of flaps.

“The cockpit voice recorder (CVR) disclosed that when the captain called for the go-around, he did not order a change of flap setting. Shortly after the captain announced the go-around, the first
officer asked the captain if he wanted 25′ of flap. The captain responded, “Flaps fifteen.” The first officer stated later that 25′ was the correct flap setting for the go-around, and that rather than debate the point, he placed the flap handle in the 25′ detent….

“The captain said that after he placed the throttles to the straight-up position he watched the EPR gauges. He did not see the EPR come up. He then moved the throttles as far forward as he could reach, and he thought that they had contacted the forward stops on the throttle race. He never saw the EPR pointers move beyond about the “5:00 to 5:30 position” on the EPR gauges (1.2 to 1.3 EPR). The captain said that there was no sensation either of power being applied or of aircraft acceleration. He saw they were not “going anywhere,” so he closed the throttles and applied the wheel brakes. He did not recall extending the speed brakes; however, he believed that he “might have actuated the reversers in the very final stages.”….

“The flight engineer stated that, when the go-around was begun, the captain moved the throttles forward and he watched the EPR pointers move to the 1.4 position; however, he could not state if they were moved farther forward because he had turned his head to scan the flight engineer’s instrument panel. When he returned his scan to the forward instrument panel, he noted that the engine instrument indications had not changed, and he thought that there had been an electrical failure. He, again, scanned his electrical panel and found the readings to be normal. He returned his attention to the forward instrument panel and reached forward to place his hand behind the throttles to assist the captain. Before he could reach them the captain pulled the throttles aft against the idle stops.

“The flight engineer’s recollection of the nose gear position and aircraft attitude during the landing roll, the attempted go-around, and the subsequent rejected go-around are similar to the first officer’s.

“The aircraft continued across the 500-foot overrun and struck the ILS localizer antenna and a portion of the airport’s chain link perimeter fence. The right wingtip struck an embankment along the fence and the outboard portion of the wing was torn from the aircraft’s structure. The aircraft crossed a road, which runs parallel to the perimeter fence, and destroyed several automobiles in its path. The aircraft came to rest in a gasoline station and against a rum warehouse. A passenger in an automobile, which was being serviced at the time the aircraft struck the service station, was injured seriously.

“The three controllers on duty in the St. Thomas tower described Flight 625’s final approach as “normal” until it reached the point on the runway where other Boeing 727’s usually touchdown. They described the usual touchdown point as a point about 1,000 ft to 1,500 ft from the runway threshold. At that point, the aircraft appeared to float. The three controllers fixed the initial touchdown point either at or just before taxiway “C”. Taxiway “C” is 3,000 ft from the threshold of runway 9….” (NTSB 1976, 3-6)

“….the aircraft crossed the threshold at an airspeed of 131 knots and an altitude of about 80 feet. The touchdown was calculated to be about 2,800 feet beyond the threshold. At touchdown, about 1,850 feet of runway and 500 feet of overrun were available on which to stop the aircraft. When the captain stated “Let’s go around,” the aircraft was about 3,450 feet beyond the threshold, or 1,200 feet of runway and 500 feet of overrun remained….

“Post-mortem examination of the 35 passengers and 2 crewmembers, revealed that they died of a combination of impact trauma, smoke inhalation, and third-degree burns. All but three of the surviving occupants of the aircraft received various bodily injuries. Their injuries included abrasions, contusions, lacerations, fractures, and burns…”

“Fire erupted immediately after the right wing struck the embankment. The fire emanated from a rupture in the right wing near the fuselage and was fed by aircraft fuel. It spread rapidly through the center section and right wing areas of the aircraft, isolating the separated tail section from the remainder of the cabin area. The cabin area, the inboard sections of both wings, and the interior of the cockpit were eventually destroyed by fire.

“The Virgin Islands Port Authority airport fire department responded to the accident before the aircraft had stopped. The fire vehicles proceeded down the runway onto the overrun. However, the driver of the lead fire vehicle determined visually that the trucks could not follow the path of the aircraft through the fence because of aircraft debris, “live” power lines, and dense smoke from the burning aircraft. The lead vehicle, with two others following, proceeded south along the perimeter fence and bypassed a closed knockdown gate that was blocked by parked automobiles. The three vehicles continued southwest and through an open gate. The vehicles then proceeded to the crash site, on the perimeter road. The first vehicle arrived on the scene about 2 minutes after the accident. The driver of the lead vehicle stated that the approach from the perimeter road placed him on the downwind side of the aircraft and that the dense smoke from the fire limited his visibility and firefighting capability. He also stated that aircraft debris, downed trees, and “live” powerlines prevented the truck from penetrating the accident area. No effort was made to move the vehicle through the impediments and approach the immediate vicinity of the aircraft wreckage. As a result, the lead vehicle was used to fight the fire from a distance of about 160 feet. In addition, only one proximity suit and no air packs were on the vehicle. Without an airpack, the fire could not have been fought in close proximity to the wreckage….” (NTSB 1976, 11-13)

“The accident was partially survivable. The structural integrity of the cabin area was compromised when it broke into three parts during the impact. Black, acrid smoke and intense fire penetrated the forward and center sections of the broken fuselage as the aircraft slid to a stop. The passengers and flight attendants who survived the accident escaped through breaks in the fuselage or through the overwing emergency exits on the left side of the fuselage within an estimated 1 to 1-1/2 minutes after the aircraft came to a stop. The three flight crewmembers escaped through the first officer’s sliding window.

“Several passenger seats broke loose from their mounts. Some were found outside of the immediate fuselage area. Because of the extensive fire damage, the security of all seats and seatbelts could not be determined….” (NTSB 1976, 13)

“Witness observations, crew statements, FDR information, and CVR information all indicate that the aircraft approached the runway in a normal profile which would result in a touchdown 1,000 feet or slightly more beyond the threshold. Instead of touching down, however, the aircraft floated 5 to 10 feet above the runway’s surface. The FDR data indicate that the aircraft floated between 7 and 8 seconds, during which time it would have traveled about 1,500 feet. This correlated with witness observations which placed the touchdown between 2,500 and 2,900 feet beyond the threshold. After touchdown, the captain, who was concerned that he would not be able to stop the aircraft on the remaining runway, decided to execute a go-around maneuver. He announced his intention to go around about 3 seconds after touchdown….” (NTSB 1976, 24)

“After the aircraft has landed, and particularly after a significant period of time with the thrust levers in idle, the engines are likely to be turning at minimum rotational speed. When the decision is made to go around, it will take about 6 to 7 seconds before the engines will accelerate to takeoff power. During at least part of this time, the aircraft will continue to decelerate while traveling down the runway at a high speed. As thrust develops, the aircraft must be accelerated back to liftoff speed. The Boeing Company’s analysis of this situation showed that a go-around initiated at 110 KIAS will require at least 1,912 feet of runway to achieve a liftoff with takeoff thrust. This distance increases to 2,387 feet if the pilot hesitates with the thrust levers at the vertical position.

“An inherent danger in the go-around maneuver is that the pilot will rotate the aircraft to the takeoff attitude before sufficient thrust has developed to counter deceleration. This procedure is likely to increase the distance required to lift off even more than that determined by the analysis.” (NTSB 1976, 25)

“The Safety Board, thus, concludes that a successful go-around could not have been executed when the captain attempted to do so. However, the analysis of the aircraft’s braking performance indicated that, using maximum braking and spoilers, the aircraft could have been stopped in less distance than required for go-around. In fact, after this landing, the captain should have been able to stop the aircraft on the runway and certainly within the confines of the runway overrun.” (NTSB 1976, 26)

“…when the captain realized that a go-around was impossible and that an accident was inevitable…[he] probably reacted impulsively and instinctively to the dangerous situation by applying full wheel brakes but he did not remember the more deliberate means of lowering the aircraft nose, deploying the spoilers, and applying maximum reverse engine thrust to attempt to stop the aircraft. Had the pilot used these deceleration means when he commenced braking at the 700 feet remaining mark, the aircraft might have been brought to a stop within the confines of the airport perimeter. At the very least, a much lower velocity impact would have occurred.” (NTSB 1976, 31)

“The Board believes that intensive training is the most effective means to combat the effects of this emergency mechanism. Had the captain been exposed during training to critical go-around situations and to the maximum performance stopping capabilities of the aircraft by means of flight simulation and lectures, he may have reacted appropriately in this situation.

“In summary, it is evident that the captain could have extracted himself twice from a dangerous situation and could have avoided this accident. His first opportunity was during the turbulence encounter just after passing the 1,000-foot touchdown area; he should have followed company procedures and should have initiated a go-around as soon as he regained control of his aircraft.

“His second opportunity to avoid the accident came when he decided to land the aircraft; he should have applied maximum performance stopping procedures to bring the aircraft to a stop within the remaining runway length. Furthermore, when an accident was inevitable, the captain had an opportunity to lessen the damage to the aircraft and to diminish the impact velocity; at this time, he should have applied maximum performance stopping procedures.

“Thus, while the Safety Board believes that the causal area of this accident involves the captain’s actions before and after the touch-down, his lack of substantive information about the aircraft’s stop or go-around performance capabilities seriously affected his ability to make a proper decision in this situation. The Board is aware that American Airlines’ training procedures have been revised to include these performance factors. An Operations Bulletin (FM2 C-13) was issued on August 16, 1976, and placed in the Flight Manual. The bulletin states that any decision to go-around at St. Thomas should be made and initiated no later than the 1,000-foot touchdown markers.” (NTSB 1976, 32)

Sources

Kimura, Chris Y. World Commercial Aircraft Accidents 3rd Edition, 1946-1993, Volume 1: Jet and Turboprop Aircrafts. Livermore, CA: Lawrence Livermore National Laboratory, Risk Assessment and Nuclear Engineering Group. 4-11-1994.

National Transportation Safety Board. Aircraft Accident Report. American Air Lines, Inc. Boeing 727-95, N1963, St. Thomas, Virgin Islands, April 27, 1976 (NTSB-AAR-77-1). Washington, DC: NTSB, adopted December 16, 1976, 67 pages. Accessed at: http://libraryonline.erau.edu/online-full-text/ntsb/aircraft-accident-reports/AAR77-01.pdf