1956 — Aug 29, Canadian Pacific Airlines flight 307 approach crash, Cold Bay AP, AK– 15
–15 AirDisaster.com. Accident Database. Accident Synopsis 08291956.
–15 CAB AIR. Canadian Pacific Air… CF-CUP, Cold Bay, Alaska, August 29, 1956.
–15 Liefer, G. P. Broken Wings: Tragedy & Disaster in Alaska Civil Aviation. 2003, p. 155.
–15 NFPA. “Large Loss Aircraft Fires of 1956.” Quarterly, Vol. 50, No. 4, April 1957, p. 317.
Narrative Information
CAB: “Canadian Pacific Airlines Flight 307, a Douglas DC-6B, CF-CUP, crashed following a missed approach at Cold Bay Airport, Cold Bay, Alaska, August 29, 1956, at approximately 2045 B. s. t. Eleven passengers, including one infant, and four crew members were fatally injured. Three passengers and four crew members received injuries of varying degree. The aircraft was destroyed by impact and fire.
“Flight 307, a regularly scheduled international flight, departed Vancouver, British Columbia, Canada, at 1347 (1747 Pacific daylight time), en route to Hong Kong, China, with a refueling stop at Cold Bay, Alaska, and an Intermediate stop at Tokyo, Japan. On board the aircraft were 14 passengers and a crew of eight,…
“At approximately 2045 the aircraft was observed to descend from the overcast north of the airport for a landing on runway 14 and cross the field at low altitude to the intersection of the two runways. At this point a shallow left turn was started and the aircraft went out of sight southeast of the airport. Very soon thereafter fire was observed in that direction….
“Examination of the wreckage and ground marks disclosed that the aircraft first struck the ground at an elevation of 10 feet on a heading of approximately 40 degrees magnetic and 4,300 feet east-southeast of the approach end of runway 26. The physical evidence indicates that at the time of impact the aircraft was descending in a slightly nose-down attitude with the left wing down about 15 degrees. Computed ground speed at impact, based on propeller governor settings and propeller cuts in the ground, was approximately 186 knots….
“Examination of the aircraft wreckage disclosed no evidence, as far as could be determined, of an inflight structural failure of the airframe or malfunction of its systems. There was no indication of inflight structural failure or malfunction of the engines, propellers, or their related accessories….
“The Canadian Pacific Operations Manual, according to testimony of the chief pilot, specifies that, in the case of a missed approach, METO (maximum except takeoff) power is applied, the gear is retracted, and the flaps are retracted to 20 degrees for the climbout. METO power of the aircraft involved was 1,900 h. p. and 2,600 r. p. m. The landing gear and wing flaps were determined to be in the up, or retracted, positions at the time of impact.
“Ground witnesses testified that the aircraft, during its pass over runway 14, was flying at an estimated altitude of 100-200 feet above the ground, with the landing gear down, and landing lights on.
“The company dispatcher, standing on the ramp east of runway 14, observed Flight 307 break out of the overcast, appear to be making a landing, and then he heard power applied. He next observed the aircraft turn to the southeast over the intersection of runways 14 and 26 in a shallow climb from its estimated height over the runway of 50 to 75 feet. The dispatcher held a microphone for VHF radio contacts with the flight and was on the point of asking if the pilot wanted the lights switched to runway 26 when he saw fire at ground level.
“The surviving stewardess testified that she saw the runway lights a short time before the crash. None of the crew survivors recalled any aircraft operating difficulties prior to the impact. One flight crew member, who was resting in a crew sleeping compartment, stated that the approach from over the range station did not seem as smooth as usual, the power was changed frequently during the descent, and that the power applied for a missed approach seemed less than normal. He also said that he thought there was a feeling of “sink” just before the ground contact. The duty navigator, who was unable to see either outside or the two pilots because of a blackout curtain between his seat and the pilots, testified that he overheard Captain Tweed say, “No, Phil” when power was being applied over runway 14. He also observed a reading of 160 feet on his altimeter at this time.
“The Cold Bay Airport is located an the Alaskan Peninsula, 572 miles southwest of Anchorage, Alaska. Its elevation is 93 feet. The two runways, 14-32 and 26-8, are 7,500 and 5,000 feet in length, respectively, and their intersection is on the south side of the airport. The control tower was not operative and there was no CAA Communications Station available….
Analysis
“It is probable that the intention of the pilot during the approach was to land on runway 14, a straight-in landing from the inbound overheading of the range station. The breakout, after descending through the overcast, may have been too close in and high and these factors, together with excessive groundspeed due to a quartering tailwind, may have caused the captain to decide to go around.
“Whether the flight intended to turn and climb to 2,700 feet on the north leg of the Cold Bay range, as the missed-approach procedure prescribes, or to circle under the 500-foot ceiling and land on another runway is not known. However, the company dispatcher, who observed the aircraft and was in radio contact with it, thought the decision was for the latter course an he was about to query the flight if they wanted the other runway (26-8) lighted when the crash occurred.
“Considering that very little altitude was gained after the application of power it is probable that a circling approach had been decided upon when the left turn from runway 14 was made….
“It is evident that the aircraft struck the ground while descending in a slight left turn and while all four engines were not operating at the prescribed power settings necessary to execute a missed-approach procedure.
Findings
“A circling approach was initiated during which the wing flaps were prematurely fully retracted…. The Board determines that the probable cause of this accident was the full retraction of the wing flaps at low altitude during a circling approach without necessary corrective action being taken by the crew.”[1] (CAB AIR. Canadian Pacific Air…, Cold Bay, Alaska, Aug 29, 1956.)
Sources
AirDisaster.Com. Accident Database. Accident Synopsis 08291956. Accessed at: http://www.airdisaster.com/cgi-bin/view_details.cgi?date=08291956®=CF-CUP&airline=Canadian+Pacific+Airlines
Civil Aeronautics Board. Aircraft Accident Report. Canadian Pacific Airlines, Ltd., Douglas DC-6B, CF-CUP, Cold Bay, Alaska, August 29, 1956. Washington, DC: CAB, 5-9-1957. At: http://dotlibrary1.specialcollection.net/scripts/ws.dll?file&fn=8&name=*S%3A%5CDOT_56GB%5Cairplane%20accidents%5Cwebsearch%5C082956.pdf
Liefer, G. P. Broken Wings: Tragedy & Disaster in Alaska Civil Aviation. Blaine, WA: Hancock House, 2003.
National Fire Protection Association. “Large Loss Aircraft Fires of 1956.” Quarterly, Vol. 50, No. 4, April 1957. Boston, MA.
[1] Liefer writes: “Why two experienced pilots simply allowed the DC-6 to fly into the ground without being aware of their actions, will never be known.” (p. 162.)