1951 — June 22, Pan American Flight 151 crash near Monrovia, Liberia –13 US of 40

–40 Eckert. “Fatal commercial air transport crashes, 1924-1981.” AJFM&P, 3/1, Mar 1982, Table 1, p53.
–40 UP. “Wreckage of Airliner In Liberia…” Corpus Christi Caller-Times, TX. 6-24-1951, p. 1.
–13 Americans (6 crewmembers and 5 passengers)
–40 US Civil Aeronautics Board AIR. Pan American…Near Monrovia, Liberia, June 22, 1951.

Narrative Information

Civil Aeronautics Board (US) Accident Investigation Report [Pan Am Flight 151, 6-22-1951]:

“The Accident

“Pan American World Airways Flight 151 of June 21, 1951, a Lockheed Constellation L-049, N 88846, en route from Johannesburg, South Africa, to New York, New York, crashed at approximately 0325Z, June 22, about 54 miles northeast of its next scheduled stop, Roberts Field, Monrovia, Liberia. The 31 passenger and crew of nine were all fatally injured and the aircraft was destroyed.

“History Of The Flight

“Pan American’s Flight 151 departed Johannesburg at 0812, June 21, and after a routine flight and scheduled stop at Leopoldville, Belgian Congo, arrived at Accra, Gold Coast, at 2125. Following a mechanical delay which required the changing of several spark plugs and a set of magneto points, the flight was dispatched and cleared to Roberts Field, Monrovia, on an instrument flight plan at 16,500 feet with Dakar, French West Africa, and Accra as alternates. Take-off from Accra was at 2352Z….The gross weight at departure was 89,255 pounds, including cargo, mail, 3,340 gallons of fuel, 31 passengers, and a crew of nine….

“At 0156 Flight 151 reported over Cape Palmas at 16,500 feet MSL, on instruments, and estimated arrival at Roberts Field as 0246….At 0220 Flight 151 requested clearance to descent. Roberts Field radio cleared the flight to descend to 3,000 feet and advised that at 0225 the Roberts Field tower would establish contact on VHF. A clear two-way contact was made at 0225 on 118.1 mcs, at which time the tower gave the flight the local weather and altimeter setting, cleared it to descend IFR over Roberts Range Station, and indicated that Runway 05 was in use….

“At 02555, nine minutes after its ETA at Roberts, Flight 151 was heard calling Roberts Field on VHF 118.1 mcs. The tower responded, repeating the call three times. There was no indication that the aircraft heard the tower, whereupon the tower switched to 3270 kcs and requested the flight to give its current position. There was no reply to this call. Immediately following failure of the aircraft to respond to Roberts tower on 3270 kcs, the Roberts Field high frequency radio-telephone facility established contact advising the flight that they were unable to read it on 118.1 mcs and that the flight should reply to the tower’s call on 3270 kcs. This message was acknowledged at 0301. At 0305 the flight again contacted Roberts tower on 3270 kcs advising that the Dakar radio beacon was interfering with the Roberts Field radio beacon and that they would ‘be back in 15 minutes.’ Roberts tower advised Flight 151 that Dakar would be requested to turn off the beacon and this message was acknowledged. (Because of incoming traffic to Dakar, the beacon there was not turned off until 0410.) At 0315 Flight 151 again called Roberts tower on 3270 kcs and the latter transmitted the latest weather. The flight did not acknowledge this transmission on 3270 kcs but called Roberts tower on 118.1 mcs. Roberts tower then replied on 118.1 mcs but received no acknowledgment. Thereafter, the tower repeatedly called Flight 151 on both 118.1 mcs and 3270 kcs, requesting the aircraft’s position and broadcasting the weather. However, the incomplete contact at 0315 was the last transmission received from the flight.

“At 0410 emergency procedures were initiated at Roberts Field and at 0515 an alert notice was dispatched to appropriate stations that Flight 151 was still unreported and that aerial search would begin at daylight. During the day of June 22 aerial search was conducted but was not successful in locating the missing aircraft. The first definite information received was when a foot messenger arrived from the village of Sanoye at approximately 1430, June 23, with word that in the early morning hours of June 22 an aircraft had crashed into the side of a hill 2.4 miles west of his village, and that everyone on board was killed. Lack of communication facilities between Sanoye and Roberts Field precluded earlier notification.

“The Investigation

“Investigation at the scene indicated that the aircraft struck at high speed in a laterally level and slightly descending attitude at an elevation of 1050 feet MSL, with the wing flaps, landing gear, and landing lights in the retracted position. The wreckage was distributed about a line running 178⁰ magnetic from the point of impact. All major components were found at the scene, and no evidence was found to indicate that any part had become detached prior to impact. An intense flash fire over the entire area of wreckage distribution and several localized fires followed impact, but there was no evidence of any inflight fire.

“The propeller dome settings indicated that all four engine were producing approximately the same amount of power. The cockpit instruments recovered were too severely damaged to give any reliable indications of their readings when the crash occurred. Statements of eyewitnesses and stopped watches which had been worn by occupants of the aircraft indicted the time of impact as approximately 0325. At this time the aircraft had about eight hours of fuel remaining, having departed Accra with over eleven hours of fuel aboard….

“Analysis

“….Although competent personnel at Roberts Field were waiting on the ramp and listening for the arrival of Flight 251, it was never heard either before or after its ETA, 0246. From this it must be concluded that the flight not only failed to overhead the range station, but also never reached the general area of Roberts Field….

“In the absence of any indications of mechanical trouble, there is no logical explanation for the captain’s action in descending without having positive knowledge of the flight’s position. It must be concluded, therefore, that he made this descent with the mistaken belief the flight’s position was such that he could safely descent below the prescribed minimum altitude. There was no known necessity for immediate descent as the flight still had ample fuel to proceed to either of its alternates, Accra or Dakar, and weather at both remained above minimums during the time the flight might have arrived at either point.

“On July 24, 1951, Pan American World Airways made a change in operating procedures and issued the following instructions to all personnel concerned with African flights

Until further notice minimum instrument approach altitude Roberts Field 8,000 feet. Aircraft will lose altitude by three minute shuttles on the southwest Roberts Field range leg reporting each one thousand feet, procedure turn, and range overhead instrument approach shall start from range overhead with visual and aural ‘Z’ marker indications and be executed in accordance with manual procedure with aircraft reporting inbound procedure turn, low cone, field not in sight or missed approach.

“As a result of a survey of the navigational facilities at Roberts Field by the Civil Aeronautics Administration subsequent to the accident, Pan American World Airways operations into Roberts Field were, on August 9, 1951, restricted to FFR [Visual Flight Rules] day operations only….

“Probable Cause

“The Board determines that the probable cause of this accident was the action of the captain in descending below his en route minimum altitude without positive identification of the flight’s position.”

Newspaper

June 23, UP: “Dakar, French West Africa, June 23. (UP) – All 40 persons aboard perished when a Pan American World Airways Constellation crashed into a hill in wilds of Liberia Thursday, reports from the crash scene said today. Ground rescue parties from Roberts Field, Monrovia [where the plane was headed], reached the scene near the village of Sanoghie, about 45 miles away. The giant airliner crashed into a hill tentatively identified by rescuers as Mount Foria. French officials at search headquarters here said no other details were available.

“Thirteen of the 40 victims were Americans – eight crew members and five of the 31 passengers.

“….Pan American and Civil Aeronautics Authority officials flying over the scene said ‘the plane disintegrated and there could have been no survivors,’ according to Pan American officials in New York….

“The missing four-engine liner ‘Republic’ vanished Thursday night en route from Johannesburg, South Africa, after radioing it planned to land at Roberts Field in 15 minutes. Its final destination was New York, where it was scheduled to arrive at 9:15 a.m. (EDT) today.” (UP. “Wreckage of Airliner in Liberia Reveals All Aboard Perished.” Corpus Christi Caller-Times, TX. 6-24-1951, p1.)

Sources

Eckert, William G. “Fatal commercial air transport crashes, 1924-1981.” American Journal of Forensic Medicine and Pathology, Vol. 3, No. 1, March 1982, Table 1.

United Press. “Wreckage of Airliner In Liberia Reveals All Aboard Perished.” Corpus Christi Caller-Times, TX. 6-24-1951, p. 1. Accessed 6-24-2023 at: https://newspaperarchive.com/corpus-christi-caller-times-jun-24-1951-p-1/

US Civil Aeronautics Board Accident Investigation Report. Pan American World Airways, Inc. — Near Monrovia, Liberia, June 22, 1951 (File No. 1-0053). Washington, DC: 12-5-1951. Accessed 6-24-2023 at: file:///C:/Users/Wayne/Downloads/dot_33417_DS1.pdf