Pan Am Flight 526A - Misplaced Pages

1952 aviation accident

Pan Am Flight 526A
Accident
A Douglas DC-4 similar to the accident aircraft
Date	April 11, 1952 (1952-04-11)
Summary	Dual engine failure, forced ditching
Site	18 km (11.3 mls) NW off San Juan-Isla Grande Airport, San Juan, Puerto Rico
Aircraft
Aircraft type	Douglas DC-4
Aircraft name	Clipper Endeavor
Operator	Pan American World Airways
Registration	N88899 (former 42-72398)
Flight origin	San Juan-Isla Grande Airport, Puerto Rico
Destination	New York City-Idlewild International Airport, United States
Occupants	69
Passengers	64
Crew	5
Fatalities	52
Survivors	17

Pan Am Flight 526A, a Douglas DC-4, took off from San Juan-Isla Grande Airport, Puerto Rico, at 12:11 PM AST on April 11, 1952 on a flight to Idlewild International Airport, New York City with 64 passengers and five crew members on board. Due to inadequate maintenance, engine no. 3 failed after takeoff, followed shortly by engine no. 4. Nine minutes after takeoff, the aircraft ditched in rough seas 11.3 miles NW of San Juan Airport, broke apart and sank after three minutes. Panicking passengers refused to leave the sinking wreck. 52 passengers were killed, and 17 passengers and crew members were rescued by the USCG. After this accident it was recommended to implement pre-flight safety demonstrations for over-water flights.

Aircraft

The Douglas DC-4 piston aircraft with four propellers had made its first flight in 1945 and had 20,835 airframe hours.

Accident

On a sunny day with a gentle breeze, Pan Am Flight 526A, a Douglas DC-4 named Clipper Endeavor, took off from San Juan Airport at 12:11 PM on Good Friday of 1952 on a flight to Idlewild Airport, NY (now known as JFK). Sixty-four passengers and five crew members were on board, including Captain John C. Burn, a well-qualified, seasoned pilot, in command.

Just after takeoff, engine no. 3 failed at 350 feet and the propeller was feathered (its blades were turned parallel to the direction of flight to avoid drag) by the flight crew. The pilots decided to return to San Juan Airport, reversed their heading, and managed to continue climbing to 550 feet when engine no. 4 failed as well. With both engines on the right wing inoperable, the Clipper Endeavor was not able to maintain altitude any longer. Captain Burn declared an in-flight emergency and informed the control tower that he planned to attempt a water landing approximately seven miles NNW off Isla Grande.

Fifteen-knot winds whipped up the sea when the Clipper Endeavor ditched into the Atlantic Ocean north of San Juan at 12:20 PM. The rear fuselage broke off behind the bulkhead of the main cabin and the wreckage sank in fewer than three minutes. Survivors later reported that many passengers had survived the initial ditching but had panicked because they feared the rough seas and the possibility of sharks and had refused to leave the sinking aircraft to board life rafts.

Rescue

After having received Captain Burn's emergency transmission, the tower notified the USCG rescue center and a PBY-5A Catalina flying boat under the command of Lieutenant Ted Rapalus was airborne within 6 minutes. The USCG's second PBY was undergoing routine maintenance and had the auxiliary power unit including bilge pump removed. Due to the gravity of the emergency the PBY was removed from maintenance status and under the command of Lieutenant Commander Ken Bilderback airborne within 10 minutes. To assist the rescue on the surface, the USCG buoy tender Bramble with medical personnel on board was launched as well. Two SA-16 amphibious aircraft from the Ramey AFB located at the far NW corner of Puerto Rico were also dispatched.

Together they were able to rescue twelve passengers and all five crew members from the rough seas.

LCDR Bilderback's PBY had 15 survivors on board when it found itself in a dire situation: because of the missing APU and bilge pump the flying boat had taken on a lot of sea water and almost no power left to takeoff. The decision was made to transfer the survivors to the Bramble. Sea conditions worsened and after the successful transfer of all but two teenage survivors LCDR Bilderbeck's only options were to either abandon the flying boat or to attempt to taxi it back on the sea to San Juan Harbor. As they passed Fort El Morro and taxied into San Juan Harbor, people lined the shore cheering the rescuers.

Probable cause

The following causes were found by the investigation:

inadequate maintenance: engine no. 3 was not changed, leading to its failure immediately subsequent to take-off.
faulty engine parts
the pilots' attempt to re-establish a climb without using all available power after the loss of the second engine (engine no. 4). This led to a nose high pitch attitude and rapid decrease of airspeed which settled the aircraft at an altitude too low for an effectual recovery.

In subsequent legal proceedings Captain Burn was exonerated and the fault turned out to be inadequate maintenance and faulty parts.

Aftermath

After this accident it was recommended to brief the passengers about the location and usage of emergency exits and personal flotation devices before flights over open water.
In memory of the lives lost and honoring the rescuers a San Juan resident wrote a ballad.
LCDR Bilderback was awarded his second Air Medal. His co-pilot LCDR Jack Natwig received the Silver Lifesaving Medal for jumping into the sea to successfully rescue a young boy. Air Crew members Bill Pinkston, Jim Tierney, Peter Eustes and Raymond Evans were all commended by the Commandant of the USCG for a job well done.
Pan Am reused the name Clipper Endeavor for both a Boeing 707-321B in 1962 and a Boeing 727-235 in 1980. A Douglas DC-7B was named Clipper Endeavour.

References

^ "ASN Aircraft accident Douglas DC-4 N88899 San Juan-Isla Grande Airport (SIG)". Aviation Safety Network. Archived from the original on 2012-10-13.
^ Accident Details Pan Am Flight 526A Archived 2010-02-04 at the Wayback Machine, PlaneCrashInfo.com Archived 2009-10-05 at the Wayback Machine
^ Accident Description Pan Am Flight 526A Archived 2007-12-01 at the Wayback Machine, PanAmAir.org Archived 2005-08-05 at the Wayback Machine
Accident location map Archived 2011-06-06 at the Wayback Machine, Aviation Safety Net
^ A Tragic Good Friday 1952 Archived 2008-12-03 at the Wayback Machine, by J. R. Lee, AOC, USCG, Retired and Ted A. Morris, Lt. Col., USAF, Retired
^ "1947 - Coast Guard Air Detachment San Juan Puerto Rico Established" Archived 2009-05-05 at the Wayback Machine, United States Coast Guard Aviation History Archived 2009-04-18 at the Wayback Machine
Definition of "airframe" Archived 2011-07-07 at the Wayback Machine, AviationTerms.com Archived 2011-07-07 at the Wayback Machine
^ Pan Am Clipper Names Archived 2015-03-11 at the Wayback Machine, PanAmAir.org Archived 2005-08-05 at the Wayback Machine
Airplane Flying Handbook; see Glossary p. 6 Archived 2006-01-03 at the Wayback Machine, FAA
"Engine Failure During Flight (Chapter 12 pages 21-31)" Archived 2012-09-21 at the Wayback Machine, Airplane Flying Handbook Archived 2007-08-15 at the Wayback Machine Federal Aviation Administration

External links

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History

Accidents &
incidents

Samoan Clipper (1938)
Hawaii Clipper (1938)
Sikorsky S-43 crash (1939)
Flight 1104 (1943)
China Clipper (1945)
Flight 121 (1947)
Flight 923 (1947)
Flight 1-10 (1948)
Flight 151 (1951)
Flight 526A (1952)
Flight 202 (1952)
Flight 845/26 (1955)
Flight 6 (1956)
Flight 7 (1957)
Flight 115 (1959)
Clipper Panama (1959)
Flight 214 (1963)
Flight 843 (1965)
Flight 292 (1965)
Flight 708 (1966)
Flight 799 (1968)
Flight 845 (1971)
Flight 841 (1972)
Flight 816 (1973)
Flight 806 (1974)
Flight 812 (1974)
Flight 1736 (1977)
Flight 830 (1982)
Flight 759 (1982)
Flight 73 (1986)
Flight 103 (1988)

1985 Pan Am strike

Subsidiaries

Pan Am Express, Uraba, Medellin and Central Airways

Category

v t e Airliner accidents and incidents involving ditching
1950s	Pan Am Flight 526A (April 1952) Swissair Convair CV-240 crash (June 1954) KLM Flight 633 (September 1954) Pan Am Flight 845/26 (March 1955) Northwest Orient Airlines Flight 2 (April 1956) Pan Am Flight 6 (October 1956)
1960s	Aeroflot Flight 366 (August 1963) Japan Airlines Flight 2 (November 1968)
1970s	ALM Flight 980 (May 1970)
1990s	Faucett Perú Boeing 727 disappearance (September 1990) Ethiopian Airlines Flight 961 (November 1996)
2000s	Marsa Brega Short 360 crash (January 2000) Whyalla Airlines Flight 904 (May 2000) Garuda Indonesia Flight 421 (January 2002) Laoag International Airlines Flight 585 (November 2002) Tuninter Flight 1153 (August 2005) US Airways Flight 1549 (January 2009)
2010s	Angara Airlines Flight 9007 (July 2011)
2020s	Transair Flight 810 (July 2021)

v t e Aviation accidents and incidents in 1952 (1952)
Jan 19 Northwest Orient Airlines Flight 324Jan 22 American Airlines Flight 6780Feb 11 National Airlines Flight 101Mar 3 Air France LanguedocMar 22 KLM Flight 592Apr 9 Japan Air Lines Flight 301Apr 11 Pan Am Flight 526AApr 29 Pan Am Flight 202Jun 10 Poznań Pe-2 crashJun 13 Catalina affairJun 28 American Airlines Flight 910Aug 12 TAN C-47 crashSep 6 Farnborough Airshow crashOct 7 Habomai Islands RB-29 shootdown incidentOct 26 BOAC Flight 115Nov 22 Mount Gannett C-124 crashNov 28 Tacoma C-54 crashDec 6 Cubana de Aviación Bermuda crashDec 20 Moses Lake C-124 crashDec 30 Luqa Avro Lancaster crash
1951 ◄ ► 1953

Aviation accidents and incidents in 1952 (1952)

Jan 19 Northwest Orient Airlines Flight 324Jan 22 American Airlines Flight 6780Feb 11 National Airlines Flight 101Mar 3 Air France LanguedocMar 22 KLM Flight 592Apr 9 Japan Air Lines Flight 301Apr 11 Pan Am Flight 526AApr 29 Pan Am Flight 202Jun 10 Poznań Pe-2 crashJun 13 Catalina affairJun 28 American Airlines Flight 910Aug 12 TAN C-47 crashSep 6 Farnborough Airshow crashOct 7 Habomai Islands RB-29 shootdown incidentOct 26 BOAC Flight 115Nov 22 Mount Gannett C-124 crashNov 28 Tacoma C-54 crashDec 6 Cubana de Aviación Bermuda crashDec 20 Moses Lake C-124 crashDec 30 Luqa Avro Lancaster crash

1951 ◄ ► 1953

v t e Aviation accidents and incidents in the United States and U.S. territories in the 1950s
1950	Northwest Orient Airlines Flight 307 (March 1950) Northwest Orient Airlines Flight 2501 (June 1950) Myrtle Beach USAF C-46D crash (July 1950) Fairfield-Suisun Boeing B-29 crash (August 1950)
1951	National Airlines Flight 83 (January 1951) Cubana de Aviación Flight 493 (April 1951) United Air Lines Flight 610 (June 1951) United Air Lines Flight 615 (August 1951) Miami Airlines C-46 crash (December 16 1951) Continental Charters Flight 44-2 (December 29 1951)
1952	American Airlines Flight 6780 (January 1952) National Airlines Flight 101 (February 1952) Pan Am Flight 526A (April 1952) American Airlines Flight 910 (June 1952) Mount Gannett C-124 crash (November 22 1952)* Tacoma C-54 crash (November 28 1952) Moses Lake C-124 crash (December 1952)
1953	National Airlines Flight 470 (February 1953) Western Air Lines Flight 636 (April 1953) Delta Air Lines Flight 318 (May 1953) USMC R4Q NROTC crash (July 1953) American Airlines Flight 723 (September 1953) BCPA Flight 304 (October 1953)
1954	Western Air Lines Flight 34 (February 1954}
1955	Cincinnati mid-air collision (January 1955) TWA Flight 260 (February 1955) American Airlines Flight 711 (March 20 1955) Hawaii R6D-1 crash (March 22 1955)* Pan Am Flight 845/26 (March 26 1955) MacArthur Airport United Airlines crash (April 1955) American Airlines Flight 476 (August 1955) United Air Lines Flight 409 (October 1955) United Air Lines Flight 629 (November 1955)
1956	TWA Flight 400 (April 1 1956) Northwest Orient Airlines Flight 2 (April 2 1956) Grand Canyon mid-air collision (June 1956) Trans-Canada Air Lines Flight 304 (July 9 1956) United States Air Force Flight 441/13 (July 13 1956)
1957	American Airlines Flight 327 (January 6 1957) Pacoima mid-air collision (January 31 1957) Northeast Airlines Flight 823 (February 1957) Northeast Airlines Flight 285 (September 1957)
1958	Capital Airlines Flight 67 (April 1958) Capital Airlines Flight 300 (May 1958) Westover Air Force Base KC-135 crash (June 1958) Northeast Airlines Flight 258 (August 1958)
1959	Southeast Airlines Flight 308 (January 1959) The Day the Music Died (February 3 1959) American Airlines Flight 320 (February 3 1959) Capital Airlines Flight 75 (May 1959) American Airlines Flight 514 (August 1959) Braniff International Airways Flight 542 (September 1959) Piedmont Airlines Flight 349 (October 1959) National Airlines Flight 967 (November 1959) Allegheny Airlines Flight 371 (December 1 1959) San Diego F3H crash (December 4 1959)
This list is incomplete. An asterisk (*) denotes an incident that took place in a U.S. territory, including Alaska and Hawaii prior to statehood. 1940–1949 ◄ 1950–1959 ► 1960–1969

18°32′06″N 66°15′05″W / 18.5350°N 66.2514°W / 18.5350; -66.2514

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