Investigation Summary
Flight 253 departed New York late on June 19. Approximately 80 minutes into the flight, the crew reported a runaway propeller on the number 2 engine (inboard port). Unable to feather the propeller, Captain Luis Plata declared an emergency and began a return to Idlewild. The aircraft was escorted by a U.S. Coast Guard Grumman Albatross and an Eastern Airlines flight. As the aircraft descended off the New Jersey coast, the crew received clearance to dump fuel. Witnesses in the escort aircraft saw the fuel ignite immediately. The official investigation suggested that severe vibrations from the overspeeding propeller caused structural failure in the wing or fuel lines, allowing fuel to contact hot engine gases. However, subsequent litigation introduced evidence that the propeller may have separated and sliced through the fuselage, igniting the center fuel tank.
Final Conclusions
The investigative board concluded that the most probable cause was structural damage to the starboard wing caused by vibrations from the runaway number 2 propeller. While the cause could not be determined with absolute certainty, the board assumed that vibrations caused an internal wing attachment to break behind the number 3 engine, creating a leak between the fuel tank and the dump chute. When fuel jettisoning began, the leaking fuel ignited upon contact with hot exhaust gases from the number 3 engine. The resulting fire caused a total loss of control and the disintegration of the aircraft.
Video Analysis
No video analysis linked for this case file yet.
Systems & Failure Modes
The system failed to rotate the blades of the number 2 engine to a pitch that would stop them from spinning in the airstream.
The system failed to rotate the blades of the number 2 engine to a pitch that would stop them from spinning in the airstream.
Designed to lighten the aircraft for emergency landings, the system released fuel that ignited during the descent.
Designed to lighten the aircraft for emergency landings, the system released fuel that ignited during the descent.
Interesting Facts
- 01At the time of the crash, it was the deadliest accident involving a scheduled commercial flight.
- 02The aircraft was named 'Rafael Urdaneta'.
- 03The wreckage was located in approximately 120 feet of water using sonar on June 30.
- 04The Venezuelan government requested that recovery operations be halted on July 6, 1956.
- 05A second LAV Flight 253 crashed just six months later in November 1956, killing all 25 on board.
Safety Actions & Advisories
Propeller Pitch-Lock Mandate
In May 1959, the FAA made propeller pitch-lock mechanisms mandatory on U.S. piston-engined transport aircraft to prevent blades from opening further during an overspeed.
Known Controversies & Unanswered Questions
Ignition Source Dispute
Reference ↗While the official board cited vibration-induced structural failure near the number 3 engine, expert testimony in subsequent civil litigation suggested the number 2 propeller separated and sliced through the fuselage, igniting the center fuel tank.