TWA Flight 800 was a Boeing 707

Boeing 707

The Boeing 707 is a four-engine narrow-body commercial passenger jet airliner developed by Boeing in the early 1950s. Its name is most commonly pronounced as "Seven Oh Seven". The first airline to operate the 707 was Pan American World Airways, inaugurating the type's first commercial flight on...

 that crashed during take off on runway 25 at Leonardo da Vinci-Fiumicino Airport, Rome

Rome

Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...

 at 13:05 GMT on a flight to Athens International Airport

Ellinikon International Airport

Ellinikon International Airport , sometimes spelled Hellinikon was the international airport of Athens, Greece for sixty years up until 2001 when it was replaced by the new Athens International Airport. It is located south of Athens, and just west of Glyfada...

, Greece

Greece

Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

on 23 November 1964. As the Boeing 707 was at 80 knots, the instruments for No. 4 engine indicated zero thrust and the thrust reverser deployment light for No. 2 engine illuminated. The crew aborted the takeoff at a speed below V1 at 800-900m down the runway. The aircraft did not slow down as quickly as the crew expected and veered to the right, whereupon No. 4 engine struck a pavement roller. The aircraft caught fire and traveled another 260m before coming to rest. The accident killed 50 passengers and crew on board, with 23 passengers and crew surviving.

Cause

The cause of the accident was an inoperative No. 2 engine reverse thrust system, even though indications in the cockpit were that the reverser had deployed. This was caused by the disconnection of a duct with resulting lack of pressure in the pneumatic clamshell door actuating mechanism. This malfunction allowed the development of considerable forward thrust by No. 2 engine even though the thrust levers for all four engines were in the "reverse" position.