Alan George/LONDON

Relatives of passengers killed in July's Trans World Airline (TWA) Flight 800 crash in which 230 people died when a Boeing 747-100 crashed off Long Island, New York, plan to sue the airline and the Boeing company for compensation, says their lawyer.

The move follows investigations, which started when it was found that the crashed aircraft was one of several 747s sold to the Iranian air force by TWA in 1975. The aircraft was repurchased by TWA 12 months later, but not before one of its sister aircraft had crashed near Madrid as a result of an explosion in a fuel tank.

"Our present expectation is that we shall be filing suit rather soon against Boeing and TWA", says Lee Kreindler, who represents the families of 23 victims. Kreindler's New York firm, Kreindler & Kreindler successfully handled the claim against Pan-American Airways by relatives of the Lockerbie bombing victims.

Investigators have explored a variety of possible causes, including terrorism, but with almost 90% of the wreckage recovered no evidence has yet been found to substantiate whether it was a bomb, missile or mechanical failure, which caused the crash. Weather at the time of the crash was good.

It is thought, however, that a key element in the disaster was an explosion in the aircraft's centre fuel tank. Kreindler is exploring the possibility that the explosion might be linked to the earlier disaster.

On 9 May, 1976, a 747 freighter in service with the Iranian air force exploded and crashed while approaching Madrid Airport during a thunderstorm. An investigation determined that the aircraft was struck by lightning while descending through 10,000ft (3,500m). Almost immediately there was an explosion in the No 1 fuel tank which substantially damaged the left wing. The flight continued for 54s until the wing failed. It is believed that the explosion resulted from the ignition of fuel vapour in the ullage of the tank in the immediate vicinity of a motor- driven fuel valve. Since that loss, the US Federal Aviation Administration has issued Airworthiness Directives (ADs) to modify the fuel systems of 747s. These include:

AD 76-14-06, effective June 1976, was to "verify the existence of a clear drain path through each vent/drain hole" between fuel tanks to "prevent accumulation of fluids";

AD 77-12-07, effective from June 1977, intended "to prevent loss of control of fuel shutoff, cross feed and required fuel-management capability'";

AD 79-06-02, which took effect on April 1979, intended "to prevent abrasion of fuel tank boost pump electrical wires",

AD 79-20-11, which became effective October 1979, intended "to improve the lighting protection design of the fuel system";

AD 91-03-13, effective 11 March, 1991 intended "to verify proper application of the centre wing fuel tank secondary fuel barrier and prevent fuel or fuel vapours from entering the cargo or passenger compartments".

There is a history of structural problems and leaking fuel tanks with this type of aircraft, alleges Kreindler.

Source: Flight International