WASHINGTON: Air crash investigators have revealed the operators of a cargo plane which caught fire at San Francisco last week received a threat against an unspecified aircraft a week earlier.

 
But the US National Transport Safety Board says in a preliminary report on the incident that initial investigations have not revealed any indication of an explosive or incendiary device.

 
An ABX Air Boeing 767 cargo plane was substantially damaged after a fire broke out shortly before the flight crew started its engines.

In its continuing investigation to determine the cause of the June 28 fire that burned a hole through the top of the fuselage of an ABX Air Boeing 767 cargo airplane parked at San Francisco International Airport, the NTSB has established that the primary location of the fire was outside the cargo hold in an area just aft of the cockpit. The fire was extinguished by San Francisco Airport Rescue and Fire Fighting, but not before causing substantial damage to the
aircraft. The flight crew of two, who were preparing to start the engines when the fire broke out, escaped from the aircraft without injury.

The NTSB dispatched a team of five investigators to the accident scene. Joining them were representatives from the Federal Bureau of Investigation; the Bureau of Alcohol, Tobacco and Firearms; the Transportation Security Administration; the Federal Aviation Administration; the San Francisco Fire Department; and Airport Rescue and Fire Fighting.

According to the NTSB report, the 21-year-old aircraft was originally configured for passenger operations and modified in 2004 to a cargo configuration by Israel Aerospace Industries (IAI). The Israel Ministry of Transport has designated an accredited representative to the investigation under the provisions of
the International Civil Aviation Organization (ICAO) Annex 13. IAI will serve as a technical adviser to the accredited representative.

NTSB investigators interviewed both members of the flight crew on Wednesday. The cockpit voice recorder and flight data recorder are at NTSB headquarters in Washington where data from each is being analysed.

The NTSB says its team anticipates completing the on-scene phase of the investigation by July 6.