The black box has failed to record any audio on the doomed flight that crashed into DFO Essendon killing five people.

The Australian Transport Safety Bureau has released its preliminary report into the crash.

Five people, including the pilot Max Quartermain and four US tourists were killed when the plane crashed into the DFO at Essendon shortly after take-off on February 21.

Initially it was thought engine failure was to blame.

The report stresses that further examination is needed but there were no pre-existing faults identified in either engines recovered from the crash site.

The task of finding out what went wrong has been made even harder for investigators, after it was revealed the black box flight recorder failed.