Mechanical failure has been blamed for the crash of a Tornado jet from RAF Marham more than two years ago.
Both crewmen ejected safely when the Tornado GR4, from 13 Squadron, was destroyed as it went into the River Humber near Brough in May 2002.
The jet was on a low-level training exercise when a fuel fire began in an area where there was no fire detection or suppression system installed.
The crew who survived had one minute and 18 seconds to eject.
The pilot was unconscious when he hit the water and his personal survival pack had been ripped off.
His navigator also found part of his safety equipment missing from his lifejacket.
Both men were rescued and taken to hospital.
The Tornado disintegrated with the force of the impact.
The board of inquiry recommended that the flying control systems needed better protection and that crew safety equipment be redesigned so that it was strong enough to withstand ejection and landing.
The report into the accident comes a day after two crewmen were rescued when another Tornado GR4 from RAF Marham crashed into the North Sea.