Two US fighter crews and ground control staff have been criticised in a report after a near-miss with a civilian aircraft over Bedfordshire.
The F-15E Eagles passed about 1,000 yards from the BA plane
The Air Accident Investigation Branch said there was "general confusion" when the F-15E Eagles from RAF Lakenheath in Suffolk passed close to the aircraft.
They were at 21,000ft and above the level to which they were cleared to fly on 27 January 2005.
There were 35 passengers on board the British Airways regional flight.
The captain of BA CitiExpress (now BA Connect) aircraft told air traffic control he had just seen an F15 pass about 100ft below the nose of the Embraer 145 and "no more than about 200 yards ahead, descending," said the report.
The report said the fighters passed within about 1,000 yards of the Embraer.
The AAIB report went on: "Inadequate transmission and acknowledgements of clearances within the formation plus the crews' inability to fly either as a coherent formation or as two independent aircraft during the diversion were major contributory factors to the ensuing general confusion.
"Also poor use was made of the highly sophisticated aids available to the crews in monitoring fuel loads, monitoring ground position and using airborne radar."
The report was also critical of air traffic control at Lakenheath in Suffolk for a communication failure which "contributed to the subsequent radar identification problems".
The two fighter planes were flying from RAF Lakenheath for a close air support training sortie at Otterburn Range near Newcastle upon Tyne.
During the training exercise, both aircraft became low on fuel and decided to divert due to poor weather and air traffic delays at Lakenheath.
'Critically short of fuel'
It was some time after this that the Embraer captain reported to London-based air traffic controllers that a military fighter aircraft had passed close in front of him.
Eventually the two fighter planes landed safely at RAF Valley at Holyhead in Anglesey.
The AAIB report said the decision to divert was left too late.
The report went on: "Because they were critically short of fuel, the (US) aircraft climbed through their cleared flight level, without transponding, entered controlled airspace and conflicted with the Embraer 145."