The Britannia plane was carrying 234 holidaymakers to Cyprus

In another AAIB report released on Wednesday, an Aberdeen helicopter crew has been blamed for a "serious incident" in July last year.

In that incident a British Airways Boeing 737 carrying 102 passengers had to abort take-off at Aberdeen Airport.

The report says the pilot of the Gatwick-bound flight managed to stop 100 metres from the hovering helicopter, after the crew of the latter misinterpreted instructions from air traffic control.

Missed call

In the Daventry incident, the report says the F15 was one of two from the USAF base at Lakenheath in Suffolk that had been carrying out a formation flying exercise.

The pilot of the second plane had not responded to the call to climb from 10,000ft to 11,000ft in thick cloud.

He and his colleague then noticed their radar showed the other F15 was above them and they began discussing it, said the report.

This led to them missing "at least two other transmissions" that might have led them to realise they had failed to climb to the required height.

Radar recommended

The report said the F15 had not been transmitting a Secondary Surveillance Radar (SSR) code, a normal procedure but one which led to controllers being unaware of the developing situation.

It also rendered high-tech collision avoidance systems inoperable.

The report said if these systems could have been used, they could have turned a "near disaster" into a "disconcerting, but relatively low risk, loss of separation."

It recommended that the Civil Aviation Authority and National Air Traffic Control Services bring in procedures to ensure that aircraft operating in formation use SSR.