Air accident investigators have urged the Ministry of Defence (MoD) to review procedures after a series of near misses between fast military planes and passenger aircraft.
The most recent incident, described as a "serious airprox" (aircraft proximity), occurred between an RAF Tornado and a helicopter returning to Aberdeen from an oil platform on February 5.
In another case, on October 1 last year, an Airbus A319 approaching Newcastle airport was told to take avoiding action from a military aircraft.
There was another airprox, or near miss, between a Jetstream 32 flying from Teesside to Aberdeen and two military jets south of Aberdeen on June 24 last year.
These and other recent incidents were detailed in an Air Accidents Investigation Branch (AAIB) report which recommended the MoD should review the operation of military aircraft in the north east of the UK.
The AAIB also recommended the Civil Aviation Authority should look at arrangements to ensure civilian aircraft are properly protected from military aircraft in the north east of the UK.
The AAIB report gave details of an incident on April 22 2002, in which the crew of a Dash 8 travelling from Newcastle to Stavanger in Norway reported as an airprox an incident with two Sea Harriers on an air defence exercise 30 miles north east of Newcastle airport.
The report said the pilots of the Harriers had wrongly identified their target and broke off as soon as they recognised it as a civilian aircraft. They had not realised their mistake until they came within visual range.
The report also said that on March 20 2000 an RAF Tornado F3 had come within about 300ft horizontally and 100ft vertically of a Shorts SD-360 aircraft bound for Newcastle.
None of the crew in either aircraft saw the other aircraft until after the point of closest approach.