The Tornado was flying at about 483mph near Headon airfield in Nottinghamshire when it passed 300ft beneath the microlight, a UK Airprox report said.
Alarmingly, it also emerged the civilian airfield was marked in the wrong spot on military maps by half a mile. The near-miss on 2 October 2015 was reported by the microlight pilot.
The report said that the Tornado pilot was "entitled to fly where he had", but said he should have left more room for manoeuvre.
The pilot had failed to spot the smaller aircraft as he passed 500ft (152m) above the ground.
The Airprox report ruled it was a Category A incident because "a serious risk of collision" existed.
"The Tornado pilot would probably have been better placed to have remained at height until further north due to the myriad of small airfields and avoidances in that particular area," the report stated.
"Essentially, the Tornado pilot was threading the gap very finely between these airfields and… he had left very little margin for error and would have been wiser to have allowed himself much more room to manoeuvre."
on light aircraft after it emerged the microlight was not equipped with one.
It also said the Airprox board was "heartened to hear from the military low-flying representative that the military charts were being amended to place Headon in the correct position".
JULIAN BRAY +44(0)1733 345581 Aviation Expert, Journalist & Broadcaster, Aviation Security & Airline Operations Expert, Travel / Maritime & Cruise Industry, NUJ, EQUITY, LIVE ISDN LINK, Broadcast ISDN COOBE ++44 (0)1733 345020 e&oe Old faithful NOKIA: 07944 217476 www.aviationcomment.com