The US Air Force has advised British-based pilots to keep cockpit windows clean to avoid mid-air collisions with civilian aircraft.
A reference sheet for USAF pilots at RAF Lakenheath states they must keep their windscreens clean and "consciously note how much time you spend looking outside the cockpit".
The appeal comes after a spate of near misses between military and civilian aircraft.
F-15 jets based at RAF Lakenheath were involved in 19 close-call incidents with UK aircraft over the past five years.
One of the most recent events resulted in a F-15 pilot from the Suffolk base receiving praise after identifying a glider with the naked eye.
The Airprox report into the incident described the moment the pilot swiftly acted to avoid a lethal crash over the Black Mountains near Hereford:
“It [the glider] was seen late, about 1km away, and looked to be manoeuvring aggressively, presumably taking avoiding action.
"The fast-jet banked sharply and steeply right, pulled hard and rolled inverted.
"He then continued to roll right until erect and then continued after the first jet in a south-easterly direction.
"There was no need for the glider pilot to take avoiding action because of the aggressive action taken by the fast-jet."
The British Glider Association applauded the quick response of the F-15 pilot.
The UK Airprox Board has had more than 1,000 near-misses reported over the past five years, with 360 of those involving British or American military aircraft.
Due to an increased traffic in the sky and smaller civilian aircraft often not being picked up on radar as they lack a transponder, the USAF has urged pilots to use the "see and avoid" method of detection.
Most of RAF Lakenheath’s US aircraft operate on ultra-high frequency radio which cannot hear civilian aircraft which use very high frequency instead.