Pilots based at RAF Lakenheath are being urged to keep their cockpit windows clean in a bid to avoid any mid-air collisions with civilian flights.

It comes after the US Air Force’s F-15 jets were involved in 19 near-misses with United Kingdom aircraft in the past five years.

Latest statistics from the UK Airprox Board – which works to improve air safety in the UK, helping the aviation industry to learn and apply the lessons learned from near misses in UK airspace – details incidents in which military aircraft have come close to mishaps with civilian aircraft.

One such incident involved an F-15 pilot from Lakenheath base, home to the US 48th Fighter Wing, avoided a collision after spotting a glider by eyesight rather than relying on his radar.

The UK Airprox Board found the incident in April took place when a pair of F-15s on a low-flying manoeuvre came close to the glider over the Black Mountains. Reports of the incident said the glider had not been located by the radar instruments. A collision was avoided because it was seen by the F-15 pilots, who changed course.

USAF experts say one of the difficulties is that smaller civilian aircraft are not equipped with the necessary signal transmitting devices for their locations to be picked up on radar.

Military aircraft have been involved in near misses with civilian aircraft more than 60 times in three of the past four years.

There are more than 15 such incidents involving just military planes.

One such disastrous incident was reported in January when two RAF Lakenheath F-15s were involved in a near-miss with an RAF tanker aircraft. UK Airprox Board reports show the aircraft came within 50m of each other.

Lakenheath pilots have been advised to keep a look-out, keep windscreens clean, and to “scan the airspace” around them.

The USAF said its pilots were trained to fly in a “vigilant state” and that safety was always a priority.

Air force officials said while the UK airspace was a “busy and complex”, the USAF was “confident the risk of airprox (air proximity) events is minimized by our continuous training, consistent focus on flight safety and our direct communication with Royal Air Force and civilian air traffic control services”.