It is well known that there is a high incidence of Ufo's seen near or prior to the crash of jets and commerical planes. Whether the ufos were the cause of these crashes is still under question, however it is hypothesized that as Ufo's may interefere with the EMF field, this may effect sensitive navigation and propulsion equipment on a plane or jet - temporarily stalling the plane and possibly leading to crashes if not restabilized. Debunkers argue that the ufos are actually just birds which get sucked into the planes engines and cause mechanical failure. - However many pilots dispute this as sightings report actual brightly lit large unidentified craft or small orbs aka ('foo fighters') that follow the planes. The below videos provide examples of this:

An RAF Lighning jet fighter disappears when approacjing a UFO. Pilot was never found after leaving RAF Binbrook in 1970:


CNN & euro tv reports Ufo's caused Jet Crash?


watch as the ufos pass below the Jet loses propulsion and crashes


Jets, Planes and Ufos (no crashes):


old video, no crash but shows how ufos track jets:

The Stirling City ufos revisited for thos who requested