"While objects regularly enter the earth's atmosphere, and some are quite spectacular looking if they make it to lower altitudes, they do not fly up alongside aircraft, make hard lateral maneuvers, and then accelerate away at high speed. And they definitely don't climb away after descending. Pilots see shooting stars more than most and they aren't children who comment on just any pretty sight they see with air traffic controllers. This was clearly a very unusual occurrence as seen from the cockpit.
This UFO Sighting incident, like others we have felt worthy of reporting on before, was also corroborated by multiple aircraft, and in this UFO Sighting case, those aircraft were spread quite far apart. The fact that Speed bird 94 provided a 'close-up' account of the UFO incident while Virgin 76 conveyed a 'wide-angle' account that made this encounter even more compelling." Irish Aviation Authority Investigating UFO Sightings