two loud noises, saw unusual lights in the sky not common for the area20:00 two loud noise like a low flying artillary round just overhead. But heard it break through sound barrier then went silent. looked into the sky in the direction of noise but could not see anything looking for lights of a plane. Maybe low flying fast jet but not in a major city near a civilian airfield on black out.At 20:30 saw chevron shaped lights in sky white light on wings, flashing white light on top and steady red light underneath. Lights vanished except for flashing white light, after approx 1 minute. not sure what it was but definately not military as near civilian airfield and did not look like your normal boeing aircraft.