Ah, that would explain what flew directly over our house on aug 13th in tight formation, whistling like an old kettle. I discounted vampires as I didn't think there were two left flying. Glad to be proved wrong.
I assume we're in some kind of air corridor, about 3 miles east of the M25 in Essex as we get all sorts of military hardware fly over the top, more than the law of averages would suggest we deserve.
Keep em coming