While near misses are the subject, had an unidentified military jet pass maybe 50' in front of me from left to right at 1500' near Ashford, Kent, at exactly the same altitude while in a H300. Also over the Long Island Sound in a plank had another one miss by 100' or so. Taught me all about head down in the cockpit - i'll never forget them ! That's 2 in 500 hours ! God knows how many you old timers must have had and not even known about them ! Safe flying !