What is the highest altitude ever seen here on any of the flights tracked? What have you the user seen?
TIA!
Brian
All I found:
http://flightaware.com/live/flight/N75XP
http://flightaware.com/live/flight/N389QS
http://flightaware.com/live/flight/N508RN
I know there’s ones WAY higher, but that’s all I’ve seen… 
I’ve had a LJ25 at FL510 before…
I knew it would be you or dami next.
When I was an ATC’er I saw a altitude change 200 feet a sweep 400 knots +/- across the ground over Oklahoma then Kansas. Leaving 75,000 we started watching it.
990… 992… 994… 996… 998… —… —… —
SR-71’s were still flying in those days.
NASA 926 (926NA) regularly gets up in the high FL400’s and even high FL500’s. I know the last couple flights were filed (maybe flown) as a T-38 but the N number is a WB-57 Canberra.
If I can express to you in words how much of a Lockheed fan, I would attempt to. I can’t even imagine…
Not fair- that’s unmanned
Kinda my thoughts. If I can’t look out the side from it and say “Dang we’re up there today!!” at that altitude, where’s the fun? 8) 
Where’s HAISR to shed some light on this topic?
He’s at FL600, trying to type with those bulky gloves on his hands!
Not quite the reaching the stratosphere like the jet jockeys but hey what can one expect from 180 ponies!
DAMN-look at that Airspeed! you’s bout to stall that puppy
I’ve flown with guys that taxi that fast…
John in Saudi
Ohhhhh…I m sorry Allen…but thats funny!! Flyboy and Pj beat me to it man…I would ve taken the picture on the descent to 10k not “trying” to reach it! They’re gonna flame you for that one!!!
Allen- You also need to put a little lead in that right foot. MORE RIGHT RUDDER
I was waiting for somebody to note that! 