Originally Posted by Scoop

Speaking of records - Once saw 651 KTs groundspeed on the Maddogs military cousin, the USN C-9B. We were flying over SW Japan in the high twenties in March. They turned us about 45 degrees off of the wind and our GS shot up over 600 KTs so when we got another turn almost completely downwind we bumped our speed up to the clacker (.84M) which resulted in a 651 Kt groundspeed. We figure we had close to a 170 KT tailwind.

Anyone have better than 651 KTS Groundspeed? And before all you TACAIR types chime in, I am strictly referring to transport and commercial type aircraft.

Scoop

PS - And yes, we did take a picture of the FMS to prove it later on at the Atsugi O Club.