Oh
JENKINS - you are a wag! (and you weren't exactly supersonic yerself)
The Cadets were using a light aircraft Flight Sim - that's my excuse!
And the maths still works - at 260 kts it would have been 12 minutes, at 520
6 minutes.
But you are right -
- not only do my brains come out of the back of my head above 150 kts, my nose bleeds above 1500 ft .........