The Jet Provost could be a problem.
Yup! Sitting there flying speed and heading on a standard IMC departure from Leeming one day and suddenly noticed that ROC = √sod all.
Things then happened quickly and simultaneously: Bas looked out and saw lots of pretty ice/engine began to vibrate/JPT went off the clock.
RTB for deadstick landing but engine produced enough power for a bit of control just in case but only used it to taxi in.