Demo P-51 and Spitfire Top Speed

[David603]

Easily go past 400mph is probably overstating performance, since the Mustang D had a top speed of around 390mph at low level. The weight of the rockets will also be slowing you down.

However 250mph does seem rather low, so here is a little experiment to try. Get up to a decent altitude, and then dive until you do reach 400mph. Then see if you can hold this speed in level flight. If not, see what speed you can maintain.