VTOL

[Zarrok1138]

This might not be possible, but we need to make a VTOL engine that has a mark one part for the engine, BUT does NOT have an exhaust. Instead, you have radially mounted thrusters you add on that can be toggled between VTOL and normal flight. The trick being the thrusters don't produce thrust UNLESS the engine is present.

[SpaceMouse]

Your talking about something like a Harrier? There are a few parts like that. SuicidalInsanity's mk2 pack has some.

[XOC2008]

Yeah but he's not talking about an all in one part but rather two parts.. the engine/intake, and then the nozzles as a separate piece to be added to the craft where you see fit. 
 

You could give the nozzles a custom resource needed to produce thrust, which is only produced by the engine. Therefore, no engine, no thrust.