[Porsche-O-Phile]

Model rockets with small baggies filled with the incindiary of your choice (gasoline, gunpowder, whatever) above the engine so that when the "parachute charge" goes off (normally pushes the nose cone off & deploys the chute) it results in ignition of the incindiary material.

Side note: When using gasoline-filled baggies in this manner, make sure the engine selected for the rocket is powerful enough to get the rocket HIGH in the air. Gas is heavy and an underpowered engine MIGHT possibly result in a low-altitude explosion replete with burning gasoline/napalm raining down on the launchers' heads causing them to run for cover as the field they're standing on catches fire. . . Just maybe.