Well said Volfy,

I put an on board glow into our trainer. It is a Senior Falcon tail dragger with a Saito 56 (engine #3 we have worn out 2 Saito 50s in this plane already) .

It is nice to flip the switch on ,drop the throttle to idle and kick it over. It will idle at 1800 Rs till the tank (16 ounces) is dry. We teach students to fly slow,VERY slow. Never have to worry about tinkering with outboard batteries at all. The plane is used by many and we don't have too hot glow drivers popping the glow plug either. When the throttle is advanced the glow is turned off automatically,another plug saver ! The weight in a plane like this is nearly a non issue and a worthwhile trade off.

Heck an Enya #3 will darn near last as long as the engine now