Bruce R wrote:

"Maple1" wrote in message
...

What's the dirty smudge coming off the left wing root area?


Bruce



APU exhaust


Could you clarify for me item/purpose etc for it? Not being a jet
jockey I am clueless..............no comments from the Peanut Gallery
please.


Bruce


It is the Auto Power Unit sort of like the starter on your car It is a
timy turbine unit. They start it and it has enough power to get the
systems going and turn the main turbine to get the engine going. Prior
to the Apu they used an explosive charge to get the turbine spining Very
cool start up but a pain in the tail pipe.
LOL