My 10 year old son got to help start an A320 the other day. We were
boarding and the pilot called us into the cockpit to talk to my son. We
talked shop for a bit and then asked my son if he wouldn't mind
starting the APU and getting the bleed air going (the ground crew were
disconnecting the air cart). He showed him the buttons to press and he
did it. After we took off the Captain got on the speaker and thanked my
son for helping get the plane started!!

-Robert