What was found
AFTER UNSUCCESSFUL AIR START THERE IS A BURNING SMELL IN THE CABIN. - UPON ENTERING THE PLANE FOUND BOTH PACKS TO BE IN THE ON POSITION WHICH IS INCORRECT FOR AIR START. C/W STANDARD ENG START UP PROCEDURE. AFTER RESETTING CB'S M4 & M5 ON CBP-1. FOUND NO EVIDENCE OF A BURNING SMELL UPON THE SUCCESSFUL START UP OF BOTH THE L/H & R/H ENGS.SUSPECT SOURCE OF BURNING SMELL TO HAVE COME FROM THE HUFFER CART.