What was found
A CRACK WAS DISCOVERED IN THE FIREWALL FORWARD DOUBLER. THE CRACK IS LOCATED BEHIND THE "COWL EXIT RAMP- RIGHT HAND" (P/N 0752732-2 SEE MANUFACTURE IPC REV 19 53-10-00 ITEM 241). THE LONGEST SECTION OF CRACK IS 6 INCHES LONG. THERE IS ALSO A SECONDARY CRACK (3/4 INCH LONG) RADIATING OUT FROM THE RIVET HOLE AT THE CENTER OF THE 6 INCH CRACK. ANOTHER SMALL CRACK (3/4 INCH LONG) WAS FOUND JUST OUTBOARD OF THE 6 INCH CRACK DURING RIVET REMOVAL IN PREPARATION FOR REPAIR. THIS AREA IS VERY DIFFICULT TO INSPECT ON A P1 (50 HR) WITH THE LOWER COWLING INSTALLED. IT IS STILL DIFFICULT TO INSPECT WITH THE LOWER COWLING REMOVED ON A P2 (100HR) OR P3 (ANNUAL), BUT IT IS ACCESSIBLE. THERE WAS SUBSTANTIAL DIRT AND OIL BUILD UP IN THE AREA BEHIND THE COWL EXIT RAMP MAKING THE AREA HARDER TO INSPECT.