What was found
CREW REPORTED A BANG TYPE NOISE HEARD WHEN POWER WAS APPLIED FOR TAKEOFF. REPLACED THE PRESSURIZING AND DUMP VALVE. OPS CHECK GOOD. SHOP TEST SHOWED NO INTERNAL FAILURE TO THE P AND D VALVE.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
CREW REPORTED A BANG TYPE NOISE HEARD WHEN POWER WAS APPLIED FOR TAKEOFF. REPLACED THE PRESSURIZING AND DUMP VALVE. OPS CHECK GOOD. SHOP TEST SHOWED NO INTERNAL FAILURE TO THE P AND D VALVE.