Service difficulty report · Muffler · Piper PA28140

Difficulty date
February 14, 2008
Submitted
February 15, 2008
Operation
General aviation
Make and model
Piper PA28140
Aircraft time
6,891 hours
Engine
Lyc O320E3D
Propeller
Snsnch 74DM
Part
Muffler
Part number
9948200
Part serial
287525155
Condition
Damaged
Location
Engine
Stage of operation
IN
How discovered
9
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN)FOUND OVER THE PAST YEAR THAT USING PRESSURE TESTING VS VISUAL HAS CAUGHT MANY PIN HOLE LEAKS IN THE MUFFLER. IN THE PAST WE WERE FINDING LARGE CRACKS IN BEHIND WHEN WE PRESSURE TESTED EVERY 200 HOURS WHICH YOU COULD NOT SEE VISUALLY SO WE BEGAN PRESSURE TESTING ALL THE TIME VERSUS VISUAL. ALSO FOUND THAT AFTER INSTALLATION OF NEW EXHAUST, PIN HOLES BEGAN TO SHOW BETWEEN 800-1000 HOURS LATER AND THEN PIN HOLES WOULD BEGIN TO SHOW EVERY 100 HOURS AFTER THAT. REALIZED THAT IF WE HAD NOT PRESSURE TESTED THE SYS, WOULD NOT FIND THE PIN HOLES AND WE WOULD END UP WITH A MAJOR REPAIR 100 HOURS LATER. SO WE NOW PRESSURE TEST THE EXHAUST SYS EVERY 100 HRS COMMERCIAL AND ANNUALLY WITH PRIVATES. THIS HAS LOWER THE OVERALL REPAIR COST AND ALSO CREATED A SAFER ENVIRONMENT. (TC NR 20080215003)

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