Piper Arrow IV Turbo Maintenance Manual page 666

GENERAL.
INSPECTION OF EXHAUST SYSTEM. (Refer to Figure 78-1.)
The entire exhaust system, including heat exchange shroud, muffler, muffler baffles, stacks and all exhaust
connections must be rigidly inspected at each 100 hour inspection. The possibility of exhaust system failure
increases with use. It is recommended that the system be checked more carefully as the number of hours
increase, therefore inspection at the 700 hour period, that the exhaust system has been in use, would be more
critical than one in the 100 hour period. The system should also be checked carefully before winter operation
when the cabin heat will be in use.
It is recommended that all airplanes be fitted with a new muffler
at or near the 1000 hour period of which the muffler has been in
use.
Removal of the tail pipe and stacks is required for inspection of the muffler baffle. Remove or loosen all
exhaust shields, carburetor and cabin heat muffs, shrouds, heat blankets, etc., as required to permit inspection
of the complete system. Perform the necessary cleaning operations and inspect all external surfaces for dents,
cracks and missing parts. Pay particular attention to welds, clamps, supports and support attachment lugs, slip
joints, stack flanges and gaskets. Inspect internal baffle or diffusers. Any cracks, warpage or severe oxidation
are cause for replacement of the muffler.
If any component is inaccessible for a thorough visual inspection, accomplish one of the following:
1. Accomplish a submerged pressure check of the muffler and exhaust stack at 2 psi air pressure.
2. Conduct a ground test using a carbon monoxide indicator by heading the airplane into the wind,
warming the engine on the ground, advancing the throttle to full static RPM with cabin heat valves open, and
taking readings of the heated airstream inside the cabin at each outlet (including rear seat heat outlet, if
installed). Appropriate sampling procedures applicable to the particular indicator must be followed. If carbon
monoxide concentration exceeds .005 percent or if a dangerous reading is obtained on an indicator not
calibrated in percentages, the muffler must be replaced.
PIPER AIRCRAFT
PA-28RT-201 / 201T
MAINTENANCE MANUAL
—NOTE—
3G3
78-00-01
Page 78-01
December 1, 1978