AD 62-26-05 ACTIVE

62-26-05 PIPER: Amdt. 511 Part 507 Federal Register December 5, 1962. Applies to All Models PA-24 and PA-24 "250" Aircraft.

Compliance required within the next 50 hours' time in service after the effective date of this AD, unless already accomplished.

To preclude hazardous carbon monoxide contamination in the cockpit and engine power loss, caused by cracked muffler heater shrouds, accomplish the following:

(a) For aircraft Serial Numbers 24-1 to 24-2298 inclusive, equipped with channel reinforced muffler P/N's 22594-00, 22594-02 on PA-24, and P/N's 22593-00, 23159-00 on PA-24 "250" installed as service replacements:

(1) Remove the tail pipe, the right-hand exhaust stack, and carburetor heat shroud and inspect for cracks and hot spots. Pay particular attention to the junction of rear cylinder exhaust tube with the stack assembly.

(2) Remove the muffler and muffler heater shroud. Carefully inspect the muffler for visible cracks, particularly in the areanear the tail pipe opening and examine the internal baffle and perforated tube. Submerge the muffler in water and pressure test at 10 p.s.i.

(3) Replace the muffler prior to further flight if cracks, heat deterioration, defects, or wrinkles formed in the perforated tube are observed or if leaks are detected during the pressure test.

(4) Rework the muffler heater shroud by:

(i) enlarging the opening in the shroud in accordance with the Piper template;

(ii) installing the muffler reinforcement tube, P/N 23482-00 using 20 rivets PDR 134A-6, or FAA approved equivalent; and

(iii) installing cover plate P/N 23498-00 using 11 rivets AN 426A3-4, or FAA approved equivalent, in accordance with Piper Immediate Action Service Bulletin No. 210 (Kit P/N 754 484).

(5) Reinstall the muffler exhaust stacks, tailpipe, and air ducts on the airplane.

(b) For aircraft Serial Numbers 24-2299 to 24-3284 inclusive, equipped with channel reinforced muffler P/N's 22594-00, 22594-02 on PA-24, and P/N's 22593-00, 23159-00 on PA-24 "250", except aircraft Serial Numbers 24-2876, 24-2929, 24-2949, 24-2967, 24-2990, 24-3033, 24-3095, 24-3114, 24-3130, 24-3150, 24-3155, 24-3173, 24-3191, 24-3193, 24-3194, 24-3196, 24-3198, 24-3203, 24-3204, 24-3222, 24-3233, 24-3234, 24-3241, 24-3244, 24-3248, 24-3254, 24-3257, 24-3258, 24-3265, 24-3268, 24-3270, 24-3273, 24-3274, 24-3276, 24-3277, 24-3278, 24-3279, 24-3280, 24-3282, 24-3283, which have been modified:

(1) Perform inspections required by (a)(1) and (a)(2), and the replacement required by (a)(3), if necessary.

(2) Install new cabin heater shroud, P/N 23507-00 on PA-24, and P/N 23489-00 on PA-24 "250". Center the tailpipe in the shroud tailpipe opening.

(3) Reinstall the muffler exhaust stacks, tailpipe, and air ducts on airplane.

NOTE: PA-24 and PA-24 "250" mufflers have been manufactured incorporating two different styles of tailpipe reinforcement brackets. This AD requires modification of one style only - those with channel style reinforcement. See Sketch A of Piper Service Bulletin No. 210 for further identification. Both types of mufflers have been sold as service replacements. It will therefore be necessary to examine aircraft Serial Numbers 24-1 to 24-2587 inclusive, if the original muffler has been replaced, to determine if the modification is required. Aircraft Serial Numbers 24-2588 through 24-3284, were manufactured with the channel shaped reinforcement and will require modification except those already modified as indicated.

(Use Piper Service Letter No. 324B as a guide for inspections in addition to Service Bulletin No. 210.)

This directive effective December 5, 1962.