Airworthiness Directive · Amendment 39-17457 · Engine exhaust
Piper Aircraft, Inc. Airplanes
This AD applies to turbocharged Piper Aircraft, Inc. Models PA-31, PA-31-325, and PA-31-350 airplanes, all serial numbers, certificated in any category.
We are superseding an existing airworthiness directive (AD) for all Piper Aircraft, Inc. Models PA-31, PA-31-325, and PA-31-350 airplanes. That AD currently requires a detailed repetitive inspection of the exhaust system downstream of the turbochargers and repair or replacement of parts as necessary. This new AD requires visual repetitive inspections, expanding the inspection scope to include the entirety of each airplane exhaust system. This AD was prompted by reports of exhaust system failures upstream of aircraft turbochargers and between recurring detailed inspections. We are issuing this AD to correct the unsafe condition on these products.
(1) Within the next 60 hours time-in-service (TIS) after July 17, 2013 (the effective date of this AD) or within the next 6 months after July 17, 2013 (the effective date of this AD), whichever occurs first, and repetitively thereafter at intervals not to exceed 60 hours TIS or 6 months, whichever occurs first, perform the inspections listed in table 1 of paragraph (g) of this AD upon the parts listed in the same table.
Note 1 to paragraph (g)(1) of this AD: Inspection procedure references can be found in Section 2, Visual Inspection, Chapter 5, Nondestructive Inspection (NDI), FAA Advisory Circular 43.13-1 B, Change 1, dated September 27, 2001, Acceptable Methods, Techniques, And Practices—Aircraft Inspection and Repair (http://www.airweb.faa.gov/Regulatory_and_Guidance_Library/rgAdvisoryCircular.nsf/0/99C827DB9BAAC81B86256B4500596C4E?OpenDocument&Highlight=ac43.13-1b).
(2) Aircraft equipped with Supplemental Type Certificate (STC) SA240CH heat exchanger will not have all of the parts referenced in table 1 of paragraph (g). (Information on STC SA240CH may be found at http://rgl.faa.gov/Regulatory_and_Guidance_Library/rgstc.nsf/0/30C512E870BE421D86257297005B6822?OpenDocument&Highlight=sa240ch.) The heat exchanger replaces some of those parts; therefore, this AD requires the visual inspection on only the remaining parts listed in table 1 of paragraph (g) of this AD after installation of STC SA240CH. Airplanes modified in accordance with STC SA240CH will not require an Alternative Method of Compliance if the corrective actions in this AD are complied with.
| Product/part nomenclature | Make | Model/part number | Inspect with light and mirror or other method capable of achieving an equivalent visual resolution: | ||
| Airplane | Piper | PA-31 | PA-31-325 | PA-31-350 | |
| Engine | Lycoming | TIO-540-A1A, -A1B, -A2A, -A2B and -A2C (standard cylinder flange; aka, narrow deck) | TIO-540-A2C (wide cylinder flange; aka, wide deck) and -F2BD, and LTIO-540-F2BD | TIO-540-J2B and -J2BD and LTIO-540-J2B and -J2BD | |
| Pipe, exhaust, right intermediate | Lycoming | LW-15850 | LW-15850 | LW-15849 | bulges, cracks and exhaust leak stains. |
| Pipe, exhaust, right rear, intermediate | Lycoming | LW-16792 | LW-16792 | LW-16621 | bulges, cracks and exhaust leak stains. |
| Pipe, exhaust, right rear | Lycoming | LW-16793 | LW-16793 | LW-16620 | bulges, cracks and exhaust leak stains. |
| Pipe, exhaust, left, intermediate | Lycoming | LW-15849 | LW-15849 | LW-15849 | bulges, cracks and exhaust leak stains. |
| Pipe, exhaust, left rear, intermediate | Lycoming | LW-16789 | LW-16789 | LW-16696 | bulges, cracks and exhaust leak stains. |
| Pipe, exhaust, left rear | Lycoming | LW-16790 | LW-16790 | LW-16697 | bulges, cracks and exhaust leak stains. |
| Tail pipe assembly, bottom | Piper | 40310-09 | 40310-09 | 40310-09 | bulges, cracks and exhaust leak stains. |
| Tail pipe assembly, top | Piper | 40310-08 or 40310-10 | 40310-08 or 40310-10 | 40319-10 | bulges, cracks and exhaust leak stains. |
| v-band coupling | Lycoming | LW-12093-5 | LW-12093-5 | LW12093-5 | cracks and exhaust leak stains. |
| v-band coupling | Piper | 555-511 or 557-584 | 555-511 or 557-584 | 555-366 or 557-369 | cracks and exhaust leak stains. |
(1) If any damage is found as a result of the inspections required in paragraph (g) of this AD, before further flight, do the following corrective actions:
(i) Replace v-band couplings exhibiting cracks and/or exhaust leak stains with airworthy and replacement v-band couplings following the applicable instructions contained in Piper Aircraft Corporation Service Bulletin No. 644E, dated May 9, 2012, and/or Lycoming Service Instruction No. 1238B, dated January 6, 2010.
(ii) Replace exhaust system parts exhibiting bulges, cracks and/or exhaust leak stains with airworthy parts in accordance with Lycoming Service Information 1320, dated March 7, 1975, and Lycoming Service Information 1391, dated October 5, 1979, as applicable.
Note 2 to paragraph (h) of this AD: During installation, we recommend not opening the v-band coupling more than the MINIMUM diameter necessary to clear coupled flanges. It is recommended to replace any locknuts and/or mating couplings with airworthy parts when locknuts do not exhibit a prevailing torque when installed.
The aircraft, engines and makers this AD names, by the model designations in its text. A model listed here may still be outside the AD's serial ranges.
