# SAIB AIR-21-10: Wing, Attach Fittings (JASC 5740) - Type: Special airworthiness information bulletin (advisory, not mandatory) - Status: Current - Revision: 0 - Issued: June 29, 2021 - Products: Piper Aircraft^ PA-28-140, PA-28-150, PA-28-151, PA-28-160, PA-28-161, PA-28-180, PA-28-181, PA-28-201T, PA-28-235, PA-28-236, PA-28R-180, PA-28R-200 and 24 more - Product type: Aircraft, Small Airplane - PDF: https://openairdocs.org/files/sha256/50/cc/50ccdd702c77aca25367d44083cd112ced1611c217c4400a755e341804cf60de - FAA DRS: https://drs.faa.gov/browse/excelExternalWindow/176E71313AC51FCC86258703007D647D.0001 - DRS record last changed: June 29, 2021 - Page: https://openairdocs.org/saib/AIR-21-10 ## Text Some pages are OCR from the scanned FAA bulletin. OCR can misread letters and numbers. FAA Aviation Safety **SPECIAL** **AIRWORTHINESS** **INFORMATION BULLETIN** SUBJ: Wing, Attach Fittings (JASC 5740) This is information only. Recommendations aren’t mandatory. SAIB: AIR-21-10 Date: June 29, 2021 Introduction This Special Airworthiness Information Bulletin is to advise owners and operators of Piper Aircraft, Inc. PA-28, PA-32, PA-34, and PA-44 (see list of specific models in “Background” section) airplanes of the potential for corrosion of the forward spar to fuselage attach fittings, in an area that may not be easily accessible for inspection We have determined that no regulatory action is necessary at this time because the airworthiness concern is not an unsafe condition that would warrant an FAA AD under 14 CFR part 39. Background Piper Aircraft, Inc. issued Service Bulletins (SB) 789A, 977, and 1244B to inspect for corrosion on the aft wing spar to fuselage attach fittings. At the time the service bulletins were written, the corrosion was attributed to water intrusion, and forward attach fittings were not considered to be subject to the water intrusion issues affecting the aft attach fittings. Therefore, inspections of the forward attach fittings were not included in those service bulletins. Since then, the FAA became aware of several cases of severe corrosion on the forward attach fittings from operators in Florida. While no evidence exists of water intrusion at the forward locations, the potential exists for galvanic corrosion between the dissimilar metals of the steel fittings and aluminum spar. Due to the restricted accessibility of the forward attach fittings in some airplanes, owners may be neglecting to have this area inspected. See Figures 1 through 3 depicting corrosion location and characteristics. The specific Piper Aircraft, Inc. models affected are: PA-28-140, PA-28-150, PA-28-151, PA-28- 160, PA-28-161, PA-28-180, PA-28-181, PA-28-201T, PA-28-235, PA-28-236, PA-28R-180, PA- 28R-200, PA-28R-201, PA-28R-201T, PA-28RT-201, PA-28RT-201T, PA-28S-160, PA-28S-180, PA-32-260, PA-32-300, PA-32-301, PA-32-301FT, PA-32-301T, PA-32-301XTC, PA-32R-300; PA-32R-301 (HP), PA-32R-301 (SP), PA-32R-301T, PA-32RT-300, PA-32RT-300T, PA-32S-300, PA-34-200, PA-34-200T, PA-34-220T, PA-44-180, and PA-44-180T. Recommendations The FAA is recommending that owners take special care to ensure that the forward wing attach fittings are visually inspected during annual or 100-hour inspections in accordance with the applicable Piper Aircraft, Inc. Maintenance Manual. Some operators have had inspection panels or borescope inspection holes installed to facilitate inspection (contact Piper Aircraft, Inc. for acceptable options). “Powdery” rivets in the attach fitting are indicative of corrosion between the steel and aluminum surfaces. Particularly susceptible are those airplanes operating in coastal or otherwise corrosive environments. For Further Information Contact Dan McCully, Aviation Safety Engineer, Atlanta ACO Branch, FAA, 1701 Columbia Avenue, College Park, GA 30337; phone: (404) 474-5548; fax: (404) 474-5605; email: william.mccully@faa.gov. 35630 38643 101 SKETCH A SECTION A-A BOLT NAS1104-17 WASHER AN960-416L (UNDER HEAD) WASHER AN960-416 (UNDER NUT) NUT MS21045-4 SEE NOTE **0.12 MIN.** **0.35 MAX.** **TORQUE NUT 50-60 IN-LBS NOTE MINIMUM OFHEN UNDER NUT.** AN960-416 OR AN960-416L AS **REQUIRED TO LEAVE A MAXIMUM OF 1 1/2** **THREADS OR MINIMUM** **OF BOLT CHAMFER** EXPOSED Figure 1. Forward Attach Fitting Figure 2. PA-28 Corroded Forward Attach Fitting and Spar Section (removed) **FORWARD FITTING INSIDE WING** **LEADING EDGE SHOWING** CORRODED RIVET HEADS Figure 3. Wing Interior Showing Galvanic Corrosion ## Registered aircraft it may concern (OpenAirDocs) Registry models matched by make and model, the same way as ADs, most registered aircraft first. - [Piper PA-28-140](https://openairdocs.org/model/piper-pa-28-140): 4,258 registered aircraft (airframe model) - [Piper PA-28-181](https://openairdocs.org/model/piper-pa-28-181): 3,549 registered aircraft (airframe model) - [Piper PA-28-180](https://openairdocs.org/model/piper-pa-28-180): 3,504 registered aircraft (airframe model) - [Piper PA-28-161](https://openairdocs.org/model/piper-pa-28-161): 1,526 registered aircraft (airframe model) - [Piper PA-28R-200](https://openairdocs.org/model/piper-pa-28r-200): 1,223 registered aircraft (airframe model) - [Piper PA-32-300](https://openairdocs.org/model/piper-pa-32-300): 992 registered aircraft (airframe model) - [Piper PA-28-151](https://openairdocs.org/model/piper-pa-28-151): 961 registered aircraft (airframe model) - [Piper PA-28-235](https://openairdocs.org/model/piper-pa-28-235): 859 registered aircraft (airframe model) - [Piper PA-32-260](https://openairdocs.org/model/piper-pa-32-260): 650 registered aircraft (airframe model) - [Piper PA-34-200T](https://openairdocs.org/model/piper-pa-34-200t): 563 registered aircraft (airframe model) - [Piper PA-44-180](https://openairdocs.org/model/piper-pa-44-180): 558 registered aircraft (airframe model) - [Piper PA-28R-180](https://openairdocs.org/model/piper-pa-28r-180): 536 registered aircraft (airframe model) - [Piper PA-32R-301T](https://openairdocs.org/model/piper-pa-32r-301t): 536 registered aircraft (airframe model) - [Piper PA-32R-300](https://openairdocs.org/model/piper-pa-32r-300): 510 registered aircraft (airframe model) - [Piper PA-28-236](https://openairdocs.org/model/piper-pa-28-236): 480 registered aircraft (airframe model) - [Piper PA-32R-301](https://openairdocs.org/model/piper-pa-32r-301): 456 registered aircraft (airframe model) - [Piper PA-28R-201T](https://openairdocs.org/model/piper-pa-28r-201t): 368 registered aircraft (airframe model) - [Piper PA-28R-201](https://openairdocs.org/model/piper-pa-28r-201): 352 registered aircraft (airframe model) - [Piper PA-28RT-201T](https://openairdocs.org/model/piper-pa-28rt-201t): 255 registered aircraft (airframe model) - [Piper PA-28-160](https://openairdocs.org/model/piper-pa-28-160): 253 registered aircraft (airframe model) - [Piper PA-34-220T](https://openairdocs.org/model/piper-pa-34-220t): 248 registered aircraft (airframe model) - [Piper PA-32RT-300T](https://openairdocs.org/model/piper-pa-32rt-300t): 204 registered aircraft (airframe model) - [Piper PA-32RT-300](https://openairdocs.org/model/piper-pa-32rt-300): 200 registered aircraft (airframe model) - [Piper PA-28RT-201](https://openairdocs.org/model/piper-pa-28rt-201): 178 registered aircraft (airframe model) - [Piper PA-34-200](https://openairdocs.org/model/piper-pa-34-200): 172 registered aircraft (airframe model) - [Piper PA-32-301](https://openairdocs.org/model/piper-pa-32-301): 167 registered aircraft (airframe model) - [Piper PA-28-150](https://openairdocs.org/model/piper-pa-28-150): 123 registered aircraft (airframe model) - [Piper PA-32-301T](https://openairdocs.org/model/piper-pa-32-301t): 81 registered aircraft (airframe model) - [Piper PA-28-201T](https://openairdocs.org/model/piper-pa-28-201t): 62 registered aircraft (airframe model) - [Piper PA32-301FT](https://openairdocs.org/model/piper-pa32-301ft): 39 registered aircraft (airframe model) - [Piper PA-44-180T](https://openairdocs.org/model/piper-pa-44-180t): 38 registered aircraft (airframe model) - [Piper PA32-301XTC](https://openairdocs.org/model/piper-pa32-301xtc): 36 registered aircraft (airframe model) - [New Piper PA-32R-301T](https://openairdocs.org/model/new-piper-pa-32r-301t): 19 registered aircraft (airframe model) - [New Piper PA-28-181](https://openairdocs.org/model/new-piper-pa-28-181): 16 registered aircraft (airframe model) - [New Piper PA-28-161](https://openairdocs.org/model/new-piper-pa-28-161): 15 registered aircraft (airframe model) - [New Piper PA-34-220T](https://openairdocs.org/model/new-piper-pa-34-220t): 8 registered aircraft (airframe model) - [New Piper PA-32-301XTC](https://openairdocs.org/model/new-piper-pa-32-301xtc): 7 registered aircraft (airframe model) - [New Piper PA-32R-301](https://openairdocs.org/model/new-piper-pa-32r-301): 6 registered aircraft (airframe model) - [New Piper PA-44-180](https://openairdocs.org/model/new-piper-pa-44-180): 4 registered aircraft (airframe model) - [New Piper PA32-301FT](https://openairdocs.org/model/new-piper-pa32-301ft): 4 registered aircraft (airframe model) - [Piper PA-32S-300](https://openairdocs.org/model/piper-pa-32s-300): 3 registered aircraft (airframe model) - [Piper PA-28S-180](https://openairdocs.org/model/piper-pa-28s-180): 1 registered aircraft (airframe model) - [Piper/Valdes-Ervin PA-28-235](https://openairdocs.org/model/piper-valdes-ervin-pa-28-235): 1 registered aircraft (airframe model) - [New Piper PA-28R-201](https://openairdocs.org/model/new-piper-pa-28r-201): 0 registered aircraft (airframe model) - [New Piper PA-44-180T](https://openairdocs.org/model/new-piper-pa-44-180t): 0 registered aircraft (airframe model) - [Piper / Beaumont PA-28-140](https://openairdocs.org/model/piper-beaumont-pa-28-140): 0 registered aircraft (airframe model) - [Piper PA-28S-160](https://openairdocs.org/model/piper-pa-28s-160): 0 registered aircraft (airframe model) - [Piper/Anderson PA 28-180](https://openairdocs.org/model/piper-anderson-pa-28-180): 0 registered aircraft (airframe model) - [Piper/Flores Richard PA 28-181](https://openairdocs.org/model/piper-flores-richard-pa-28-181): 0 registered aircraft (airframe model) - [Piper/Miller PA-28-140](https://openairdocs.org/model/piper-miller-pa-28-140): 0 registered aircraft (airframe model) --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.