SERVICE BULLETIN NO. 1161D

thereby reducing the shear buckling capability of the spar web and torsional strength of the wing. This service bulletin provides a schedule for inspection to detect the presence of cracks, and announces the availability of service kits, which include the parts and instructions to repair the aft rib assembly, if a crack is discovered. It also announces the availability of replacement rib assemblies that, where installed, will relieve the recurring inspections described in Part I of this service bulletin Group B: The detailed inspection requirements applicable to airplanes in Group A do not apply to airplanes in Group B. However, should damage occur to airplanes in Group B, due to a hard landing or some other cause, this service bulletin announces the availability of a repair kit, provided that the damage is within the limits specified in the Instructions section of this service bulletin. INSTRUCTIONS: WARNING: FLIGHT WITH KNOWN CRACKS IN THE AIRCRAFT STRUCTURE IS NOT ALLOWED. AN AIRPLANE WITH A CRACK IN STRUCTURE MAY NO LONGER MEET ITS TYPE DESIGN AND MAY NO LONGER POSSESS ITS TYPE DESIGN STRENGTH. ANY CRACKS DISCOVERED IN THE AIRCRAFT STRUCTURE MUST BE REPAIRED PRIOR TO THE NEXT FLIGHT. Part I. Detailed Inspection For the initial 50 hour inspection, and at each 500 hour interval thereafter: NOTE: Perform the following instructions per the appropriate service/maintenance manual, when required. 1. Place the aircraft on jacks, and perform the following disassembly and inspection on the LH and RH wings. 2. Remove the main landing gear side brace by removing the five bolts that fasten it to the wing structure. Retain the hardware for reassembly. 3. Inspect the aft rib assembly (LH wing and RH wing) for evidence of cracks in the bend radius of the flange common to the main spar web (as shown in Figure 1), using dye penetrant inspection techniques. Use guidance from FAA Advisory Circular AC43.13-1B. • If a crack is detected, identify the path of propagation. Determine if trimming will remove all the material affected by the crack, as illustrated in Figure 1. • If so, then install the appropriate kit (see Material Required section of this service bulletin). Kit installation will eliminate the recurring inspection requirements mandated by Part I of this service bulletin. • If not, then replacement of the aft rib assembly is mandated. • If a replacement Rib Assembly – Aft Wing – WS 49.25, P/N 78475-000 through 78475-009, is installed, this does not relieve the recurring inspection requirements of this service bulletin. However, the recurring inspections as described in Part I are relieved if the applicable kit P/N 767-397 or 767-398 is also installed, and if the kit instructions are marked drawing number 88373, revision J (or later). • If a replacement Rib Assembly – Aft Wing – WS 49.25, P/N 78475-010 or higher, as defined in Table 1, is installed, this relieves the recurring inspection requirements described in Part I of this service bulletin.(Installation of either kit P/N 767-397 or 767-398 is not required, in this case.) • If a crack is not detected, then the recurring inspection requirements mandated by Part I of this service bulle- tin can be eliminated by installing the appropriate kit (see the Material Required section of this service bulletin). NOTE: Prior to installing a kit, verify that the instructions are marked Dwg No. 88373, revision J (or later). SERVICE BULLETIN NO. 1161D PAGE 4 of 6 4. Reassemble the main landing gear side brace, using existing hardware, after initial inspection and after 500 hour inspections or when disassembly was required. 5. Verify proper functioning of the landing gear. 6. Remove the airplane from jacks. 7. Make a logbook entry documenting compliance with Part I of this service bulletin, noting the accomplishment of the recurring inspection, or the structural modification of the LH and/or RH wing per kit instructions, as applicable. Part II. Standard Inspection 1. As part of the normal 100 hour recurring maintenance requirements: Inspect the forward and aft rib assemblies (LH and RH) for evidence of cracks at the location shown in Figure 1, except the inspection shall be limited to a visual examination of observable portions of the flange bend radii. Removal of the main landing gear side brace is not required at the 100 hour inspection interval. If a crack is detected in the aft rib, proceed to Part I, Detailed Inspection. If a crack is detected in the forward rib, repair or replacement of the forward rib assembly is mandated. Piper does not offer a standard for the forward rib assembly. NOTE: Prior to visual inspection, wipe surfaces clean using a soft cloth dampened with isopropyl alcohol, mineral spirits, naphtha, or other suitable cleaning agent. NOTE: This visual inspection shall be accomplished using a 10X magnifier, a mirror and a suitable light source or other equipment capable of providing equal or better resolution. 2. Make a logbook entry documenting compliance with Part II of this service bulletin. TABLE 1 REPLACEMENT RIB ASSEMBLY IF THE ORIGINAL PART NUMBER IS: THEN THE SERVICE PART NUMBER IS: 78475-000 78475-014 78475-001 78475-015 78475-002 78475-016 78475-003 78475-017 78475-004 78475-018 78475-005 78475-019 78475-006 78475-012 78475-007 78475-013 78475-008 78475-010 78475-009 78475-011 NOTE: Refer to the appropriate Piper Airplane Parts Catalog to determine the applicable original part number. SERVICE BULLETIN NO. 1161D PAGE 5 of 6 Figure 1 Determine if trimming will remove all material affected by cracks or damage in the aft rib assembly FWD UP MAIN AREA TO INSPECT FOR CRACKS OF THE FLANGE BEND RADIUS (See Note) DETERMINE THAT TRIMMING THE RIB BACK TO THIS LINE WILL REMOVE ALL THE MATERIAL AFFECTED BY THE CRACK. MAIN SPAR NOTE: App licable to the initial 50 hour inspection and 500 hour recurring inspection. Not applicable to the recurring 100 hour inspection. LOOKING OUTBOARD AT LEFT WING, WS 49.25 (RIGHT WING OPPOSITE) VISUALLY INSPECT FORWARD RIB ASSEMBLY FLANGE AND ASSOCIATED BEND RADIUS FOR CRACKS. FORWARD RIB ASSEMBLY AFT RIB ASSEMBLY SERVICE BULLETIN NO. 1161D PAGE 6 of 6 MATERIAL REQUIRED: One (1) each, [Part Name], Piper P/N [xxxxxx], per aircraft MATS. REQUIRES, MULTI.: Per aircraft: • One (1) each, [Part Name], Piper P/N [xxxxxx] • Three (3) each, [Part Name], Piper P/N [xxxxxx] AVAILABILITY OF PARTS: Your Piper Approved Service Center Find your local service center at https://www.piper.com/ EFFECTIVITY DATE: This service bulletin is effective on February 19, 2024. SUMMARY: REMOVE: first para below used only when offering warranty and, rarely, modified if Warranty wants to Applicable factory participation is limited to new aircraft in warranty at the time of compliance. Factory participation will remain in effect for a period of time not to exceed 180 days from the effectivity date of this service bulletin. Please contact your Piper Approved Service Center to make arrangements for compliance with this service bulletin in accordance with the compliance time indicated. NOTE: Please notify the factory of any address/ownership corrections. Changes should include aircraft model, serial number, and current owner’s name and address. Corrections and/or changes should be directed to: PIPER AIRCRAFT, INC. Attn: Customer Service 2926 Piper Drive Vero Beach, FL 32960 or: CustomerService@piper.com Please include in subject line: “Aircraft ownership update” MATERIAL REQUIRED: Per aircraft, on condition (refer to Part I, Step 3): • Up to two (2) each, Rib Assembly – Aft Wing – WS 49.25, P/N 78475-010 or higher per Table 1. • Up to one (1) each: • Kit P/N 767-397, Kit – Rib Repair, LH • Kit P/N 767-398, Kit – Rib Repair, RH AVAILABILITY OF PARTS: Your Piper Approved Service Center Find your local service center at https://www.piper.com/ EFFECTIVITY DATE: This service bulletin is effective on February 19, 2024. SUMMARY: Applicable factory participation is limited to new aircraft in warranty at the time of compliance. Factory participation will remain in effect for a period of time not to exceed 180 days from the date of this service bulletin. Please contact your Piper Approved Service Center to make arrangements for compliance with this service bulletin in accordance with the compliance time indicated. NOTE: Please notify the factory of any address/ownership corrections. Changes should include aircraft model, serial number, and current owner’s name and address. Corrections and/or changes should be directed to: PIPER AIRCRAFT, INC. Att’n: Customer Service 2926 Piper Drive Vero Beach, FL 32960 or: CustomerService@piper.com Please include in subject line: “Aircraft ownership update”