# SERVICE **BULLETIN**

Date: August 4, 2015 (M) 

## NO. 

# 1257A

**PIPER CONSIDERS COMPLIANCE MANDATORY**  **Piper Aircraft, Inc.** 2926 Piper Drive Vero Beach, FL, U.S.A. 32960

Service Bulletin (SB) 1257A supersedes SB 1257 in its entirety. Aircraft that have previously complied with SB 1257 are in compliance with SB 1257A until the next recurring scheduled maintenance event, as defined in this service bulletin’s COMPLIANCE TIME.

**S ub**  **j ect**  : **F uel**  **H ose**  **INSPECTION**

**R eason**  **for R**  **evision** : SB 1257A clarifies the various power plants in the affected airplanes.

**M odels**  **A ffected**  : **S erial**  **N umbers**  **A ffected**  : PA-31-350 Navajo Chieftain with (L)TIO-540-J2BD engines 31-5001 thru 31-5004; 31-7305005 thru 31-7405497; 31-7552001 thru 31-8452021 PA-31-350 T1020 with (L)TIO-540-J2B engines 31-8253001 thru 31-8553002

**COMPLIANCE TIME** : Initial compliance to coincide with the next regularly scheduled maintenance event, but not to exceed the next 25 hours time in service. Thereafter, recurring inspections are to be accomplished at intervals not to exceed 100 hours time in service. Additionally, compliance is to be accomplished whenever an engine fuel line or turbocharger support assembly is serviced, removed or replaced.
**APPROVAL** : The engineering aspects of this service document have been shown to comply with the applicable Federal Aviation Regulations and are FAA approved.
**PURPOSE** : Some of the affected aircraft may have inadequate clearance between the fuel inlet or exit hose assemblies of engine mounted fuel pumps and Lycoming supplied turbocharger support assemblies . This condition may cause a fitting of the fuel inlet or exit hose to crack over time and leak fuel. This service bulletin defines a minimum clearance requirement between the fuel inlet and exit hose assemblies and turbocharger support assemblies described above. This service bulletin requires mandatory on-condition replacement of the fuel hose assembly as well as repair or replacement of the turbocharger support assembly. For some of the affected aircraft, this service bulletin also provides instructions for identifying conforming fuel hoses.

ATA: 7310 (OVER) 

### 1**SERVICE BULLETIN NO. 1257A PAGE 2 of 5** 

**S afety**  **I ntent**  : The safety intent of this service bulletin is to minimize the likelihood of fuel hoses chafing against adjacent structure, which, if not corrected, could result in a fuel leak, with the potential for fire in the engine compartment.
**C onfiguration**  **D escription**  : Incorporating this service bulletin changes the orientation of a fuel fitting to ensure that fuel hoses in the engine compartment have adequate clearance from adjacent structure to prevent chafing.
**INSTRUCTIONS** : NOTE : Some steps in these instructions are identified as “required for compliance” (RC). If this service bulletin is mandated by an airworthiness directive (AD), the steps identified as RC must be done to comply with the AD. Steps not identified as RC are recommended and may be deviated from, done as a part of other actions, or done with accepted methods different from those given in this service bulletin, if the RC steps can be done and the airplane can be put back in a serviceable condition. NOTE : The instructions that follow apply to both left and right engines. Depending upon the specific aircraft model, the engines will be (L)TIO-540-J2BD or (L)TIO-540-J2B. NOTE : When installing/rerouting fuel hoses, refer to the appropriate Piper maintenance manual, as well as FAA Advisory Circular AC 43.13-1B (Acceptable Methods, Techniques, and Practices – Aircraft Inspection and Repair), Chapters 8 and 9, for further guidance. N ote : Some of the affected serial numbered airplanes will have an engine driven fuel pump and inlet fuel hose configuration which is different from what is shown in this service bulletin. For those airplanes, the inlet fuel pump hoses may be routed differently from what is shown. For these installations, the exit fuel hose and inlet fuel hose should be checked for a 3/16 inch minimum clearance from all adjacent structures. 1. RC – Remove upper and/or lower engine cowls as required to perform the instructions that follow. Refer to the appropriate maintenance manual for specific instructions. 2. RC – Identify the part number (P/N) of each fuel inlet hose assembly of each engine mounted fuel pump. If a fuel inlet hose assembly is not identified as Piper P/N 39995-034, then replace it with a serviceable Piper P/N 39995-034 (refer to Figure 1). NOTE : A conforming 39995-034 fuel hose assembly will be 30 inches long (as measured from sealing surface to sealing surface; approximately the distance between the centers of the locking nuts at each end of the hose). The fitting common to the engine mounted fuel pump will be a 3/4-16 NF3 thread, 45 degrees. The fitting at the opposite end will be a 3/4-16 NF3 thread, straight. 3. RC – Locate the area in each engine compartment where inlet and exit fuel hose assemblies are closest to the turbocharger support assembly, Lycoming P/N LW-18302. 4. RC – Measure the clearance between the inlet and exit fuel hose assemblies where closest to the turbocharger support assembly. If necessary, adjust routing of fuel hose assembly to achieve a minimum clearance of 3/16 inches. NOTE : For the inlet fuel hose assembly of TIO-540-J2B engine, a slight rotation of the 90° elbow fuel pump fitting towards the vertical position may assist in achieving the required clearance (refer to Figure 2). Since Lycoming installs this fitting into the fuel pump at the factory using sealant, any such adjustment will require complete removal of the fitting, cleaning of the threads common to the fitting and the fuel pump with methyl ethyl ketone (MEK) or acetone, and reinstallation of the fitting into the fuel pump using fresh Loctite ® 545TM Thread Sealant. Removal of the fuel pump from the engine may be required to accomplish this procedure.**SERVICE BULLETIN NO. 1257A PAGE 3 of 5** 

**Figure 1** Fuel Hose Assembly Proximity to Turbocharger Support ENGINE DRIVEN FUEL PUMP 90 ° ELBOW FUEL PUMP FITTING
TURBOCHARGER SUPPORT ASSEMBLY, LYCOMING P/N LW-18302

3/16” CLEARANCE INSPECTION AREA **3/16 IN. MIN.**
FUEL HOSE ASSEMBLY, PIPER P/N 39995-034

VIEW LOOKING FO R W ARD AND UP Representative Image - Fuel Inlet Fitting and Hose Assembly of a TIO-540-J2B Engine 5. RC – Inspect the fuel hose assemblies and associated fittings for evidence of leaks, cracks, chafing or damage. Replace on condition. 6. RC – Inspect the turbocharger support assembly for evidence of chafing or damage. Repair or replace on condition. 7. RC – If any fuel line component was adjusted, serviced or replaced, perform an engine run-up on the ground and check for leaks. 8. Reinstall engine cowls per maintenance manual instructions. 9. Make a logbook entry documenting compliance with this service bulletin.**SERVICE BULLETIN NO. 1257A PAGE 4 of 5** 

**Figure 2** Fuel Inlet Fitting Positioning BEFORE ADJUSTMENT TO IMPROVE CLEARANCE

Typical – Fuel Inlet Fitting of a TIO-540-J2B Engine ENGINE DRIVEN FUEL PUMP 90° ELBOW FUEL PUMP FITTING **N OT VERTICAL** 

UP

FWD

FUEL HOSE ASSEMBLY, PIPER P/N 39995-034

TURBOCHARGER SUPPORT ASSEMBLY

AFTER ADJUSTMENT TO IMPROVE CLEARANCE Typical – Fuel Inlet Fitting of a TIO-540-J2B Engine 90° ELBOW FUEL PUMP FITTING

TURBOCHARGER SUPPORT ASSEMBLY **vertical**

FUEL HOSE ASSEMBLY, PIPER P/N 39995-034 UP

FWD ENGINE DRIVEN FUEL PUMP**SERVICE BULLETIN NO. 1257A PAGE 5 of 5** 

**MATERIAL REQUIRED** : One (1) each (per engine), Fuel Hose Assembly, Piper P/N 39995-034, on condition One (1) each (per engine), Turbocharger Support Assembly, Lycoming P/N LW-18302, on condition
**AVAILABILITY OF PARTS** : Piper P/N 39995-034: Your Factory Authorized Piper Service Facility Lycoming P/N LW-18302: Your Lycoming Authorized Distributor

**E ffectivity**  **date** : This service bulletin is effective upon receipt.
**S ummary**  : Please contact your Factory Authorized Piper Service Facility to make arrangements for compliance with this service bulletin in accordance with the compliance time indicated.
**N ote**  : 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