# Piper Service Bulletin 1337: No revision named - Rights: © Piper. Filed by the FAA in regulations.gov docket FAA-2020-0712; AD 2020-24-09 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [Piper Service Bulletin 1337](https://openairdocs.org/service-documents/piper/sb-1337.md) - Title as filed: SB1337 - Pages: 7 - PDF: https://openairdocs.org/files/sha256/11/e3/11e3b062869aa91371706e807a41f6a40f8c8061dae8461a6dcecf6af2c1d246 - Page: https://openairdocs.org/service-documents/piper/sb-1337/file/11e3b062869a ## Text Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 Date: February 15, 2019 (M) SERVICE BULLETIN NO. 1337 PIPER CONSIDERS COMPLIANCE MANDATORY Piper Aircraft, Inc. 2926 Piper Drive Vero Beach, FL, U.S.A. 32960 (OVER) ATA/JASC: 2460, 2497 SUBJECT: EMERGENCY POWER SUPPLY MODIFICATION MODELS AFFECTED: SERIAL NUMBERS AFFECTED: PA-34-220T Seneca V 3449459, 3449467 through 3449508 COMPLIANCE TIME: To coincide with the next regularly scheduled maintenance event, but not to exceed the next 100 hours time in service APPROVAL: The engineering aspects of this service document have been shown to comply with the applicable Federal Aviation Regulations and are FAA approved. PURPOSE: This service bulletin provides instructions for the modification of the emergency power supply assembly. SAFETY INTENT: The safety intent of this service bulletin is to prevent electrical arcing between a wire bundle and the rudder control cables, which, if not corrected, could cause failure of the rudder control system. CONFIGURATION DESCRIPTION: Incorporating this service bulletin results in a portion of the emergency power wiring being rerouted to improve clearance from the rudder control cables. 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 temporary removal of interior components, fairings and/or access panels may be required in order to accomplish the following instructions. 1. Disconnect electrical power from the affected systems: • Pull the breakers marked “Emer Batt Position 340” (on the circuit breaker panel) and “ESS Bus 1 & 2” (on the instrument panel). • Alternatively, disconnect both the primary and emergency batteries. The batteries are in the same area as the emergency power supply assembly (see Figure 1). ### Page 2 SERVICE BULLETIN NO. 1337 PAGE 2 of 7 2. RC – Identify the Emergency Power Supply (EPS) Assembly, Piper part number (P/N) 107279-002, mounted under the floor of the aft baggage compartment (located behind the last row of seats). See Figure 1. Remove the assembly, P/N 107279-002, from the aircraft. 3. RC – Inspect the rudder flight control cables and the EPS wiring for chafing and other damage. • To inspect the rudder control cables for damage, refer to Piper PA-34-220T Seneca IV/V Airplane Mainte - nance Manual, P/N 761-888, Sections 27-00-00 and 27-20-00. For replacement, if required, refer to Section 27-20-00. • If any damage to wiring is evident, repair or replace per FAA Advisory Circular (AC) 43.13-1B, Chapter 11. 4. RC – In order to prevent chafing of the relocated wire harness, install a Grommet, MS21266-1N, as follows: a. Prepare mounting surface by cleaning with isopropyl alcohol. b. Cut a section of MS21266-1N grommet to a length to fit the edge, identified in Figure 2, View C–C, of Bracket, P/N 107384-001. Bond the grommet in place using 3M Adhesive EC-1300L or 1300L (or equivalent). Alternatively, bond the grommet in place using epoxy resin. 5. RC – Install two (2) new Panduit ABMM-A Cable Tie Mounts (Piper P/N 279-044), or an equivalent, as follows: a. Prepare the mounting surface by cleaning it with isopropyl alcohol. b. Peel the backing paper off of each cable tie mount. Position the adhesive mount on the surface, in locations approximate to those shown in View D–D. Press the mounts firmly onto the surface. 6. RC – Remove the Cover, P/N 95213-002. Retain the cover and hardware for reuse. 7. RC – Remove the two (2) cable tie straps that hold the wire harness to the ABMM-A cable tie mounts. Discard the cable tie straps. 8. RC – Relocate the wiring harness as follows: a. Remove the Bridge Rectifier, P/N 584-465, from the Bracket, P/N 107384-001. NOTE: Do not remove the two wires that are soldered onto the bridge rectifier. It is not necessary to remove them to accomplish this modification. b. Reroute the wiring connected to the Terminal Board, MS27212-1-6, to the opposite side of Bracket, P/N 107384-001, as shown in View B–B and other figure illustrations. The terminal stack-up is shown in View E–E. c. Torque the terminal nuts to 22 in-lb. d. Rotate the rectifier 180 degrees and reinstall it, as shown in Detail K. 9. RC – Secure the wiring harness to the cable tie mounts, which were installed in Step 5, with two (2) cable tie straps MS3367-4-9, as shown in View D–D. Alternatively, use any MS3367 series cable tie straps that will fit through the slots of the cable tie mounts. 10. RC – Reinstall the Cover, P/N 95213-002, with the opening facing to the right (that is, rotated 180 degrees from its original configuration), to provide clearance for the new routing path for the wiring. 11. RC – Locate the clamp securing the power cable P10A4, shown in Figure 3. In order to prevent possible chafing of the relocated wiring harness, rearrange the mounting hardware with the screw heads on inboard side of the Zee Assembly, P/N 68632, as shown in View F–F . Accordingly, install the washer, nut and clamp on the outboard side. 12. RC – Reinstall the Emergency Power Supply Assembly, P/N 107279-002, into the aircraft. Confirm that there is a minimum of 1.50 inches of separation between all flight control cables and wires P38B12 and P38C12 (with the wires connected to the bridge rectifier D302). 13. Reconnect the electrical power that was disconnected in Step 1. 14. RC – Perform a functional test on any electrical systems that were disturbed during this modification. 15. RC – Make a logbook entry documenting compliance with this service bulletin. ### Page 3 SERVICE BULLETIN NO. 1337 PAGE 3 of 7 Figure 1 Emergency Power Supply Location SEE DETAIL J LOOKING DOWN AT THE FUSELAGE FWD FS 168.78 REF DETAIL J EMERGENCY POWER SUPPLY ASSEMBLY, MAIN AND EMERGENCY BATTERY EPS ASSEMBLY P/N 107279-002 A A B B C C MAIN BATTERY EMERGENCY BATTERY FF ### Page 4 SERVICE BULLETIN NO. 1337 PAGE 4 of 7 Figure 2, Sheet 1 of 3 Emergency Power Supply Assembly Modification F802 F801 F800 F803F804F805 F808 F807 F806 F809F810 K408 K409 P615 J356 PIR 107279 A 03 VIEW B−B AFTER MODIFICATION LOOKING UP, AS INSTALLED, AT EMERGENCY POWER SUPPLY ASSEMBLY SEE DETAIL L SEE DETAIL K WIRING HARNESS MOVED TO LEFT HAND SIDE (AS INSTALLED) BRIDGE RECTIFIER ROTATED 180 DEGREES BRACKET P/N 107384-001 D D PIR 107279 NEW 03 VIEW A−A BEFORE MODIFICATION LOOKING UP, AS INSTALLED, AT EMERGENCY POWER SUPPLY ASSEMBLY REMOVE COVER P/N 95213-002 (TWO SCREWS) REMOVE THE 2 CABLE TIES THAT ATTACH HARNESS TO CABLE TIE MOUNTS BRIDGE RECTIFIER P/N 584-465 FWD ### Page 5 SERVICE BULLETIN NO. 1337 PAGE 5 of 7 Figure 2, Sheet 2 of 3 Emergency Power Supply Assembly Modification DETAIL K LOOKING UP MODIFIED INSTALLATION OF BRIDGE RECTIFIER (D302) BRIDGE RECTIFIER P/N 584-465 BEVELED CORNER (REF) FWD VIEW C−C LOOKING FORWARD MODIFIED INSTALLATION OF EPS BRACKET UP GROMMET MS21266-1N P/N 189-625 GROMMET MS2166-1N (ALREADY INSTALLED) BRIDGE RECTIFIER WIRING (CONFIGURATION AFTER MODIFICATION) BRIDGE RECTIFIER (REF) (AFTER MODIFICATION) BRACKET P/N 107834-001 VIEW D−D MODIFIED INSTALLATION OF EPS ASSEMBLY FWD UP ATTACH HARNESS TO MOUNT: CABLE TIES MS3367-4-9 (OR EQUIVALENT) (2 REQ.) PANDUIT ABMM-A CABLE TIE MOUNT PIPER P/N 279-044 (OR EQUIVALENT) (2 REQ.) ### Page 6 SERVICE BULLETIN NO. 1337 PAGE 6 of 7 Figure 2, Sheet 3 of 3 Emergency Power Supply Assembly Modification (MS27212-1-6 TERMINAL BOARD) PIR 107279 A 03 DETAIL L EMERGENCY POWER SUPPLY MODIFIED WIRING TERMINATION (LOOKING UP) BRACKET P/N 107384-001 TERMINAL BOARD MS27212-1-6 SCREW MS51861-34 (2 REQ.) E E FWD VIEW E−E EMERGENCY POWER SUPPLY TERMINAL INSTALLATION STACK-UP DOWN COVER P/N 95213-002 TERMINAL STRIP BUS P/N 35207-004 COVER P/N 95213-000 NUT NAS679A06 WASHER NAS1149FN616P (6 PLACES) SCREW MS35206-217 WASHER NAS1149FN416P NUT MS21042-04 (2 PLACES) TERMINAL BOARD MS27212-1-6 WIRE WITH RING TERMINAL (6 PLACES) ### Page 7 SERVICE BULLETIN NO. 1337 PAGE 7 of 7 Figure 3 Battery Power Cable Installation Modification VIEW F−F AFTER MODIFICATION LOOKING INBOARD AT ZEE ASSEMBLY MAIN BATTERY CABLE CLAMPS REINSTALL THIS CLAMP HARDWARE WITH SCREW HEAD INBOARD, WASHER AND NUT OUTBOARD (REVERSE OF ORIGINAL) ZEE ASSEMBLY POWER CABLE P10A4 FWD UP MATERIAL REQUIRED: Per aircraft: • Two (2) each, Cable Tie Mounts, Panduit ABMM-A (Piper P/N 279-044), or equivalent • Two (2) each, Cable Tie Straps, MS3367-4-9 (Piper P/N 488-722), or other suitable MS3367 series straps • Sufficient length, Grommet MS21266-1N (Piper P/N 189-625) AVAILABILITY OF PARTS: Y our Piper Approved Service Center, or procure locally EFFECTIVITY DATE: This service bulletin is effective upon receipt. 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” --- 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, except the copies of manufacturers’ service documents, which belong to their rights holders.