REVISION TRANSMITTAL TO: Cessna Distributors, Multi-Engine Authorized Service Facilities, and CPC's SUBJECT: Multi-Engine Service Letter Revision 1: Hydraulic Power Pack Inspection REASON To add a coarse-threaded nut to the required replacement nuts. Miscellaneous changes as required. Please replace any copy of with the attached copy of Revision 1, which is printed in its entirety. NOTE: If you were able to comply with Original Issue, compliance with Revision 1 is not required. LOG OF REVISIONS Page No. Date Page No. Date 1 October 3, 2012 4 October 3, 2012 2 October 3, 2012 5 October 3, 2012 3 October 3, 2012 6 October 3, 2012 Original Issue - July 14, 2012 Revision 1 - October 3, 2012 Page 1 of 1 Cessna Aircraft Company, Cessna Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800, Fax 1-316-517-7271, Email: customercare@cessna.textron.com COPYRIGHT 2012
TITLE HYDRAULIC POWER - HYDRAULIC POWER PACK INSPECTION EFFECTIVITY MODEL T303 SERIAL NUMBERS T30300001 thru T30300315 REASON Cessna has received a report of possible electrical arcing at the positive terminal connection on the hydraulic power pack motor for the landing gear. DESCRIPTION This service letter provides instructions to do an inspection of the hydraulic power pack wiring for correct installation. COMPLIANCE MANDATORY. This service letter must be accomplished at the next scheduled 100 hour/12 month (annual) type inspection. NOTE: If you were able to comply with Original Issue, compliance with Revision 1 is not required. REFERENCES Applicable Cessna Airplane Service/Maintenance Manuals, Wiring Diagram Manuals, and Illustrated Parts Catalogs. Refer to www.cessnasupport.com. ACCOMPLISHMENT INSTRUCTIONS 1. Prepare the airplane for maintenance. A. Make sure that the airplane is electrically grounded. B. Make sure that all switches are in the OFF/NORM position. C. Disconnect electrical power from the airplane. (1) Disconnect the airplane battery. (2) Disconnect external electrical power. D. Attach maintenance warning tags to the battery and external power receptacle that have "DO NOT CONNECT ELECTRICAL POWER - MAINTENANCE IN PROGRESS" writtenonthem. 2. Get access to the hydraulic power pack for the landing gear. (Refer to the applicable service/maintenance manual.) 3. (Refer to Figure 1, Detail A and Detail B.) Do an inspection of the installation of the power lead and suppression diode connections to the hydraulic power pack as follows: A. Look at the positive terminal to see if there is evidence that arcing has occurred. (1) If you see no evidence that arcing has occurred, go to Step 3.B. Original Issue - July 14, 2012 Revision 1 - October 3, 2012 Page 1 of 6 Cessna Aircraft Company, Cessna Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800, Fax 1-316-517-7271, Email: customercare@cessna.textron.com This document contains technical data and is subject to U.S. export regulations. This information has been exported from the United States in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E991 COPYRIGHT 2012
(2) If you see evidence that arcing has occurred, repair or replace all damaged components. Then go to Step 3.B. (Refer to the applicable service/maintenance manual, wiring diagram manual, and illustrated parts catalog.) B. Look at the wiring for condition and installation as follows: (Refer to the applicable service/maintenance manual, wiring diagram manual, and illustrated parts catalog.) Look to see if the routing of the power wire and diode's negative lead are oriented up and away from the case in accordance with best practices, applicable service/maintenance manual, and applicable wiring diagram manual. Make sure that the power lead and diode's negative lead are secured between the two positive terminal nuts so that the bottom nut acts as a spacer and that under the bottom nut is an insulating washer. Make sure that the power lead and diode's negative lead ring terminals at the positive terminal are not bent toward the case of the power pack. (1) If the wiring is in serviceable condition and the routing of the power wiring and diode is done correctly,gotostep3.c. (2) If the wiring is not in serviceable condition and/or the routing of the power wiring and/or diode lead is not done correctly, do as follows: (Refer to the applicable service/maintenance manual, wiring diagram manual, and illustrated parts catalog.) NOTE: In some installations, the two case bolts may be safety wired. (a) (b) (c) (d) (e) (f) Repair/replace the wiring and/or do the routing of the wiring again as necessary until it is in accordance with best practices and the applicable service/maintenance manual and wiring diagram manual, as described in Step 3.B. Make sure that the attachment hardware for the 1270717-2 Diode Assembly is installed exactly as shown in Figure 1. Make sure that the 1270717-2 Diode Assembly is installed with the marking band (negative lead) on the diode facing toward the positive terminal. Use MS3367-1-9 Tie Straps as necessary to securely attach wires to make sure that the power lead and diode assembly wires do not touch the case of the power pack. If you must remove the attachment hardware for the 1270717-2 Diode Assembly, as you install it again make sure that the nut closest to the power pack is snug against the insulating washer. Tighten this nut with your hand and then, with a wrench on the nut, tighten the nut a quarter turn more. If you must torque a nut on the power pack, use a backup wrench on the nut adjacent to the insulators to make sure that no stress is put on the insulators and that none of the torque is transferred to the terminal posts. C. Look to see if an A-A59178-3 Nipple is in serviceable condition, installed over the wiring at the positive terminal, and securely attached in position as necessary with tie strap(s). Make sure that the nipple covers both the diode wire and the power terminal wire. (1) If an A-A59178-3 Nipple is in serviceable condition and is securely installed over the wiring at theterminal,gotostep4. (2) If a nipple is installed over the wiring at the terminal and the nipple is deteriorated or damaged, discard the nipple, trim the end of the new A-A59178-3 Nipple where the wires come out if necessary, install the new A-A59178-3 Nipple, and attach it securely in place with tie straps as necessary. Then go to Step 4. (3) If no A-A59178-3 Nipple is installed over the wiring at the terminal, trim the end of the new A-A59178-3 Nipple where the wires come out if necessary, install the new A-A59178-3 Nipple, and attach it securely in place with tie straps as necessary. Then go to Step 4. 4. Connect the airplane battery. Page 2 Revision 1 - October 3, 2012
5. Do a general inspection of the power pack installation for secure attachment, correct installation, and hydraulic leaks. 6. If you removed or replaced wiring or components, or corrected the routing of the wires for the power pack, do a functional test of the retractable landing gear operation. (Refer to the applicable Service/Maintenance Manual.) 7. Install components that you removed to get access to the hydraulic power pack. (Refer to the applicable service/maintenance manual.) 8. Remove the maintenance warning tags. 9. Make an entry in the airplane logbook that states compliance and method of compliance with this service letter. Revision 1 - October 3, 2012 Page 3
Figure 1. Hydraulic Power Pack Inspection (Sheet 1) Page 4 Revision 1 - October 3, 2012
Figure 1. Hydraulic Power Pack Inspection (Sheet 2) Revision 1 - October 3, 2012 Page 5
MATERIAL INFORMATION The parts below may be necessary and are available from Cessna Service Parts and Programs through an appropriate Cessna Authorized Service Facility. NEW P/N QUANTITY KEY WORD OLD P/N INSTRUCTIONS/ DISPOSITION A-A59178-3 1 Nipple Various Discard (If necessary) MS3367-1-9 As required Tie Strap Various MS35338-44 1 Lock Washer Various *MS35650-3252 2 Nut Various NAS1149F0416P 2 Flat Washer Various S1438-17 1 Insulating Washer Various 1270717-2 1 Diode Assembly Various The part below may be necessary and is commercially available. NEW P/N QUANTITY KEY WORD OLD P/N INSTRUCTIONS/ DISPOSITION *MS35690-405 2 Nut Various *Depending on the installation, you may need MS35650-3252 (fine-threaded) or MS35690-405 (coarse-threaded) Nuts. Page 6 Revision 1 - October 3, 2012
OWNER ADVISORY TITLE HYDRAULIC POWER - HYDRAULIC POWER PACK INSPECTION TO: Cessna T303 Owner REASON This owner advisory is to inform you that Revision 1 has been issued. Cessna has received a report of possible electrical arcing at the positive terminal connection on the hydraulic power pack motor for the landing gear. provides instructions to do an inspection of the hydraulic power pack wiring for correct installation. Revision 1 has been issued to, depending on the installation, add a coarse-threaded nut to the required replacement nuts. COMPLIANCE MANDATORY. This service letter must be accomplished at the next scheduled 100 hour/12 month (annual) type inspection. NOTE: If you were able to comply with Original Issue, compliance with Revision 1 is not required. LABOR HOURS Approximately 1.0 man-hour to accomplish this service letter WARRANTY Not Applicable Please contact a Cessna Multi Engine Authorized Service Facility for detailed information and arrange to have Cessna Service Letter Revision 1 accomplished on your airplane. NOTE: As a convenience, service documents are now available online to all our customers through a simple, free-of-charge registration process. If you would like to sign up, please visit the "Customer Access" link at www.cessnasupport.com to register. Original Issue - July 14, 2012 Revision 1 - October 3, 2012 Page 1 of 1 Cessna Aircraft Company, Cessna Customer Service, P.O. Box 7706, Wichita, KS 67277, U.S.A. 1-316-517-5800, Fax 1-316-517-7271, Email: customercare@cessna.textron.com This document contains technical data and is subject to U.S. export regulations. This information has been exported from the United States in accordance with export administration regulations. Diversion contrary to U.S. law is prohibited. ECCN: 9E991 COPYRIGHT 2012