### Commercial **Airplanes** 

# 737 Service Bulletin
**Number: 737-53-1312** Original Issue: October 21, 2011 Revision 1: March 14, 2012 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Chem-mill Steps in Crown Skins at Specified Locations - Inspection and Modification Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws.9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2011 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 21, 2011 737-53-1312 Revision 1: March 14, 2012 1 of 4 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 21, 2011 737-53-1312 Revision 1: March 14, 2012 2 of 4 **BOEING SERVICE BULLETIN 737-53-1312**

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### Commercial **Airplanes** 

# 737 Service Bulletin

**Short Form Revision Number: 737-53-1312**  Original Issue: October 21, 2011 Revision 1: March 14, 2012 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Chem-mill Steps in Crown Skins at Specified Locations - Inspection and Modification Revision 1 is sent to change information. Only the changed information is described below. The Original Issue and Revision 1 are necessary to do the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** No more work is necessary on the airplane(s) changed in accordance with the original issue of this service bulletin. **REASON FOR REVISION** This revision is sent to revise compliance times for airplanes which have incorporated Boeing Business Jet (BBJ) Lower Cabin Altitude Supplemental Type Certificate (STC) ST01697SE as referenced in Boeing Service Bulletin 737-21-1149. **REVISION HISTORY** October 21, 2011 Original Issue: March 14, 2012 Revision 1:
**EFFECTIVITY** 737-900/-900ER Airplanes. Refer to Paragraph 1.A.1., Airplanes, in the original issue of this service bulletin for the list of affected airplanes. **APPROVAL** This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 21, 2011 737-53-1312 Revision 1: March 14, 2012 3 of 4**EXISTING INFORMATION** No existing information. **CHANGED INFORMATION** The following is the changed information in the service bulletin: In Paragraph 1.E., Compliance, a paragraph is added as follows: "For airplanes which have incorporated Boeing Business Jet (BBJ) Lower Cabin Altitude Supplemental Type Certificate (STC) ST01697SE (6500 feet maximum cabin altitude in lieu of 8000 feet) as referenced in Boeing Service Bulletin 737-21-1149, the flight cycle related compliance times are different from those specified in this service bulletin. All initial compliance times (thresholds) specified in flight cycles must be reduced to half of those specified in this service bulletin. All repeat interval compliance times specified in flight cycles must be reduced to one-quarter of those specified in this service bulletin."

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: October 21, 2011 737-53-1312 Revision 1: March 14, 2012 4 of 4 **BOEING SERVICE BULLETIN 737-53-1312**