AD 98-19-10

This amendment adopts a new airworthiness directive (AD) that is applicable to CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan engines. This action requires, on aircraft with two affected engines installed, removal of one affected engine from an aircraft, and replacement with a serviceable engine, or replacement of a suspect accessory gearbox (AGB) starter gearshaft with a serviceable gearshaft within 350 hours time in service (TIS) after the effective date of this AD, or by September 1, 1998, whichever occurs first. This action also requires, on aircraft with only one affected engine installed, removal of the affected engine from the aircraft, and replacement with a serviceable engine, or replacement of the suspect starter gearshaft with a serviceable gearshaft within 2,100 hours TIS after the effective date of this AD, or by February 1, 1999, whichever occurs first. This amendment is prompted by reports of two inflight engine shutdowns caused by an AGB starter gearshaft failure. The actions specified in this AD are intended to prevent an AGB starter gearshaft failure, which can result in an inflight engine shutdown, and on aircraft with two affected engines installed, possible dual inflight engine shutdown and forced landing.

Final rule; request for comments.

98-19-10 CFM International: Amendment 39-10752 Docket 98-ANE-44-AD.
Applicability: CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan engines, having any of the engine serial numbers (ESNs) identified in Table 1 of CFMI CFM56-3/-3B/-3C Service Bulletin (SB) No. 72-877, Revision 1, dated June 15, 1998. These engines are installed on but not limited to Boeing 737 series aircraft.
Note 1: This airworthiness directive (AD) applies to each engine identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For engines that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (d) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.
Compliance: Required as indicated, unless accomplished previously.
To prevent an accessory gearbox (AGB) starter gearshaft failure, which can result in an inflight engine shutdown, and on aircraft with two affected engines installed, possible dual inflight engine shutdown and forced landing, accomplish the following:
(a) On aircraft with two affected engines installed, remove one affected engine from the aircraft, and replace with a serviceable engine not identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-877, Revision 1, dated June 15, 1998, or replace the suspect starter gearshaft on one of the engines with a serviceable gearshaft, in accordance with the Accomplishment Instructions of CFMI CFM56-3/-3B/-3C SB No. 72-877, Revision 1, dated June 15, 1998; within 350 hours time in service (TIS) after the effective date of this AD, or by October 1, 1998, whichever occurs first. Thereafter, for the remaining engine, replace suspect starter gearshafts in accordance with paragraph (b) of this AD.
(b) On aircraft with only one affected engine installed, remove the affected engine from the aircraft, and replace with a serviceable engine not identified by ESN in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-877, Revision 1, dated June 15, 1998, or replace the suspect starter gearshaft with a serviceable gearshaft, in accordance with the Accomplishment Instructions of CFMI CFM56-3/-3B/-3C SB No. 72-877, Revision 1, dated June 15, 1998; within 2,100 hours TIS after the effective date of this AD, or by February 1, 1999, whichever occurs first.
(c) Report within 5 working days of replacement of the starter gearshaft to the FAA if the ESN listed in Table 1 of CFMI CFM56-3/-3B/-3C SB No. 72-877, Revision 1, dated June 15, 1998, does not directly correspond to the adjoining starter gearshaft serial number to verify that all affected parts have been removed from service. Report to the Manager, Engine Certification Office, FAA, Engine and Propeller Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; Fax (781) 238-7199. Reporting requirements have been approved by the Office of Management and Budget and assigned OMB control number 2120-0056.
(d) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Engine Certification Office. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Engine Certification Office.
Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Engine Certification Office.
(e) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.
(f) The actions required by this AD shall be done in accordance with the following CFMI CFM56-3/-3B/-3C SB:

Document No.
Pages
Revision
Date
72-877
1-49
1
June 15, 1998
Total pages: 49.

This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from CFM International, Technical Publications Department, 1 Neumann Way, Cincinnati, OH 45215; telephone (513) 552-2981, fax (513) 552-2816. Copies may be inspected at the FAA, New England Region, Office of the Regional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(g) This amendment becomes effective on September 28, 1998.

The Federal Aviation Administration (FAA) has received reports of two inflight engine shutdowns on CFM International (CFMI) CFM56-3, -3B, and -3C series turbofan engines. The investigation revealed that the inflight engine shutdowns were caused by an accessory gearbox (AGB) starter gearshaft failure. The investigation revealed that the gearshafts failed due to inadequate fatigue capability caused by high residual tensile stresses introduced during the manufacturing process, coupled with the elimination of shotpeening in the gearshaft hub. The manufacturing process has since been modified. The starter gearshaft, part number 335-302-503-0, involved in the events are included in a lot of 426 parts that have since been identified by the manufacturer as being installed on engines identified by engine serial number (ESN). This condition, if not corrected, could result in an AGB starter gearshaft failure, which can result in an inflight engine shutdown, and onaircraft with two affected engines installed, possible dual inflight engine shutdown and forced landing.
The FAA has reviewed and approved the technical contents of CFMI CFM56-3/-3B/-3C Service Bulletin (SB) No. 72-877, Revision 1, dated June 15, 1998, that describes procedures for identification of affected engines by ESN, and replacement of a suspect starter gearshaft with a serviceable part.
Since an unsafe condition has been identified that is likely to exist or develop on other engines of the same type design, this AD is being issued to prevent a dual inflight engine shutdown. This AD requires, within 350 hours time in service (TIS) after the effective date of this AD, or by October 1, 1998, whichever occurs first, on aircraft with two affected engines installed, removal of one affected engine from an aircraft, and replacement with a serviceable engine, or replacement of a suspect starter gearshaft with a serviceable part. This AD also requires, within 2,100 hours TIS after the effective date of this AD, or by February 1, 1999, whichever occurs first, on aircraft with only one affected engine installed, removal of the affected engine from the aircraft, and replacement with a serviceable engine, or removal of the suspect starter gearshaft and replacement with a serviceable part. The calendar end-dates were determined based upon risk analysis and parts availability. In addition, this AD requires reporting to the FAA if the ESN listed in Table 1 of the SB does not directly correspond to the adjoining starter gearshaft serial number in order to verify that all affected parts have been removed from service. The actions are required to be accomplished in accordance with the SB described previously.
Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.Comments Invited
Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule thatmight suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 98-ANE-44-AD." The postcard will be date stamped and returned to the commenter.
The regulations adopted herein will not have substantial direct effects on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Therefore, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES." List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.
Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by theAdministrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows: PART 39 - AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new airworthiness directive: