2011-21668. Airworthiness Directives; The Boeing Company Model 757-200, -200PF, and -200CB Series Airplanes

AGENCY:

Federal Aviation Administration (FAA), DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

We propose to supersede an existing airworthiness directive (AD) that applies to the products listed above. The existing AD currently requires repetitive inspections of the shim installation between the engine strut vertical flange and bulkhead, and repair if necessary. The existing AD also requires, for certain airplanes, an inspection for cracking of the four critical fastener holes in the horizontal flange, and repair if necessary. Additionally, the existing AD requires that the existing action be performed on airplanes without conclusive records of previous inspections. Since we issued that AD, we have received reports of loose fasteners and cracks at the joint common to the aft torque bulkhead and strut-to-diagonal brace fitting and one report of such damage occurring less than 3,000 flight cycles after the last inspection. This proposed AD would reduce the repetitive inspection interval, and add repetitive detailed inspections for cracking of the bulkhead, and repair if necessary. This proposed AD would also provide an option, for certain airplanes, to extend the repetitive intervals by also doing repetitive ultrasonic inspections for cracking of the bulkhead, and repair if necessary. This proposed AD would also add an option for the high frequency eddy current inspection for cracking of the critical fastener holes, and repair if necessary. We are proposing this AD to detect and correct cracks, loose and broken bolts, and shim migration in the joint between the aft torque bulkhead and the strut-to-diagonal brace fitting, which could result in damage to the strut and consequent separation of the strut and engine from the airplane.

DATES:

We must receive comments on this proposed AD by October 11, 2011.

ADDRESSES:

You may send comments by any of the following methods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov. Follow the instructions for submitting comments.
• Fax: [phone].
• Mail: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590.
• Hand Delivery: Deliver to Mail address above between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; phone: [phone], extension 1; fax: [phone]; e-mail: [e-mail]; Internet: https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Examining the AD Docket

You may examine the AD docket on the Internet at http://www.regulations.gov;​; or in person at the Docket Management Facility between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The AD docket contains this proposed AD, the regulatory evaluation, any comments received, and other information. The street address for the Docket Office (phone: [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft Certification Office (ACO), FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: [phone]; fax: [phone]; e-mail: [e-mail].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to send any written relevant data, views, or arguments about this proposed AD. Send your comments to an address listed under the ADDRESSES section. Include “Docket No. FAA-2011-0724; Directorate Identifier 2010-NM-181-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of this proposed AD. We will consider all comments received by the closing date and may amend this proposed AD because of those comments.

We will post all comments we receive, without change, to http://www.regulations.gov, including any personal information you provide. We will also post a report summarizing each substantive verbal contact we receive about this proposed AD.

Discussion

On February 22, 2008, we issued AD 2008-05-10, Amendment 39-15404 (73 FR 11347, March 3, 2008), for certain Boeing Model 757-200, -200PF, and -200CB series airplanes powered by Rolls-Royce engines. That AD requires repetitive inspections of the shim installation between the engine strut vertical flange and bulkhead, and repair if necessary. That AD also requires, for certain airplanes, an inspection for cracking of the four critical fastener holes in the horizontal flange, and repair if necessary. That AD resulted from reports of cracking in the pylon under bolts that appear to be undamaged during the existing AD inspections. That AD also resulted from our determination that operators did not maintain records of previous inspections that are necessary to determine the appropriate corrective actions. We issued that AD to detect and correct cracks, loose and broken bolts, and shim migration in the joint between the aft torque bulkhead and the strut-to-diagonal brace fitting, which could result in damage to the strut and consequent separation of the strut and engine from the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2008-05-10, we have received reports of loose fasteners and cracks at the joint common to the aft torque bulkhead and strut-to-diagonal brace fitting and one report of such damage found fewer than 3,000 flight cycles after the last inspection.

Related Service Information

We reviewed Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010. This service information reduces the repetitive inspection interval to between 1,800 flight cycles and 3,000 flight cycles, depending on the airplane group and configuration. This service information also adds an optional ultrasonic inspection for the high frequency eddy current inspection to detect cracking of the critical fastener holes, and repairs if necessary. This service information adds procedures for repetitive detailed inspections for cracking of the bulkhead around the access door cutout and around the critical fasteners in the horizontal flange, and repair if necessary. This service information also provides an option, for certain airplanes, to extend the repetitive intervals by also doing repetitive ultrasonic inspections for cracking of the bulkhead around the fasteners in the horizontal flange, and repairs if necessary.

FAA's Determination

We are proposing this AD because we evaluated all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

Proposed AD Requirements

This proposed AD would retain all the requirements of AD 2008-05-10.

This proposed AD would reduce the repetitive inspection interval, and add repetitive detailed inspections for cracking of the bulkhead, and repair if necessary. This proposed AD would also provide an option, for certain airplanes, to extend the repetitive intervals by also doing repetitive ultrasonic inspections for cracking of the bulkhead, and repair if necessary. This proposed AD would also add an option for the high frequency eddy current inspection for cracking of the critical fastener holes, and repair if necessary.

Differences Between the Proposed AD and the Service Information

Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010, specifies to contact the manufacturer for instructions on how to repair certain conditions, but this proposed AD would require repairing those conditions in one of the following ways:

• In accordance with a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) whom we have authorized to make those findings.

Change to Existing AD

We have removed the “Service Bulletin Reference” paragraph from this proposed AD. That paragraph was identified as paragraph (f) in AD 2008-05-10. Instead, we have provided the full service bulletin citations throughout this proposed AD and re-identified subsequent paragraphs accordingly.

Costs of Compliance

We estimate that this proposed AD affects 309 airplanes of U.S. registry.

We estimate the following costs to comply with this proposed AD:

Estimated costs

Action	Labor cost	Parts cost	Cost per product	Cost on U.S. operators
Part I Inspection on fasteners and shims—vertical flange [retained actions from existing AD]	28 work-hours × $85 per hour = $2,380 per inspection cycle	$0	$2,380 per inspection cycle	$735,420 per inspection cycle.
Part II Inspection on fasteners—horizontal flange [retained actions from existing AD]	6 work-hours × $85 per hour = $510 per inspection cycle	0	$510 per inspection cycle	$157,590 per inspection cycle.
Part IV inspection on critical fasteners—horizontal flange [retained actions from existing AD]	6 work-hours × $85 per hour = $510 per inspection cycle	0	$510 per inspection cycle	$157,590 per inspection cycle.
Part II Additional inspection actions on fasteners—horizontal flange [new proposed action]	10 work-hours × $85 per hour = $850 per inspection cycle	0	$850 per inspection cycle	$262,650 per inspection cycle.
Part IV inspection on critical fasteners—horizontal flange [new proposed action]	8 to 22 work-hours × $85 per hour = $680 to $1,870 per inspection cycle	0	$680 to $1,870 per inspection cycle	$210,120 to $577,830 per inspection cycle.

We have received no definitive data that would enable us to provide cost estimates for the on-condition actions specified in this proposed AD.

Authority for This Rulemaking

Title 49 of the United States Code specifies the FAA's authority to issue rules on aviation safety. Subtitle I, section 106, describes the authority of the FAA Administrator. Subtitle VII, Aviation Programs, describes in more detail the scope of the Agency's authority.

We are issuing this rulemaking under the authority described in subtitle VII, part A, subpart III, section 44701, “General requirements.” Under that section, Congress charges the FAA with promoting safe flight of civil aircraft in air commerce by prescribing regulations for practices, methods, and procedures the Administrator finds necessary for safety in air commerce. This regulation is within the scope of that authority because it addresses an unsafe condition that is likely to exist or develop on products identified in this rulemaking action.

Regulatory Findings

We have determined that this proposed AD would not have federalism implications under Executive Order 13132. This proposed AD would not have a substantial direct effect 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.

For the reasons discussed above, I certify that the proposed regulation:

(1) Is not a “significant regulatory action” under Executive Order 12866,

(2) Is not a “significant rule” under the DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979),

(3) Will not affect intrastate aviation in Alaska, and

(4) Will not have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 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. The FAA amends § 39.13 by removing airworthiness directive (AD) 2008-05-10, Amendment 39-15404 (73 FR 11347, March 3, 2008), and adding the following new AD:

The Boeing Company: Docket No. FAA-2011-0724; Directorate Identifier 2010-NM-181-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by October 11, 2011.

Affected ADs

(b) This AD supersedes AD 2008-05-10, Amendment 39-15404.

Applicability

(c) This AD applies to Boeing Model 757-200, -200PF, and -200CB series airplanes; certificated in any category; line numbers 1 through 1048 inclusive; powered by Rolls-Royce engines.

Subject

(d) Joint Aircraft System Component (JASC)/Air Transport Association (ATA) of America Code 54, Nacelles/Pylons.

Unsafe Condition

(e) This AD was prompted by reports of loose fasteners and cracks at the joint common to the aft torque bulkhead and strut-to-diagonal brace fitting and one report of such damage occurring less than 3,000 flight cycles after the last inspection. We are issuing this AD to detect and correct cracks, loose and broken bolts, and shim migration in the joint between the aft torque bulkhead and the strut-to-diagonal brace fitting, which could result in damage to the strut and consequent separation of the strut and engine from the airplane.

Compliance

(f) Comply with this AD within the compliance times specified, unless already done.

Restatement of the Requirements of AD 2007-16-13 With Reduced Repetitive Intervals and New Optional Inspection Method

One-Time Inspection and Repair With Optional Inspection Method

(g) For airplanes identified in paragraphs (g)(1) and (g)(2) of this AD: Within 90 days after August 24, 2007 (the effective date of AD 2007-16-13), do a high frequency eddy current (HFEC) inspection for cracking of the four critical fastener holes in the horizontal flange and, before further flight, do all applicable repairs, in accordance with Part IV of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007; or Revision 4, dated June 24, 2010; except as required by paragraph (k) of this AD. As of the effective date of this AD, only Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010, may be used. Doing an ultrasonic inspection for cracking of the fasteners, in accordance with Part IV of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010, is an acceptable method for compliance with the HFEC inspection requirement of this paragraph.

(1) Airplanes on which findings on the horizontal or vertical fasteners or the shims led to a rejection of any fastener during the actions specified in Boeing Alert Service Bulletin 757-54A0047, dated November 13, 2003; or Boeing Service Bulletin 757-54A0047, Revision 1, dated March 24, 2005.

(2) Airplanes that had equivalent findings prior to Boeing Alert Service Bulletin 757-54A0047, dated November 13, 2003, except for findings on airplanes identified as Group 1, Configuration 2, in Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, that were prior to the incorporation of Boeing Service Bulletin 757-54-0035.

Repetitive Inspection and Repair

(h) At the applicable initial times specified in paragraph 1.E., “Compliance” of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, except as required by paragraphs (i) and (j) of this AD: Do the inspections specified in paragraphs (h)(1), (h)(2), and (h)(3) of this AD, and before further flight, do all the applicable related investigative actions and repairs, by doing all the actions specified in Parts I and II of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007; or by doing all the actions in Part I and in Step 2 of Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010; except as required by paragraph (k) of this AD. As of the effective date of this AD, only Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010, may be used. Repeat the inspections required by this paragraph at the times specified in paragraph (h)(4) of this AD.

(1) Do detailed inspections of the shim installations between the vertical flange and bulkhead to determine if there are signs of movement.

(2) Do detailed inspections of the four fasteners in the vertical flange to determine if there are signs of movement or if there are gaps under the head or collar.

(3) Do detailed inspections of the fasteners that hold the strut to the horizontal flange of the strut-to-diagonal brace fitting to determine if there are signs of movement or if there are gaps under the head or collar.

(4) Repeat the inspections required by paragraph (h) of this AD at the earlier of the times specified in paragraphs (h)(4)(i) and (h)(4)(ii) of this AD. Thereafter, repeat the inspections at intervals not to exceed the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010.

(i) At intervals not to exceed the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007.

(ii) At intervals not to exceed the applicable intervals specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010; or within 90 days after the effective date of this AD, whichever occurs later.

Exceptions to Alert Service Bulletin Procedures

(i) Where Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, specifies a compliance time relative to “the date on this service bulletin,” this AD requires compliance within the corresponding specified time relative to the effective date of AD 2007-16-13.

(j) Where Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, specifies a compliance time relative to the “date of issuance of airworthiness certificate,” this AD requires compliance within the corresponding time relative to the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness.

(k) If any crack is found during any inspection required by this AD, and Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007; or Revision 4, dated June 24, 2010; specifies to contact Boeing for appropriate action: Before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

Restatement of the Requirements of AD 2008-05-10

Inspection/Repair for Airplanes for Which There Are No Conclusive Inspection Records

(l) For airplanes for which there are no conclusive records showing no loose or missing fasteners during previous inspections done in accordance with the requirements of AD 2007-16-13, Amendment 39-15152 (72 FR 44753, August 9, 2007); or AD 2005-12-04, Amendment 39-14120 (70 FR 34313 June 14, 2005): Do the actions specified in paragraphs (l)(1) and (l)(2) of this AD, at the times specified in those paragraphs, as applicable.

(1) Within 90 days after March 18, 2008 (the effective date of AD 2008-05-10), do the actions specified in paragraph (g) of this AD, except as required by paragraph (k) of this AD.

(2) At the applicable initial times specified in paragraph 1.E., “Compliance,” of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, do the actions specified in paragraph (h) of this AD, except as required by paragraphs (j) and (m) of this AD. And, before further flight, do all applicable related investigative actions and repairs, by doing all the actions specified in Parts I and II of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007; or in Part 1 and in Step 2 of Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010; except as required by paragraph (k) of this AD. As of the effective date of this AD, only Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010, may be used. Repeat the actions specified in paragraph (h) of this AD at the times specified in paragraph (h)(4) of this AD.

Exception to Alert Service Bulletin Procedures

(m) Where Boeing Alert Service Bulletin 757-54A0047, Revision 3, dated June 27, 2007, specifies a compliance time relative to “the date on this service bulletin,” this AD requires compliance within the corresponding specified time relative to the effective date of AD 2008-05-10.

Credit for Actions Done in Accordance With Previous Service Information

(n) Except for the actions specified in paragraph (l) of this AD, actions done before March 18, 2008, in accordance with Boeing Service Bulletin 757-54A0047, Revision 1, dated March 24, 2005; or Boeing Alert Service Bulletin 757-54A0047, Revision 2, dated January 31, 2007; are considered acceptable for compliance with the corresponding actions specified in this AD.

(o) An inspection and corrective actions done before June 29, 2005 (the effective date of AD 2005-12-04), in accordance with paragraph (b) or (c), as applicable, of AD 2004-12-07, are acceptable for compliance with the initial inspection requirement of paragraph (h) of this AD.

An Acceptable Method of Compliance With Certain Requirements of AD 2004-12-07

(p) Accomplishing the actions specified in paragraphs (g) and (h) of this AD terminates the requirements specified in paragraphs (b) and (c) of AD 2004-12-07.

New Requirements of This AD

Repetitive Inspections and Repair

(q) At the applicable initial compliance times specified in paragraph (r) of this AD: Do the applicable actions specified in paragraph (q)(1) or (q)(2) of this AD, in accordance with Step 3 of Part II of the Accomplishment Instructions of Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010. If no cracking is found, repeat the inspections thereafter at intervals not to exceed the applicable intervals specified in paragraph 1.E., “Compliance,” of the Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010. If any crack is found during any inspection required by this paragraph, before further flight, repair the crack using a method approved in accordance with the procedures specified in paragraph (s) of this AD.

(1) For Group 1, Configuration 1 airplanes identified in Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010: Do the actions specified in paragraph (q)(1)(i) or (q)(1)(ii) of this AD.

(i) Do a detailed inspection for cracking of the bulkhead and in the area around the access door cutout and around the critical fasteners in the horizontal flange.

(ii) Do detailed inspection for cracking of the bulkhead and in the area around the access door cutout and around the critical fasteners in the horizontal flange, and do an ultrasonic inspection for cracking of the bulkhead around the fasteners in the horizontal flange. Doing the actions in this paragraph extends the repetitive intervals of the inspections required by paragraph (q) of this AD.

(2) For Group 1, Configuration 2 airplanes; and Group 2 airplanes; identified in Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010: Do a detailed inspection for cracking of the bulkhead and in the area around the access door cutout and around the critical fasteners in the horizontal flange.

(r) At the applicable times specified in paragraphs (r)(1) and (r)(2) of this AD, do the actions required by paragraph (q) of this AD.

(1) For Group 1, Configuration 1 airplanes identified in Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010: At the later of the times specified in paragraph (r)(1)(i) or (r)(1)(ii) of this AD.

(i) Within 1,800 flight cycles after accomplishing the most recent inspection required by paragraph (h) of this AD.

(ii) Within 90 days after the effective date of this AD.

(2) For Group 1, Configuration 2 airplanes; and Group 2 airplanes; identified in Boeing Alert Service Bulletin 757-54A0047, Revision 4, dated June 24, 2010: At the later of the times specified in paragraph (r)(2)(i) or (r)(2)(ii) of this AD.

(i) Within 3,000 flight cycles after accomplishing the most recent inspection required by paragraph (h) of this AD.

(ii) Within 90 days after the effective date of this AD.

Alternative Methods of Compliance (AMOCs)

(s)(1) The Manager, Seattle Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. In accordance with 14 CFR 39.19, send your request to your principal inspector or local Flight Standards District Office, as appropriate. If sending information directly to the manager of the ACO, send it to the attention of the person identified in the Related Information section of this AD. Information may be e-mailed to: [e-mail].

(2) Before using any approved AMOC, notify your appropriate principal inspector, or lacking a principal inspector, the manager of the local flight standards district office/certificate holding district office.

(3) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD if it is approved by the Boeing Commercial Airplanes Organization Designation Authorization (ODA) that has been authorized by the Manager, Seattle ACO to make those findings. For a repair method to be approved, the repair must meet the certification basis of the airplane and the approval must specifically refer to this AD.

(4) AMOCs approved previously in accordance with AD 2004-12-07 are approved as AMOCs for the corresponding provisions of this AD.

(5) AMOCs approved previously in accordance with AD 2005-12-04 are approved as AMOCs for the corresponding provisions of this AD.

(6) AMOCs approved previously in accordance with AD 2007-16-13 are approved as AMOCs for the corresponding provisions of this AD.

(7) AMOCs approved previously in accordance with AD 2008-05-10 are approved as AMOCs for the corresponding provisions of this AD.

Related Information

(t) For more information about this AD, contact Nancy Marsh, Aerospace Engineer, Airframe Branch, ANM-120S, Seattle Aircraft Certification Office (ACO), FAA, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone [phone]; fax [phone]; e-mail: [e-mail].

(u) For service information identified in this AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; phone: [phone], extension 1; fax: [phone]; e-mail: [e-mail]; Internet: https://www.myboeingfleet.com. You may review copies of the referenced service information at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington. For information on the availability of this material at the FAA, call 425-227-1221.

Issued in Renton, Washington, on August 12, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.