2011-8407. Airworthiness Directives; The Boeing Company Model 757 Airplanes

AGENCY:

Federal Aviation Administration (FAA), Department of Transportation (DOT).

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to supersede an existing airworthiness directive (AD) that applies to all Model 757 airplanes. The existing AD currently requires revising the Airworthiness Limitations (AWLs) section of the Instructions for Continued Airworthiness by incorporating new limitations for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. That AD also requires the initial inspection of certain repetitive AWL inspections to phase-in those inspections, and repair if necessary. This proposed AD would require actions that were provided previously as optional actions, and would require a certain initial inspection to be accomplished for a revised AWL. This proposed AD results from a report that an AWL required by the existing AD must be revised. We are proposing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

DATES:

We must receive comments on this proposed AD by May 23, 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: U.S. Department of Transportation, Docket Operations, M-30, West Building Ground Floor, Room W12-140, 1200 New Jersey Avenue, SE., Washington, DC 20590, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

For service information identified in this proposed AD, contact Boeing Commercial Airplanes, Attention: Data & Services Management, P.O. Box 3707, MC 2H-65, Seattle, Washington 98124-2207; telephone [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 (telephone [phone]) is in the ADDRESSES section. Comments will be available in the AD docket shortly after receipt.

FOR FURTHER INFORMATION CONTACT:

Tak Kobayashi, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle Aircraft Certification Office, 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-2011-0304; Directorate Identifier 2010-NM-103-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 April 29, 2008, we issued AD 2008-10-11, amendment 39-15517 (73 FR 25974, May 8, 2008), for all Model 757 series airplanes. That AD requires revising the Airworthiness Limitations (AWLs) section of the Instructions for Continued Airworthiness by incorporating new limitations for fuel tank systems to satisfy Special Federal Aviation Regulation No. 88 requirements. That AD also requires the initial inspection of certain repetitive AWL inspections to phase-in those inspections, and repair if necessary. That AD resulted from a design review of the fuel tank systems. We issued that AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2008-10-11, we received a report from the manufacturer that AWL No. 28-AWL-03, as specified in Boeing Temporary Revision (TR) 09-008, dated March 2008, contained incorrect information. Boeing TR 09-008 was published as Section 9 of the Boeing 757 Maintenance Planning Data (MPD) Document, D622N001-9, Revision March 2008, and was referenced by AD 2008-10-11. Use of that AWL may result in not detecting defects in the fuel quantity indicating system (FQIS) wiring shield. Boeing issued Boeing TR 09-010, dated July 2010, which was published as Section 9 of the Boeing 757 MPD Document, D622N001-9, Revision July 2010. That document also revises other AWLs referenced by AD 2008-10-11.

Since we issued that AD, we have also determined that it is necessary to clarify the AD's intended effect on spare and on-airplane fuel tank system components, regarding the use of maintenance manuals and instructions for continued airworthiness.

Section 91.403(c) of the Federal Aviation Regulations (14 CFR 91.403(c)) specifies the following:

No person may operate an aircraft for which a manufacturer's maintenance manual or instructions for continued airworthiness has been issued that contains an airworthiness limitation section unless the mandatory * * * procedures * * * have been complied with.

Critical design configuration control limitations (CDCCLs) are airworthiness limitation requirements to preserve a critical ignition source prevention feature of the fuel tank system design that is necessary to prevent the occurrence of an unsafe condition. The purpose of a CDCCL is to provide instruction to retain the critical ignition source prevention feature during configuration changes that may be caused by alterations, repairs, or maintenance actions. A CDCCL is not a periodic inspection.

Some operators have questioned whether existing components affected by the new CDCCLs must be reworked. We did not intend for the AD to retroactively require rework of components that had been maintained using acceptable methods before the effective date of the AD. Owners and operators of the affected airplanes therefore are not required to rework affected components identified as airworthy or installed on the affected airplanes before the required revisions of the maintenance program. But once the CDCCLs are incorporated into the maintenance program, future maintenance actions on components must be done in accordance with those CDCCLs.

Explanation of Changes to AD 2008-10-11

AD 2008-10-11 allowed the inclusion of AWLs No. 28-AWL-25 and 28-AWL-26 as an optional action. We have determined that those AWLs must be required. We have added that requirement in paragraph (l) of this proposed AD to require those AWLs and paragraphs (n) and (o) of this proposed AD to clarify the required compliance times for those AWLs.

We have removed the “Service Information” reference paragraph from this proposed AD. That paragraph was identified as paragraph (f) in AD 2008-10-11. Instead, we have provided the full service information citations throughout this NPRM.

AD 2008-10-11 allowed the use of alternative inspections, intervals, or CDCCLs if they are part of a later revision of Boeing TR 09-008, dated March 2008, to Section 9 of the Boeing 757 MPD Document, D622N001-9. AD 2008-10-11 also allowed the use of later revisions of Section 9 of the Boeing 757 MPD Document, D622N001-9. Those provisions have been removed from this proposed AD. We have removed the references to “a later revision” or “later FAA-approved revisions” of specific service documents to be consistent with FAA policy and with Office of the Federal Register regulations for approving materials that are incorporated by reference. Affected operators, however, may request approval to use a later revision or an alternative CDCCL, inspection, or interval that is part of a later revision of the referenced service documents as an alternative method of compliance, under the provisions of paragraph (u) of this AD.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to develop on other airplanes of the same type design. For this reason, we are proposing this AD, which would supersede AD 2008-10-11 and would retain the requirements of the existing AD with revised service information. This proposed AD would also require actions that were previously provided as optional actions in the existing AD.

Costs of Compliance

There are about 990 airplanes of the affected design in the worldwide fleet. The following table provides the estimated costs for U.S. operators to comply with this proposed AD.

Estimated Costs

Action	Work hours	Average labor rate per hour	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
AWLs revision (required by AD 2008-10-11)	8	$85	$680	639	$434,520
Inspections (required by AD 2008-10-11)	8	85	680	639	434,520
AWLs revision (new proposed action)	1	85	85	639	54,315

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); and

(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 amendment 39-15517 (73 FR 25974, May 8, 2008) and adding the following new AD:

The Boeing Company: Docket No. FAA-2011-0304; Directorate Identifier 2010-NM-103-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by May 23, 2011.

Affected ADs

(b) This AD supersedes AD 2008-10-11, Amendment 39-15517. Certain requirements of this AD terminate certain requirements of AD 2008-11-07, Amendment 39-15529; AD 2008-06-03, Amendment 39-15415; and AD 2009-06-20, Amendment 39-15857.

Applicability

(c) This AD applies to all The Boeing Company Model 757-200, -200PF, -200CB, and -300 series airplanes, certificated in any category.

Note 1:

This AD requires revisions to certain operator maintenance documents to include new actions (e.g., inspections) and/or Critical Design Configuration Control Limitations (CDCCLs). Compliance with these actions and/or CDCCLs is required by 14 CFR 91.403(c). For airplanes that have been previously modified, altered, or repaired in the areas addressed by these inspections, the operator may not be able to accomplish the actions described in the revisions. In this situation, to comply with 14 CFR 91.403(c), the operator must request approval of an alternative method of compliance (AMOC) according to paragraph (u) of this AD. The request should include a description of changes to the required actions that will ensure the continued operational safety of the airplane.

Subject

(d) Air Transport Association (ATA) of America Code 28: Fuel.

Unsafe Condition

(e) This AD results from a design review of the fuel tank systems. The Federal Aviation Administration is issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, in combination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss of the airplane.

Compliance

(f) You are responsible for having the actions required by this AD performed within the compliance times specified, unless the actions have already been done.

Restatement of Requirements of AD 2008-10-11, With Revised Service Information

Revision of Airworthiness Limitations (AWLs) Section

(g) Before December 16, 2008, revise the AWLs section of the Instructions for Continued Airworthiness (ICA) by incorporating the information in the subsections specified in paragraphs (g)(1) through (g)(3) of this AD into the MPD; except that the initial inspections specified in Table 1 of this AD must be done at the compliance times specified in Table 1. Accomplishing the requirements of paragraph (l) of this AD terminates the requirements of this paragraph.

(1) Subsection E, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” of Boeing Temporary Revision (TR) 09-008, dated March 2008, to Section 9 of the Boeing 757 Maintenance Planning Data (MPD) Document, D622N001-9.

(2) Subsection F, “PAGE FORMAT: SYSTEMS AIRWORTHINESS LIMITATIONS,” of Boeing TR 09-008, dated March 2008, to Section 9 of the Boeing 757 MPD Document, D622N001-9.

(3) Subsection G, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEM AWLs,” AWLs No. 28-AWL-01 through No. 28-AWL-24 inclusive, of Boeing TR 09-008, dated March 2008, to Section 9 of the Boeing 757 MPD Document, D622N001-9. As an optional action, AWLs No. 28-AWL-25 and No. 28-AWL-26, as identified in Subsection G of Boeing TR 09-008, dated March 2008, to Section 9 of the Boeing 757 MPD Document, D622N001-9, also may be incorporated into the AWLs section of the ICA.

Initial Inspections and Repair

(h) Do the inspections specified in Table 1 of this AD at the compliance time identified in Table 1 of this AD, and repair any discrepancy, in accordance with Subsection G of Boeing TR 09-008, dated March 2008, or Boeing TR 09-010, dated July 2010, to Section 9 of the Boeing 757 MPD Document, D622N001-9, except as required by paragraph (m) of this AD. The repair must be done before further flight. Accomplishing the inspections identified in Table 1 of this AD as part of a maintenance program before the applicable compliance time specified in Table 1 of this AD constitutes compliance with the requirements of this paragraph. After the effective date of this AD, only Boeing TR 09-010, dated July 2010, to Section 9 of the Boeing 757 Maintenance Planning Data (MPD) Document, D622N001-9, may be used.

Table 1—Initial Inspections

AWL No.	Description	Compliance time (whichever occurs later)
		Threshold	Grace period
(1) 28-AWL-01	A detailed inspection of external wires over the center fuel tank for damaged clamps, wire chafing, and wire bundles in contact with the surface of the center fuel tank	Within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness	Within 72 months after June 12, 2008 (the effective date of AD 2008-10-11).
(2) 28-AWL-03	A special detailed inspection of the lightning shield to ground termination on the out-of-tank fuel quantity indicating system to verify functional integrity	Within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness	Within 24 months after June 12, 2008.
(3) 28-AWL-14	A special detailed inspection of the fault current bond of the fueling shutoff valve actuator of the center wing tank to verify electrical bond	Within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness	Within 60 months after June 12, 2008.

Note 2:

For the purposes of this AD, a detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirror, magnifying lenses, etc., may be necessary. Surface cleaning and elaborate procedures may be required.”

Note 3:

For the purposes of this AD, a special detailed inspection is: “An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. The examination is likely to make extensive use of specialized inspection techniques and/or equipment. Intricate cleaning and substantial access or disassembly procedure may be required.”

No Alternative Inspections, Inspection Intervals, or CDCCLs

(i) After accomplishing the actions specified in paragraphs (g) and (h) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are approved as an AMOC in accordance with the procedures specified in paragraph (u) of this AD.

Credit for Actions Done According to Previous Revisions of the MPD

(j) Actions done before June 12, 2008, in accordance with Section 9 of the Boeing 757 MPD Document, D622N001-9, Revision March 2006; Revision October 2006; Revision January 2007; or Revision November 2007; are acceptable for compliance with the corresponding requirements of paragraphs (g) and (h) of this AD.

Terminating Action for AD 2008-06-03, Amendment 39-15415

(k) Incorporating AWLs No. 28-AWL-23, No. 28-AWL-24, and No. 28-AWL-25 into the AWLs section of the ICA in accordance with paragraph (g)(3) of this AD or the maintenance program in accordance with paragraph (l)(3) of this AD terminates the action required by paragraph (h)(2) of AD 2008-06-03. After the effective date of this AD, only paragraph (l)(3) of this AD may be used.

New Requirements of This AD

Revision of Airworthiness Limitations (AWLs) Section

(l) Within 6 months after the effective date of this AD, revise the maintenance program by incorporating the information in the subsections specified in paragraphs (l)(1) through (l)(3) of this AD. Accomplishing the actions required by this paragraph terminates the requirements of paragraph (g) of this AD.

(1) Subsection E, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEMS,” of Boeing TR 09-010, dated July 2010, to Section 9 of the Boeing 757 MPD Document, D622N001-9.

(2) Subsection F, “PAGE FORMAT: FUEL SYSTEMS AIRWORTHINESS LIMITATIONS,” of Boeing TR 09-010, dated July 2010, to Section 9 of the Boeing 757 MPD Document, D622N001-9.

(3) Subsection G, “AIRWORTHINESS LIMITATIONS—FUEL SYSTEM AWLs,” AWLs No. 28-AWL-01 through No. 28-AWL-26 inclusive, of Boeing TR 09-010, dated July 2010, to Section 9 of the Boeing 757 MPD Document, D622N001-9.

Compliance Time for AWL No. 28-AWL-03

(m) The initial compliance time for AWL No. 28-AWL-03 of Boeing TR 09-010, dated July 2010, to Section 9 of Boeing 757 MPD Document, D622N001-9, is within 120 months since the date of issuance of the original standard airworthiness certificate or the date of issuance of the original export certificate of airworthiness, or within 24 months after the effective date of this AD, whichever occurs later. Accomplishing the actions required by this paragraph terminates the requirements of paragraph (h)(2) of this AD.

Initial Inspection Compliance Times for AWL No. 28-AWL-25 and 28-AWL-26

(n) The initial inspection compliance time for AWL No. 28-AWL-25 of Boeing TR 09-010, dated July 2010, to Section 9 of Boeing 757 MPD Document, D622N001-9, is within 72 months after accomplishing Boeing Service Bulletin 757-28A0088.

(o) The initial inspection compliance time for AWL No. 28-AWL-26 of Boeing TR 09-010, dated July 2010, to Section 9 of Boeing 757 MPD Document, D622N001-9, is within 12 months after accomplishing Boeing Service Bulletin 757-28A0105.

No Alternative Inspections, Inspection Intervals, or CDCCLs

(p) After accomplishing the actions specified in paragraph (l) of this AD, no alternative inspections, inspection intervals, or CDCCLs may be used unless the inspections, intervals, or CDCCLs are approved as an AMOC in accordance with the procedures specified in paragraph (u) of this AD.

Terminating Action for AD 2008-11-07, Amendment 39-15529

(q) Incorporating AWLs No. 28-AWL-20 and No. 28-AWL-26 into the maintenance program in accordance with paragraph (l)(3) of this AD terminates the actions required by paragraphs (j) and (m) of AD 2008-11-07.

Terminating Action for AD 2009-06-20, Amendment 39-15857

(r) Incorporating AWL No. 28-AWL-22 into the maintenance program in accordance with paragraph (l)(3) of this AD terminates the actions required by paragraph (h) of AD 2009-06-20.

Credit for Actions Accomplished in Accordance With Previous Service Information

(s) Actions done before the effective date of this AD in accordance with Section 9 of the Boeing 757 MPD Document, D622N001-9, Revision December 2008, is acceptable for compliance with the corresponding requirements of this AD.

(t) Actions done before the effective date of this AD in accordance with Subsection G of Boeing TR 09-008, dated March 2008, to Section 9 of the Boeing 757 MPD Document, D622N001-9, is acceptable for compliance with the requirements of paragraphs (n) and (o) of this AD.

Explanation of CDCCL Requirements

Note 4:

Notwithstanding any other maintenance or operational requirements, components that have been identified as airworthy or installed on the affected airplanes before the revision of the maintenance program, as required by paragraphs (g) and (l) of this AD, do not need to be reworked in accordance with the CDCCLs. However, once the maintenance program has been revised, future maintenance actions on these components must be done in accordance with the CDCCLs.

Alternative Methods of Compliance (AMOCs)

(u)(1) The Manager, Seattle Aircraft 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) AMOCs approved previously for AD 2008-10-11 are approved as AMOCs for the corresponding provisions of this AD.

Related Information

(v) For more information about this AD, contact Tak Kobayashi, Aerospace Engineer, Propulsion Branch, ANM-140S, FAA, Seattle ACO, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; phone: [phone]; fax: [phone]; e-mail: [e-mail].

(w) 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; telephone [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 March 25, 2011.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.