E9-17448. Airworthiness Directives; Boeing Model 747-200F, 747-200C, 747-400, 747-400D, and 747-400F Series 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 Boeing Model 747-200F, 747-200C, 747-400, 747-400D, and 747-400F series airplanes. The existing AD currently requires repetitive inspections for cracking of certain fuselage internal structure (i.e., Sections 42 and 46 fuselage frames, upper deck floor beams, electronic bay access door cutout, nose wheel well, and main entry doors and door cutouts), and repair if necessary. This proposed AD would require additional repetitive inspections for cracking of certain fuselage structure (i.e., Section 41 fuselage frames where they connect to upper deck floor beams, and section 41 fuselage frames between stringer (S-8 and S-12), and related investigative/corrective actions if necessary. This proposed AD would also reduce the inspection threshold and repetitive inspection intervals for certain airplanes. This proposed AD results from fatigue tests and analysis by Boeing that identified additional areas of the fuselage where fatigue cracks can occur. We are proposing this AD to prevent the loss of structural integrity of the fuselage, which could result in rapid depressurization of the airplane.

DATES:

We must receive comments on this proposed AD by September 8, 2009.

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 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 or 425-227-1152.

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:

Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone].

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-2009-0655; Directorate Identifier 2008-NM-192-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 16, 2006, we issued AD 2006-05-02, amendment 39-14499 (71 FR 10605, March 2, 2006), for all Boeing Model 747-200F, 747-200C, 747-400, 747-400D, and 747-400F series airplanes. That AD requires repetitive inspections for cracking of certain fuselage internal structure, and repair if necessary. That AD resulted from fatigue tests and analysis that identified areas of the fuselage where fatigue cracks can occur. We issued that AD to prevent the loss of the structural integrity of the fuselage, which could result in rapid depressurization of the airplane.

Actions Since Existing AD Was Issued

Since we issued AD 2006-05-02, Boeing has conducted an additional analysis that shows that Section 41 fuselage frames in the areas attached to the upper deck floor beams are also prone to fatigue cracking. Cracking of the frames was found on the fatigue test airplane at about 40,000 total pressure cycles. As a result of the cracking, we have determined that additional inspections are necessary, as specified in the service information described below. In addition, for certain airplanes, we have determined that it is necessary to reduce the compliance time for certain inspections.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008 (“Revision 1 of the service bulletin”). We referred to Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004, in AD 2006-05-02 as the appropriate source of service information for doing the actions required by that AD. Revision 1 of the service bulletin retains the procedures from the original issue, and adds the repetitive inspections for cracking in the additional areas listed in the table titled “New Service Bulletin Procedures.”

New Service Bulletin Procedures

Revision 1 of the service bulletin adds procedures for repetitive detailed inspections for cracking of—	For airplanes identified as these groups in Revision 1 of the service bulletin—
Area 1 (upper deck floor beams)—Inspections are added for the fuselage frames at body station (BS) 260 to 520 in areas where the upper deck floor beams are attached	1 through 7 inclusive, and 9 through 10 inclusive.
Area 6 (main entry door cutouts)—Inspections are added for the fuselage frames at BS 400 to 500 in areas above the main entry door 1 cutouts from the upper chord of the upper deck floor beams to stringer 8	1 through 7 inclusive.

The compliance times for airplane groups 1 through 7 and 9 through 10 remain the same as in AD 2006-05-02 for all inspections: 22,000 or 25,000 total flight cycles (depending on the inspection area and airplane configuration), with a repetitive interval of 3,000 flight cycles. For the inspection of additional areas, the service bulletin specifies a compliance time of 22,000 total flight cycles or 1,000 flight cycles after the date of Revision 1 of the service bulletin.

No new inspections are added for Group 8 airplanes specified in Revision 1 of the service bulletin, although certain inspections required by AD 2006-05-02 continue at a reduced threshold. (These airplanes were identified as Group 1 in Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004.) Furthermore, for Group 8 airplanes, the service bulletin removed the inspection requirements for Areas 2 and 5.

For Group 8 airplanes, the service bulletin specifies a reduced compliance time and reduced repetitive interval for continuing certain existing inspections. The compliance time for the initial inspection ranges from 15,000 total flight cycles to 22,000 total flight cycles (depending on the inspection area), or 1,000 flight cycles after the date of Revision 1 of the service bulletin, whichever occurs later. The repetitive interval ranges from intervals not to exceed 1,500 flight cycles to intervals not to exceed 3,000 flight cycles (depending on the inspection area).

The service bulletin specifies repairing any crack before further flight per the service bulletin or per repair data obtained by contacting Boeing.

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 2006-05-02 and would retain the requirements of the existing AD. This proposed AD would also require additional inspections for certain airplanes, a revised inspection for certain airplanes, and a reduced compliance time for certain other airplanes.

Costs of Compliance

There are about 640 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. The average labor rate is $80 per work hour.

Estimated Costs

Action	Work hours	Parts	Cost per airplane	Number of U.S.-registered airplanes	Fleet cost
Inspections (required by AD 2006-05-02)	260	None required	$20,800 per inspection cycle	71	$1,476,800 per inspection cycle.
Inspections of additional areas (new proposed action)	7	None required	$560 per inspection cycle	71	$39,760 per inspection cycle.

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 have a significant economic impact, positive or negative, on a substantial number of small entities under the criteria of the Regulatory Flexibility Act.

We prepared a regulatory evaluation of the estimated costs to comply with this proposed AD and placed it in the AD docket. See the ADDRESSES section for a location to examine the regulatory evaluation.

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 39-14499 (71 FR 10605, March 2, 2006) and adding the following new AD:

Boeing: Docket No. FAA-2009-0655; Directorate Identifier 2008-NM-192-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by September 8, 2009.

Affected ADs

(b) This AD supersedes AD 2006-05-02.

Applicability

(c) This AD applies to all Boeing Model 747-200F, 747-200C, 747-400, 747-400D, and 747-400F series airplanes; certificated in any category.

Subject

(d) Air Transport Association (ATA) of America Code 53: Fuselage.

Unsafe Condition

(e) This AD results from fatigue tests and analysis that identified additional areas of the fuselage where fatigue cracks can occur. We are issuing this AD to prevent loss of the structural integrity of the fuselage, which could result in rapid depressurization 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 2006-05-02 With Reduced Compliance Times for Group 8 Airplanes

Inspections

(g) Do initial and repetitive inspections for fuselage cracks using applicable internal and external detailed inspection methods, and repair all cracks, by doing all the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004; or Revision 1, dated September 25, 2008; except as required by paragraph (h) or provided by paragraph (l) of this AD. After the effective date of this AD, Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008, must be used. Do the initial and repetitive inspections at the applicable times specified in paragraph (g)(1) or (g)(2) of this AD, except as required by paragraph (j) of this AD. Repair any crack before further flight after detection.

(1) For Groups 1 through 7, 9, and 10 identified in Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008: Do the initial and repetitive inspections at the times specified in paragraph 1.E. of Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004, except as required by paragraph (i) of this AD.

(2) For Group 8 airplanes identified in Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008: Do the initial and repetitive inspections at the applicable time specified in paragraph 1.E. of Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008, except as required by paragraph (k) of this AD.

Exceptions to Service Bulletin Procedures

(h) If any crack is found during any inspection required by this AD, and Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004, or Revision 1, dated September 25, 2008, 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 (m) of this AD.

(i) Where Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004, or Revision 1, dated September 25, 2008, specifies a compliance time after the date on the original issue of the service bulletin, this AD requires compliance within the specified compliance time after April 6, 2006 (the effective date of AD 2006-05-02).

New Requirements of This AD

Actions for Additional Areas

(j) For the additional inspection areas of Groups 1 through 7, 9, and 10 airplanes, identified in Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008: Do initial and repetitive inspections for cracking of the inspection areas, and, as applicable, repair cracking, by doing all the actions specified in the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008; except as required by paragraph (h) of this AD. Do the initial and repetitive inspections at the times specified in paragraph 1.E. of Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008, except as required by paragraph (k) of this AD. Repair all cracking before further flight.

(k) Where Boeing Alert Service Bulletin 747-53A2500, Revision 1, dated September 25, 2008, specifies a compliance time after the date on Revision 1 of the service bulletin, this AD requires compliance within the specified compliance time after the effective date of this AD.

(l) For Group 8 airplanes, inspection of Areas 2 and 5 identified in Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004 as required by paragraph (g) of this AD is no longer required.

Alternative Methods of Compliance (AMOCs)

(m)(1) The Manager, Seattle ACO, FAA, has the authority to approve AMOCs for this AD, if requested using the procedures found in 14 CFR 39.19. Send information to ATTN: Ivan Li, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98057-3356; telephone [phone]; fax [phone]. Or, e-mail information to [e-mail].

(2) To request a different method of compliance or a different compliance time for this AD, follow the procedures in 14 CFR 39.19. Before using any approved AMOC on any airplane to which the AMOC applies, notify your principal maintenance inspector (PMI) or principal avionics inspector (PAI), as appropriate, or lacking a principal inspector, your local Flight Standards District Office. The AMOC approval letter must specifically reference this AD.

(3) AMOCS approved previously in accordance with AD 2006-05-02, are approved as alternative methods of compliance with the corresponding requirements of this AD.

(4) Accomplishment of the inspections specified in this AD is considered an AMOC for the applicable requirements of paragraphs (c) and (d) of AD 2004-07-22 R1, amendment 39-15326, under the conditions specified in paragraphs (m)(4)(i) and (m)(4)(ii) of this AD.

(i) The inspections specified in this AD must be done within the compliance times specified in AD 2004-07-22 R1. The initial inspection specified in this AD must be done at the times specified in paragraph (d) of AD 2004-07-22 R1, and the inspections specified in this AD must be repeated within the intervals specified in paragraph (g) of this AD.

(ii) The AMOC applies only to the areas of Supplemental Structural Inspection Document for Model 747 Airplanes, Document D6-35022, Revision G, dated December 2000, that are specified in Boeing Alert Service Bulletin 747-53A2500, dated December 21, 2004.

(5) An AMOC that provides an acceptable level of safety may be used for any repair required by this AD, if it is approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization who 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.

Issued in Renton, Washington, on July 15, 2009.

Stephen P. Boyd,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.