05-23654. Airworthiness Directives; Boeing Model 747-200C, -200F, -400, -400D, and -400F Series Airplanes

AGENCY:

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

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

The FAA proposes to adopt a new airworthiness directive (AD) for certain Boeing Model 747-200C, -200F, -400, -400D, and -400F series airplanes. This proposed AD would require repetitive inspections for cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46; and related investigative and corrective actions, if necessary. This proposed AD results from fatigue tests and an analysis that identified areas of the fuselage lap joints where fatigue cracks can occur. We are proposing this AD to detect and correct fatigue cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46, which could adversely affect the structural integrity of the airplane.

DATES:

We must receive comments on this proposed AD by January 20, 2006.

ADDRESSES:

Use one of the following addresses to submit comments on this proposed AD.

• DOT Docket Web site: Go to http://dms.dot.gov and follow the instructions for sending your comments electronically.
• Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your comments electronically.
• Mail: Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., Nassif Building, room PL-401, Washington, DC 20590.
• Fax: [phone].
• Hand Delivery: Room PL-401 on the plaza level of the Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays.

Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-2207, for the service information identified in this proposed AD.

FOR FURTHER INFORMATION CONTACT:

Nick Kusz, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

Comments Invited

We invite you to submit any relevant written data, views, or arguments regarding this proposed AD. Send your comments to an address listed in the ADDRESSES section. Include the docket number “FAA-2005-23196; Directorate Identifier 2005-NM-187-AD” at the beginning of your comments. We specifically invite comments on the overall regulatory, economic, environmental, and energy aspects of the proposed AD. We will consider all comments received by the closing date and may amend the proposed AD in light of those comments.

We will post all comments we receive, without change, to http://dms.dot.gov,, including any personal information you provide. We will also post a report summarizing each substantive verbal contact with FAA personnel concerning this proposed AD. Using the search function of that Web site, anyone can find and read the comments in any of our dockets, including the name of the individual who sent the comment (or signed the comment on behalf of an association, business, labor union, etc.). You may review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you may visit http://dms.dot.gov.

Examining the Docket

You may examine the AD docket on the Internet at http://dms.dot.gov,, or in person at the Docket Management Facility office between 9 a.m. and 5 p.m., Monday through Friday, except Federal holidays. The Docket Management Facility office (telephone [phone]) is located on the plaza level of the Nassif Building at the DOT street address stated in the ADDRESSES section. Comments will be available in the AD docket shortly after the Docket Management System receives them.

Discussion

We have received a report indicating that the airplane manufacturer has completed extended pressure fatigue tests on 747-100SR and 747-400 fuselage test articles. Analysis of these test results have identified areas of the fuselage lap joints where fatigue cracks can occur on Boeing Model 747-200C, -200F, -400, -400D, and -400F series airplanes. Fatigue cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46, if not detected and corrected in a timely manner, could adversely affect the structural integrity of the airplane.

Other Relevant Rulemaking

We have previously issued AD 94-12-04, amendment 39-8932 (59 FR 30277, June 13, 1994), applicable to certain Boeing Model 747-100, -200, -300, 747SP, and 747SR series airplanes. That AD requires repetitive inspections to detect cracking in the upper row of certain fuselage skin lap joints, and repair, if necessary. This proposed AD addresses a similar unsafe condition on a different group of airplanes and would not affect the current requirements of AD 94-12-04.

We also previously issued AD 2004-07-22, amendment 39-13566 (69 FR 18250, April 7, 2004), applicable to all Boeing Model 747 series airplanes. (A final rule correction was published in the Federal Register on May 3, 2004 (69 FR 24063)). That AD requires that the FAA-approved maintenance inspection program be revised to include inspections that will give no less than the required damage tolerance rating for each structural significant item, and repair or cracked structure. The proposed AD would not affect the current requirements of that AD.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2499, dated August 11, 2005. The service bulletin describes procedures for repetitive external surface high frequency eddy current (HFEC), external low frequency eddy current (LFEC), and internal LFEC inspections, as applicable, for cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46; and any applicable related investigative and corrective actions, if necessary. The related investigative actions involve doing open-hole HFEC inspections of the fastener holes to find the total crack length. The corrective actions involve repairing any cracked lap joint and doing open-hole HFEC inspection of the skin at all existing fastener locations common to the repair. The intervals for doing the repetitive inspections are 1,500, 2,400, or 3,000 flight cycles, depending on the airplane configuration. Accomplishing the actions specified in the service information is intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

We have evaluated all pertinent information and identified an unsafe condition that is likely to exist or develop on other airplanes of this same type design. For this reason, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Difference Between the Proposed AD and Service Bulletin.”

Difference Between Proposed Rule and Service Bulletin

The service bulletin 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:

• Using a method that we approve; or
• Using data that meet the certification basis of the airplane, and that have been approved by an Authorized Representative for the Boeing Commercial Airplanes Delegation Option Authorization Organization whom we have authorized to make those findings.

Costs of Compliance

There are about 796 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 153 airplanes of U.S. registry. The proposed inspections would take about 534 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed AD for U.S. operators is $5,310,630, or $34,710 per airplane, 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
• 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 Federal Aviation Administration (FAA) amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-23196; Directorate Identifier 2005-NM-187-AD.

Comments Due Date

(a) The FAA must receive comments on this AD action by January 20, 2006.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-200C, -200F, -400, -400D, and -400F series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2499, dated August 11, 2005.

Unsafe Condition

(d) This AD results from fatigue tests and an analysis that identified areas of the fuselage lap joints where fatigue cracks can occur. We are issuing this AD to detect and correct fatigue cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46, which could adversely affect the structural integrity of the airplane.

Compliance

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

Initial Inspections and Related Investigative and Corrective Actions

(f) At the applicable time specified in Table 1 of this AD: Do an external surface high frequency eddy current (HFEC), external low frequency eddy current (LFEC), and internal LFEC inspections, as applicable, for cracks in the overlapping (upper) skin, upper fastener row of the lap joints of the fuselage skin in sections 41, 42, and 46, and any applicable related investigative and corrective actions by doing all of the actions in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2499, dated August 11, 2005, except as provided by paragraph (h) of this AD. Do any applicable related investigative and corrective actions before further flight.

Table 1.—Initial Compliance Time

For airplanes on which Structural Significant Items (SSIs) F-25G, F-25H, and F-25I—	Inspect—
(1) Have not been inspected in accordance with paragraph (d) of AD 2004-07-22, amendment 39-13566, using the HFEC method	Before the accumulation of 22,000 total flight cycles, or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.
(2) Have been inspected in accordance with paragraph (d) of AD 2004-07-22, amendment 39-13566, using the HFEC method	Within 3,000 flight cycles after the most recent Supplemental Structural Inspection Document (SSID) inspection of each applicable structural significant item (as given in Boeing Document D6-35022, “SSID for Model 747 Airplanes,” Revision G, dated December 2000), or within 1,000 flight cycles after the effective date of this AD, whichever occurs later.

Repetitive Inspections

(g) Repeat the applicable inspections required by paragraph (f) of this AD thereafter at intervals not to exceed those specified in paragraph 1.E., “Compliance” (including the note) of Boeing Alert Service Bulletin 747-53A2499, dated August 11, 2005.

Exception to Service Bulletin Instructions

(h) Where the service bulletin 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 (i) of this AD.

Alternative Methods of Compliance (AMOCs)

(i)(1) The Manager, Seattle Aircraft Certification Office (ACO), FAA, has the authority to approve AMOCs for this AD, if requested in accordance with the procedures found in 14 CFR 39.19.

(2) Before using any AMOC approved in accordance with § 39.19 on any airplane to which the AMOC applies, notify the appropriate principal inspector in the FAA Flight Standards 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 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 November 17, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.