05-1584. Airworthiness Directives; Boeing Model 747-200B, -200C, -200F, 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 series airplanes. This proposed AD would require repetitive detailed inspections for cracks in the crease beam and adjacent structure of the fuselage, and related investigative and corrective actions if necessary. This proposed AD is prompted by fatigue cracks found in the crease beam during a follow-on inspection of a previously installed modification. We are proposing this AD to find and fix fatigue cracking of the fuselage frame, which could result in reduced structural integrity of the frame and consequent rapid decompression of the airplane.

DATES:

We must receive comments on this proposed AD by March 14, 2005.

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.
• By 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.

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

FOR FURTHER INFORMATION CONTACT:

Technical Information: 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:

Docket Management System (DMS)

The FAA has implemented new procedures for maintaining AD dockets electronically. As of May 17, 2004, new AD actions are posted on DMS and assigned a docket number. We track each action and assign a corresponding directorate identifier. The DMS AD docket number is in the form “Docket No. FAA-2005-99999.” The Transport Airplane Directorate identifier is in the form “Directorate Identifier 2005-NM-999-AD.” Each DMS AD docket also lists the directorate identifier (“Old Docket Number”) as a cross-reference for searching purposes.

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 under ADDRESSES. Include “Docket No. FAA-2005-20136; Directorate Identifier 2004-NM-185-AD” in the subject line 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 submitted 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 can review DOT's complete Privacy Act Statement in the Federal Register published on April 11, 2000 (65 FR 19477-78), or you can visit http://dms.dot.gov.

We are reviewing the writing style we currently use in regulatory documents. We are interested in your comments on whether the style of this document is clear, and your suggestions to improve the clarity of our communications that affect you. You can get more information about plain language at http://www.faa.gov/​language and http://www.plainlanguage.gov.

Examining the Docket

You can 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 DMS receives them.

Discussion

We have received a report indicating that cracking was found on a 747-200 series airplane during a follow-on inspection of a previously installed modification of the crease beam of the fuselage. The cracking is attributed to fatigue due to cabin pressurization cyclic loading. This condition, if not corrected, could result in reduced structural integrity of the fuselage frame and consequent rapid decompression of the airplane.

The crease beam of the fuselage on certain Model 747-200B, -200C, -200F, and -400F series airplanes is identical to that on the affected Model 747-200 series airplane. Therefore, all of these models may be subject to the same unsafe condition.

Other Related Rulemaking

On October 26, 1989, we issued AD 89-08-03 R1, amendment 39-6389 (54 FR 46367, November 3, 1989), applicable to certain Boeing Model 747 series airplanes, (line numbers 66 through 603 inclusive). That AD requires inspections for cracks of the fuselage between body station (BS) 940 and BS 1000, the body crown crease beam, and the intercostal structure; and repair if necessary. The newly reported fatigue cracking of the crease beam and adjacent structure of the fuselage that prompted this new proposed AD occurred at approximately 10,000 flight cycles after the airplane had been modified per the repair procedures specified in Boeing Service Bulletin 747-53-2297, Revision 1, dated January 26, 1989 (referenced in AD 89-08-03 R1 for accomplishing the specified actions).

Although AD 89-08-03 R1 contains adequate post-modification/repair inspections, there are no such inspections required for airplanes with line numbers 604 and subsequent. This proposed AD would require inspections for airplanes that are not included in the applicability specified in AD 89-08-03 R1.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2504, dated August 19, 2004. The service bulletin describes procedures for repetitive detailed inspections for cracks in the crease beam and adjacent structure of the fuselage, and related investigative and corrective actions if necessary. The related investigative action is a high frequency eddy current inspection for additional cracking in adjacent skin panel fastener locations. The corrective action involves repairing any cracks found during any inspection. 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. Therefore, we are proposing this AD, which would require accomplishing the actions specified in the service information described previously, except as discussed under “Differences Between Proposed AD and Service Bulletin.”

Differences Between Proposed AD and Service Bulletin

For certain airplanes, the service bulletin recommends reporting any discrepancies to the manufacturer; however, this proposed AD does not include that requirement.

Although the service bulletin specifies that operators may contact the manufacturer for disposition of certain repair conditions, this proposed AD would require operators to repair those conditions 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 Delegation Option Authorization (DOA) Organization whom we have authorized to make those findings.

Costs of Compliance

There are about 163 airplanes of the affected design in the worldwide fleet. This proposed AD would affect about 30 airplanes of U.S. registry. The proposed inspection would take about 8 work hours per airplane, at an average labor rate of $65 per work hour. Based on these figures, the estimated cost of the proposed inspection for U.S. operators is $15,600, or $520 per airplane, per inspection cycle.

Authority for This Rulemaking

The FAA's authority to issue rules regarding aviation safety is found in Title 49 of the United States Code. 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.

This rulemaking is promulgated 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 proposed AD.

Regulatory Findings

We have determined that this proposed AD will not have federalism implications under Executive Order 13132. This proposed AD will 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. 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 FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-20136; Directorate Identifier 200--NM-185-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by March 14, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-200B, -200C, -200F, and -400F series airplanes, line numbers 604 and subsequent, certificated in any category; as listed in Boeing Alert Service Bulletin 747-53A2504, dated August 19, 2004.

Unsafe Condition

(d) This AD was prompted by fatigue cracks found in the crease beam during a follow-on inspection of a previously installed modification. We are issuing this AD to find and fix fatigue cracking of the fuselage frame, which could result in reduced structural integrity of the frame and consequent rapid decompression 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.

Repetitive Inspections

(f) Accomplish a detailed inspection for cracks in the crease beam and adjacent structure of the fuselage by doing all the applicable actions in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2504, dated August 19, 2004; at the applicable time specified in paragraph (f)(1) or (f)(2) of this AD. Repeat the inspection thereafter at intervals not to exceed 6,000 flight cycles.

(1) For Groups 1 and 2 airplanes as identified in the service bulletin: Before the accumulation of 10,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever is later.

(2) For Groups 3 and 4 airplanes as identified in the service bulletin: Before the accumulation of 14,000 total flight cycles, or within 1,500 flight cycles after the effective date of this AD, whichever is later.

Related Investigative and Corrective Actions

(g) If any crack is found during any inspection required by paragraph (f) of this AD: Before further flight, repair the cracking in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2504, dated August 19, 2004. If cracking of the crease beam or outer tee chord attachment is found: Before further flight, do a high frequency eddy current inspection for additional cracking, and repair any cracking found, in accordance with the service bulletin. Where the service bulletin specifies contacting the manufacturer for disposition of certain repair conditions, repair before further flight in accordance with a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or by an Authorized Representative for the Boeing Delegation Option Authorization (DOA) 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.

No Reporting Required

(h) For certain airplanes, the service bulletin referenced in this AD recommends reporting any discrepancies to the manufacturer, but this AD does not include that requirement.

Alternative Methods of Compliance (AMOCs)

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

(2) An AMOC that provides an acceptable level of safety may be used for a repair required by this AD, if it is approved by an Authorized Representative for the Boeing DOA Organization who has been authorized by the Manager, Seattle ACO, to make such findings.

Issued in Renton, Washington, on January 18, 2005.

Ali Bahrami,

Manager, Transport Airplane Directorate, Aircraft Certification Service.