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Proposed Rule

Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes

Document Details

Information about this document as published in the Federal Register.

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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 747-400, 747-400D, and 747-400F series airplanes. This proposed AD would require repetitive detailed inspections for damage (degraded finish; missing, lifted, peeling, or blistering paint; or signs of corrosion) of the interior skin in the forward and aft cargo compartments, and corrective actions if necessary. This proposed AD is prompted by reports of skin corrosion on four Boeing Model 747 series airplanes that were delivered between 1995 and 1999. We are proposing this AD to detect and correct corrosion, which can penetrate the thickness of the skin and cause cracking, and result in rapid decompression of the airplane.

DATES:

We must receive comments on this proposed AD by October 31, 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: (202) 493-2251.
  • 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.

You can examine the contents of this AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility, U.S. Department of Transportation, 400 Seventh Street, SW., room PL-401, on the plaza level of the Nassif Building, Washington, DC. This docket number is FAA-2005-22437; the directorate identifier for this docket is 2005-NM-082-AD.

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FOR FURTHER INFORMATION CONTACT:

Nicholas Kusz, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6432; fax (425) 917-6590.

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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 under ADDRESSES. Include “Docket No. FAA-2005-22437; Directorate Identifier 2005-NM-082-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.

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 (800) 647-5227) 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 (DMS) receives them.

Discussion

In April 1988, a high-cycle transport category airplane (specifically, a Boeing Model 737) was involved in an accident in which the airplane suffered major structural damage during flight. Investigation of this accident revealed that the airplane had numerous fatigue cracks and a great deal of corrosion. Subsequent inspections conducted by the operator on other high-cycle transport category airplanes in its fleet revealed that other airplanes had extensive fatigue cracking and corrosion.

Prompted by the data gained from this accident, we sponsored a conference on aging airplanes in June 1988, which was attended by representatives from the aviation industry and airworthiness authorities from around the world. It became obvious that, because of the tremendous increase in air travel, the relatively slow pace of new airplane production, and the apparent economic feasibility of operating older technology airplanes rather than retiring them, increased attention needed to be focused on the aging airplane fleet and maintaining its continued operational safety.

The Air Transport Association (ATA) of America and the Aerospace Industries Association (AIA) of America agreed to undertake the task of identifying and implementing procedures to ensure the continued structural airworthiness of aging transport category airplanes. An Airworthiness Assurance Working Group (AAWG) was established in August 1988, with members Start Printed Page 54485representing aircraft manufacturers, operators, regulatory authorities, and other aviation industry representatives worldwide. The objective of the AAWG was to sponsor “Task Groups” to:

1. Select service bulletins, applicable to each airplane model in the transport fleet, to be recommended for mandatory modification of aging airplanes;

2. Develop corrosion-directed inspections and prevention programs;

3. Review the adequacy of each operator's structural maintenance program;

4. Review and update the Supplemental Inspection Documents (SID); and

5. Assess repair quality.

The Working Group assigned to review Boeing Model 747 series airplanes completed its work on Item (2) in 1989 and developed a baseline program for controlling corrosion problems that may jeopardize the continued airworthiness of the Boeing Model 747 fleet. This program is contained in Boeing Document Number D6-36022, “Aging Airplane Corrosion Prevention and Control Program—Model 747,” Revision A, dated July 28, 1989. On November 5, 1990, we issued AD 90-25-05, amendment 39-6790 (55 FR 49268, November 27, 1990). That AD mandates Boeing Document Number D6-36022, and requires that operators of Boeing Model 747 series airplanes implement a Corrosion Prevention and Control Program (CPCP).

Since we issued AD 90-25-05, two operators found skin corrosion on four Boeing Model 747 series airplanes that were delivered between 1995 and 1999. The corrosion happened when primer peeled off in some areas of the skin and left the aluminum unprotected against moisture and corrosive elements. The operators repaired three of the airplanes by trimming-out the damaged skin, and one of the airplanes by blending to remove the damage. One other operator reported finding peeling primer, but no corrosion, on the interior skin surface of one airplane, below the cargo bay. The manufacturer investigated these incidents and found that the manufacturing process for the skins resulted in inadequate adhesion of the primer to the skin. The interior surface of the skin below the cargo bay is susceptible to corrosion because of the presence of moisture. If areas of corrosion are not repaired, the corrosion can penetrate the thickness of the skin and cause cracking. This condition, if not corrected, could result in rapid decompression of the airplane.

Relevant Service Information

We have reviewed Boeing Alert Service Bulletin 747-53A2505, dated March 17, 2005. The service bulletin describes procedures for doing a detailed inspection for damage of the interior skin in the forward and aft cargo compartments. Damage includes a degraded finish; missing, lifted, peeling, or blistering paint; or signs of corrosion. If any damage is found, the service bulletin describes procedures for corrective actions. The corrective actions are restoring the finish if only damage to the finish is found; or repairing the affected area and restoring the protective finish if the finish is damaged and any corrosion is found. If any corrosion damage exceeds limits in the structural repair manual (SRM), the service bulletin states that operators should contact Boeing for repair instructions. If no damage or corrosion is found, the service bulletin states that no further action is necessary until the next inspection. The service bulletin recommends repeating the detailed inspection every four years until the initial inspection threshold for the applicable CPCP task in Boeing Document Number D6-36022 is reached. The service bulletin also requests that operators send reports of the inspection program and details of any corrosion damage and peeling primer to the manufacturer. Accomplishing the actions specified in the service bulletin 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 the Proposed AD and the Service Bulletin.”

Differences Between the Proposed AD and the Service Bulletin

Although the service bulletin referenced in this proposed AD specifies to submit to the manufacturer a report of the inspection program and details of any corrosion damage and peeling paint primer, this proposed AD does not include those actions.

The service bulletin specifies that you may contact the manufacturer for instructions on how to repair corrosion damage that exceeds limits in the SRM, but this proposed AD would require you to repair 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 260 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

ActionWork hoursAverage labor rate per hourPartsCost per airplaneNumber of U.S.-registered airplanesFleet cost
Detailed inspection, per inspection cycle10$65N/A$650, per inspection cycle36$23,400, 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 Start Printed Page 54486because 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. See the ADDRESSES section for a location to examine the regulatory evaluation.

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List of Subjects in 14 CFR Part 39

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The Proposed Amendment

Accordingly, under the authority delegated to me by the Administrator, the FAA proposes to amend 14 CFR part 39 as follows:

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PART 39—AIRWORTHINESS DIRECTIVES

1. The authority citation for part 39 continues to read as follows:

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Authority: 49 U.S.C. 106(g), 40113, 44701.

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[Amended]

2. The FAA amends § 39.13 by adding the following new airworthiness directive (AD):

Boeing: Docket No. FAA-2005-22437; Directorate Identifier 2005-NM-082-AD.

Comments Due Date

(a) The Federal Aviation Administration (FAA) must receive comments on this AD action by October 31, 2005.

Affected ADs

(b) None.

Applicability

(c) This AD applies to Boeing Model 747-400, 747-400D, and 747-400F series airplanes, certificated in any category; as identified in Boeing Alert Service Bulletin 747-53A2505, dated March 17, 2005.

Unsafe Condition

(d) This AD was prompted by reports of skin corrosion on four Boeing Model 747 series airplanes that were delivered between 1995 and 1999. We are issuing this AD to detect and correct corrosion, which can penetrate the thickness of the skin and cause cracking, and result in 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 and Corrective Actions

(f) Within 12 months after the effective date of this AD, do a detailed inspection for damage (degraded finish; missing, lifted, peeling, or blistering paint; or signs of corrosion) of the interior skin in the forward and aft cargo compartments. Do any applicable corrective actions before further flight. Except as required by paragraphs (g) and (h) of this AD, do all actions in accordance with the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2505, dated March 17, 2005. Repeat the inspection thereafter at intervals not to exceed 48 months until accomplishing task number C53-125-01 of Boeing Document Number D6-36022, “Aging Airplane Corrosion Prevention and Control Program—Model 747,” Revision A, dated July 28, 1989, or until accomplishing tasks S53-520 and S53-550 of Boeing Document Number D621U400-MRB, “B747-400 Maintenance Review Board Report,” Revision E, dated May 2003.

Note 1:

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.”

Damage that Exceeds Structural Repair Manual Limits

(g) If any corrosion damage that exceeds the limits specified in the structural repair manual is found during any action required by this AD, and Boeing Alert Service Bulletin 747-53A2505, dated March 17, 2005 specifies to contact Boeing for repair instructions: Before further flight, repair the damage using a method approved in accordance with paragraph (i) of this AD.

No Reporting Requirement

(h) Although Boeing Alert Service Bulletin 747-53A2505, dated March 17, 2005, specifies to submit to the manufacturer a report of the inspection program and details of any corrosion damage and peeling paint primer, this AD does not include those actions.

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) 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.

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Issued in Renton, Washington, on September 8, 2005.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.

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[FR Doc. 05-18319 Filed 9-14-05; 8:45 am]

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