Federal Aviation Administration, DOT.
Notice of proposed rulemaking (NPRM).
This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 747-100, -200B, and -200F series airplanes. This proposal would require initial and repetitive inspections to find discrepancies in the upper and lower skins of the fuselage lap joints, and repair if necessary. This action is necessary to find and fix such discrepancies, which could result in sudden fracture and failure of a lap joint and rapid in-flight decompression of the airplane fuselage. This action is intended to address the identified unsafe condition.
Comments must be received by August 18, 2003.
Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-Start Printed Page 39484149-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9 a.m. and 3 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to (425) 227-1232. Comments may also be sent via the Internet using the following address: firstname.lastname@example.org. Comments sent via fax or the Internet must contain “Docket No. 2002-NM-149-AD” in the subject line and need not be submitted in triplicate. Comments sent via the Internet as attached electronic files must be formatted in Microsoft Word 97 or 2000 or ASCII text.
The service information referenced in this AD may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington.Start Further Info
FOR FURTHER INFORMATION CONTACT:
Rick Kawaguchi, Aerospace Engineer, Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 917-6434; fax (425) 917-6590.End Further Info End Preamble Start Supplemental Information
Interested persons are invited to participate in the making of the proposed rule by submitting such written data, views, or arguments as they may desire. Communications shall identify the Rules Docket number and be submitted in triplicate to the address specified above. All communications received on or before the closing date for comments, specified above, will be considered before taking action on the proposed rule. The proposals contained in this action may be changed in light of the comments received. Submit comments using the following format:
- Organize comments issue-by-issue. For example, discuss a request to change the compliance time and a request to change the service bulletin reference as two separate issues.
- For each issue, state what specific change to the proposed AD is being requested.
- Include justification (e.g., reasons or data) for each request.
Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the proposed rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report summarizing each FAA-public contact concerned with the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this action must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2002-NM-149-AD.” The postcard will be date stamped and returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request to the FAA, Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2002-NM-149-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.
The FAA has received a report indicating rapid in-flight decompression of a Boeing Model 737 series airplane. Investigation revealed that the skin above the forward entry door was separated at the stringer S-4R lap joint, with a 28-inch tear running along the lap joint. The skin was bent back at the upper edge of the stringer at S-5R and formed a rectangular opening that progressed from body station (BS) 328 to BS 300. Further investigation revealed that numerous scratches on the skin of the lap joint had initiated fatigue cracks and subsequent tearing of the skin. We also have received reports of similar damage (corrosion and fatigue cracking) to certain lap joints on other Model 737 series airplanes. These discrepancies have been attributed to the manufacturing process, which includes a cold-bonded adhesive of the lap joint configuration. Such conditions, if not corrected, could result in sudden fracture and failure of a lap joint and rapid in-flight decompression of the airplane fuselage.
The subject area on certain Model 747-100, -200B, and -200F series airplanes is manufactured using a process similar to that used on the affected Model 737 series airplanes. Therefore, those Model 747-100, -200B, and -200F series airplanes may be subject to the same unsafe condition revealed on the Model 737 series airplanes.
This AD is related to AD 2000-17-04, amendment 39-11878, (65 FR 51750, August 25, 2000), applicable to certain Boeing Model 737-100, -200, and -200C series airplanes. That AD requires repetitive inspections to detect discrepancies in the upper and lower skins of the fuselage lap joint, and repair if necessary.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin 747-53A2463, including Appendices A, B, and C, and the Evaluation Form, dated March 7, 2002, which describes procedures for repetitive medium and low frequency eddy current inspections for discrepancies (cracking and/or corrosion), and repair of any discrepancies found. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to exist or develop on other products of this same type design, the proposed AD would require accomplishment of the actions specified in the service bulletin described previously, except as discussed below.
Difference Between Alert Service Bulletin and This Proposed AD
Although the alert service bulletin specifies that the manufacturer may be contacted for disposition of certain repair conditions or inspection procedures, this proposed AD requires the repair and inspection procedures be accomplished in accordance with a method approved by the FAA, or in accordance with data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative who has been authorized by the FAA to make such findings.
Changes to 14 CFR Part 39/Effect on the Proposed AD
On July 10, 2002, the FAA issued a new version of 14 CFR part 39 (67 FR 47997, July 22, 2002), which governs the FAA's airworthiness directives system. The regulation now includes material that relates to altered products, special flight permits, and alternative methods of compliance. Because we have now included this material in part 39, we no longer need to include it in each individual AD; however, this AD identifies the office authorized to approve alternative methods of compliance.
There are approximately 86 airplanes of the affected design in the worldwide fleet. The FAA estimates that 55 Start Printed Page 39485airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 5,334 work hours per airplane to accomplish the proposed inspections, and that the average labor rate is $60 per work hour. Based on these figures, the cost impact of the proposed AD on U.S. operators is estimated to be $17,602,200, or $320,040 per airplane.
The cost impact figure discussed above is based on assumptions that no operator has yet accomplished any of the proposed requirements of this AD action, and that no operator would accomplish those actions in the future if this proposed AD were not adopted. The cost impact figures discussed in AD rulemaking actions represent only the time necessary to perform the specific actions actually required by the AD. These figures typically do not include incidental costs, such as planning time, or time necessitated by other administrative actions.
The regulations proposed herein 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. Therefore, it is determined that this proposal would not have federalism implications under Executive Order 13132.
For the reasons discussed above, I certify that this 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) if promulgated, 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. A copy of the draft regulatory evaluation prepared for this action is contained in the Rules Docket. A copy of it may be obtained by contacting the Rules Docket at the location provided under the caption ADDRESSES.Start List of Subjects
List of Subjects in 14 CFR Part 39
- Air transportation
- Aviation safety
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration proposes to amend part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:Start Part
PART 39—AIRWORTHINESS DIRECTIVES
1. The authority citation for part 39 continues to read as follows:
2. Section 39.13 is amended by adding the following new airworthiness directive:
Boeing: Docket 2002-NM-149-AD.
Applicability: Model 747-100, -200B, and -200F series airplanes, as listed in Boeing Alert Service Bulletin 747-53A2463, dated March 7, 2002; certificated in any category.
Compliance: Required as indicated, unless accomplished previously.
To find and fix discrepancies in the upper and lower skins of the fuselage lap joints, which could result in sudden fracture and failure of a lap joint and rapid in-flight decompression of the airplane fuselage, accomplish the following:
Initial and Repetitive Inspections
(a) Do the applicable (initial and repetitive) inspections as specified in Figures 2 through 8, as applicable, of the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, including Appendices A, B, and C, dated March 7, 2002, to find discrepancies (cracking and corrosion) in the upper and lower skins of the fuselage lap joints. Do the inspections at the applicable times specified in Figure 1 of the Accomplishment Instructions of the alert service bulletin, in accordance with the alert service bulletin; except that where Figure 1 specifies a compliance time of “after the release date of this service bulletin,” this AD requires a compliance time of “after the effective date of this AD.” Where Figure 1 specifies a compliance time of “flight cycles” this AD requires a compliance time of “total flight cycles.”
(b) Where Boeing Alert Service Bulletin 747-53A2463, including Appendices A, B, and C, dated March 7, 2002, specifies that the manufacturer may be contacted for certain inspection procedures, inspect per a method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA; or per data meeting the type certification basis of the airplane approved by a Boeing Company Designated Engineering Representative (DER) who has been authorized by the Manager, Seattle ACO, to make such findings.
Adjustments to Compliance Time: Cabin Differential Pressure
(c) For the purposes of calculating the compliance threshold and repetitive interval for the inspections required by paragraph (a) of this AD: Flight cycles in which cabin differential pressure is at 2.0 pounds per square inch (psi) or less need not be counted when determining the number of flight cycles that have occurred on the airplane, provided that flight cycles with momentary spikes in cabin differential pressure above 2.0 psi are included as full pressure flight cycles. For this provision to apply, all cabin pressure records must be maintained for each airplane. No fleet-averaging of cabin pressure is allowed.
(d) Before further flight, repair any discrepancy (cracking or corrosion) found during any inspection required by paragraph (a) of this AD, per the Accomplishment Instructions of Boeing Alert Service Bulletin 747-53A2463, including Appendices A, B, and C, dated March 7, 2002. If any discrepancy is found and the alert service bulletin specifies that the manufacturer may be contacted for disposition of certain repairs, before further flight, repair per a method approved by the Manager, Seattle ACO; or per data meeting the type certification basis of the airplane approved by a Boeing Company DER who has been authorized by the Manager, Seattle ACO, to make such findings.
Alternative Methods of Compliance
(e) In accordance with 14 CFR 39.19, the Manager, Seattle ACO, is authorized to approve alternative methods of compliance for this AD.
Issued in Renton, Washington, on June 26, 2003.
Michael J. Kaszycki,
Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.
[FR Doc. 03-16694 Filed 7-1-03; 8:45 am]
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