00-21614. Airworthiness Directives; Boeing Model 737-200 and -300 Series Airplanes Equipped with a Main Deck Cargo Door Installed in Accordance with Supplemental Type Certificate (STC) SA2969SO

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This document publishes in the Federal Register an amendment adopting airworthiness directive (AD) 2000-17-51 that was sent previously to all known U.S. owners and operators of certain Boeing Model 737-200 and -300 series airplanes by individual notices. This AD supersedes an existing AD to require a one-time inspection to detect cracks of the lower frames and reinforcing angles of the main deck cargo door where the door latch fittings attach between certain fuselage stations and water lines, and replacement of any cracked part with a new part having the same part number. This action is prompted by reports that, during the inspections required by the existing AD, cracks were found in the reinforcing angles of the main deck cargo door frame. The actions specified by this AD are intended to detect and correct cracking of the lower portion of the main deck cargo door frames, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane.

DATES:

Effective August 30, 2000, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-17-51, issued on August 14, 2000, which contained the requirements of this amendment.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of August 30, 2000.

Comments for inclusion in the Rules Docket must be received on or before October 24, 2000.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-277-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056. Comments may be inspected at this location between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal holidays. Comments may be submitted via fax to [phone]. Comments may also be sent via the Internet using the following address: [e-mail]. Comments sent via fax or the Internet must contain “Docket No. 2000-NM-277-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 for Windows or ASCII text.

The applicable service information may be obtained from Pemco World Air Services, 100 Pemco Drive, Dothan, AL 36303. This information may be examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30349; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Rany Azzi, Aerospace Engineer, Airframe and Propulsion Branch, ACE-117A, FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia 30337-2748, telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

On July 13, 2000, the FAA issued AD 2000-13-51, amendment 39-11826 (65 FR 44977, July 20, 2000), applicable to certain Boeing Model 737-200 and -300 series airplanes. That AD requires repetitive special detailed inspections to detect cracking of the main deck cargo door frames, their existing reinforcing angles (where applicable), and the attach holes of the latch fittings between frame station (FS) 361.87 and FS 498.12, and between water line (WL) 202.35 and WL 213.00, in the area where the main deck cargo door latch fittings attach to the frames; and corrective actions, if necessary. That action was prompted by a report indicating that three of the subject airplanes had multiple cracks in the lower portion of the main deck cargo door frames and, in some cases, the reinforcing angles. The actions required by that AD are intended to detect and correct cracking of the lower portion of the main deck cargo door frames, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane.

Actions Since Issuance of Previous Rule

Since the issuance of AD 2000-13-51, the FAA has received reports that, during the special detailed inspections (i.e., borescope) required by that AD, cracks were found in the reinforcing angles of the main deck cargo door frame. Subsequent disassembly of the affected structure revealed substantial cracking that was hidden by the layered structure and not detected by the special detailed inspections. These findings are a clear indication of multiple element damage (MED). MED is a source of widespread fatigue damage (WFD), which is characterized by the simultaneous presence of cracks in multiple structural details that are of sufficient size and density, whereby the structure will no longer meet its damage tolerance requirements. Therefore, the FAA has determined that a high frequency eddy current (HFEC) inspection of all affected structural elements of the main deck cargo door, and replacement of any cracked part with a new part having the same part number are necessary to prevent reduced structural integrity of the main deck cargo door, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved Pemco Service Bulletin 737-52-0037, including Attachment 1, dated August 10, 2000. The service bulletin describes procedures for an HFEC inspection to detect cracks of the lower frames and reinforcing angles of the main deck cargo door where the door latch fittings attach between FS 361.87 and FS 498.12 and WL 202.35 and WL 213.00, and replacement of any cracked part with a new part having the same part number.

Explanation of Requirements of the Rule

Since the unsafe condition described is likely to exist or develop on other airplanes of the same type design, the FAA issued emergency AD 2000-17-51 to detect and correct cracking of the lower portion of the main deck cargo door frames, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane. The AD supersedes AD 2000-13-51 to require a one-time HFEC inspection to detect cracks of the lower frames and reinforcing angles of the main deck cargo door where the door latch fittings attach between FS 361.87 and FS 498.12 and WL 202.35 and WL 213.00, and replacement of any cracked part with a new part having the same part number. The actions are required to be accomplished in accordance with the service bulletin previously described.

Since it was found that immediate corrective action was required, notice and opportunity for prior public comment thereon were impracticable and contrary to the public interest, and good cause existed to make the AD effective immediately by individual notices issued on August 14, 2000, to all known U.S. owners and operators of certain Boeing Model 737-200 and -300 series airplanes. These conditions still exist, and the AD is hereby published in the Federal Register as an amendment to section 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make it effective to all persons.

Interim Action

The FAA is considering further rulemaking action to supersede this AD to require replacement of the main deck cargo door frames and reinforcing angles that have accumulated 7,000 or more total flight cycles with new parts. However, the planned compliance time for these actions is sufficiently long so that prior notice and time for public comment will be practicable.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this 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 under the caption ADDRESSES. All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the 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 that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket.

Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this rule must submit a self-addressed, stamped postcard on which the following statement is made: “Comments to Docket Number 2000-NM-277-AD.” The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein 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. Therefore, it is determined that this final rule does not have federalism implications under Executive Order 13132.

The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and that it is not a “significant regulatory action” under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• Incorporation by reference
• Safety

Adoption of the Amendment

Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (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. Section 39.13 is amended by removing amendment 39-11826 ( 65 FR 44977, July 20, 2000), and by adding a new airworthiness directive (AD), amendment 39-11877, to read as follows:

2000-17-51 Boeing: Amendment 39-11877. Docket 2000-NM-277-AD. Supersedes AD 2000-13-51, Amendment 39-11826.

Applicability: Model 737-200 and -300 series airplanes equipped with a main deck cargo door installed in accordance with Supplemental Type Certificate (STC) SA2969SO, certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been otherwise modified, altered, or repaired in the area subject to the requirements of this AD. For airplanes that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (b) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To detect and correct cracking of the lower portion of the main deck cargo door frames, which could result in sudden depressurization, loss or opening of the main deck cargo door during flight, and loss of control of the airplane, accomplish the following:

One-Time Inspection and Corrective Action, If Necessary

(a) Within 7 days after the effective date of this AD, perform a one-time high frequency eddy current inspection to detect cracks of the lower frames and reinforcing angles of the main deck cargo door where the door latch fittings attach between fuselage station (FS) 361.87 and FS 498.12 and water line (WL) 202.35 and WL 213.00, in accordance with the inspection procedures specified in paragraph 3.D.(1) of the Accomplishment Instructions of Pemco Service Bulletin 737-52-0037, including Attachment 1, dated August 10, 2000. If any crack is detected, prior to further flight, replace the cracked part with a new part having the same part number, in accordance with paragraph 3.D.(2) of the Accomplishment Instructions of the service bulletin.

Alternative Methods of Compliance

(b) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Atlanta Aircraft Certification Office (ACO), FAA. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Atlanta ACO.

Note 2:

Information concerning the existence of approved alternative methods of compliance with this AD, if any, may be obtained from the Atlanta ACO.

Special Flight Permits

(c) Special flight permits may be issued in accordance with §§ 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the airplane to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(d) The actions shall be done in accordance with Pemco Service Bulletin 737-52-0037, including Attachment 1, dated August 10, 2000. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Pemco World Air Services, 100 Pemco Drive, Dothan, AL 36303. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the FAA, Atlanta Aircraft Certification Office, One Crown Center, 1895 Phoenix Boulevard, Suite 450, Atlanta, Georgia; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(e) This amendment becomes effective on August 30, 2000, to all persons except those persons to whom it was made immediately effective by emergency AD 2000-17-51, issued on August 14, 2000, which contained the requirements of this amendment.

Issued in Renton, Washington, on August 18, 2000.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.