01-9764. Airworthiness Directives; Boeing Model 737-600, -700, -800, and -700C Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment supersedes an existing airworthiness directive (AD), applicable to certain Boeing Model 737-600, -700, -800, and -700C series airplanes, that currently requires initial and repetitive inspections of the elevator tab assembly to detect any damage or discrepancy; and corrective actions, if necessary. This amendment clarifies the applicability and certain requirements of the AD. This amendment is prompted by requests for such clarification. The actions specified in this AD are intended to prevent excessive in-flight vibrations of the elevator tab, which could lead to loss of the elevator tab and reduced controllability of the airplane.

DATES:

Effective May 7, 2001.

The incorporation by reference of certain publications listed in the regulations was approved previously by the Director of the Federal Register as of March 20, 2001 (66 FR 13229, March 5, 2001).

Comments for inclusion in the Rules Docket must be received on or before June 19, 2001.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-48-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. 2001-NM-48-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 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; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Nancy Marsh, 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:

On February 21, 2001, the FAA issued AD 2001-04-08, amendment 39-12127 (66 FR 13229, March 5, 2001), applicable to certain Boeing Model 737-600, -700, -800, and -700C series airplanes, to require initial and repetitive inspections of the elevator tab assembly to detect any damage or discrepancy; and corrective actions, if necessary. That action was prompted by numerous reports of excessive in-flight vibrations of the elevator tab on Model 737-600, -700, and -800 series airplanes. The actions required by that AD are intended to prevent excessive in-flight vibrations of the elevator tab, which could lead to loss of the elevator tab and reduced controllability of the airplane.

Comments Received Since Issuance of Previous Rule

Since the issuance of that AD, the FAA has received a request for clarification of the applicability of the existing AD, which points to airplanes listed in Revision 1 of Boeing Alert Service Bulletin 737-55A1072. We find that, as written, the applicability of the AD could be misinterpreted to mean that future production airplanes or Model 737-700C series airplanes are not affected because the service bulletin does not specifically mention those airplanes. Since we intended that the requirements of that AD apply to all Model 737-600, -700, -800, and -700C series airplanes, including future production airplanes, the applicability of this AD has been revised to read as follows: “All Model 737-600, -700, -800, and -700C series airplanes, certificated in any category.”

In addition, we received a request for clarification as to whether operators are required to report results of inspection findings. This question arises because paragraphs (a) through (d) of the existing AD include a reference to “Appendix A” of the alert service bulletin. That Appendix consists of a form on which inspection findings are documented and submitted. We agree that clarification is necessary. The reference to Appendix A of the alert service bulletin should not have been included as part of the alert service bulletin citation, and has been removed from this AD. This AD does not require that operators report results of inspection findings to the FAA.

Clarification of Repetitive Inspection Requirement

We also have determined that the requirements of paragraph (c)(2) of the existing AD require clarification. We intended that repetitive inspections be done on all airplanes, whether or not any damage or discrepancy is found when doing the inspection required by paragraph (c) or when doing the corrective actions per paragraph (c)(2) of the AD. These repetitive inspections were specified in Table 1 of the preamble of the existing AD. We have changed paragraph (c)(2) to clarify this requirement.

Explanation of Requirements of Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of this same type design, this AD supersedes AD 2001-04-08 to continue to require initial and repetitive inspections of the elevator tab assembly to detect any damage or discrepancy; and corrective actions, if necessary. This AD clarifies the applicability and certain requirements of the existing AD.

Determination of Rule's Effective Date

Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

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.

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 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 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 2001-NM-48-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 39-12127 ( 66 FR 13229, March 5, 2001), and by adding a new airworthiness directive (AD), amendment 39-12186, to read as follows:

2001-08-09 Boeing: Amendment 39-12186. Docket 2001-NM-48-AD. Supersedes AD 2001-04-08, Amendment 39-12127.

Applicability: All Model 737-600, -700, -800, and -700C series airplanes, certificated in any category.

Note 1:

This AD applies to each airplane identified in the preceding applicability provision, regardless of whether it has been 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 (e) 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 prevent excessive in-flight vibrations of the elevator tab, which could lead to loss of the elevator tab and reduced controllability of the airplane, accomplish the following:

Initial and Repetitive Inspections, and Corrective Actions (Work Package I)

(a) Within 30 days or 100 flight cycles after March 20, 2001 (the effective date of AD 2001-04-08, amendment 39-12127), whichever occurs later: Inspect the elevator tab, as specified in the Accomplishment Instructions for Work Package I of Boeing Alert Service Bulletin 737-55A1072, Revision 1, dated January 11, 2001, to detect any damage or discrepancy per the service bulletin.

(1) If no damage or discrepancy (including loose or missing parts, or excessive wear) is found, repeat the inspections required by paragraph (a) of this AD thereafter at intervals not to exceed 250 flight cycles.

(2) Except as provided by paragraph (d) of this AD, if any damage or discrepancy is found, before further flight, do the corrective actions (including follow-on inspections; replacing, reworking, repairing, and lubricating parts; applying inspection putty; cleaning; and aligning and torqueing components) specified in Figure 1 of the service bulletin, as applicable. Repeat the inspections required by paragraph (a) of this AD thereafter at intervals not to exceed 250 flight cycles.

One-Time Freeplay Inspections and Corrective Actions (Work Package II)

(b) Within 90 days after March 20, 2001, or before the accumulation of 750 total flight cycles after airplane delivery, whichever occurs later: Do the one-time free-play inspections of the elevator tab, as specified in the Accomplishment Instructions for Work Package II of Boeing Alert Service Bulletin 737-55A1072, Revision 1, dated January 11, 2001, to detect any damage or discrepancy per the service bulletin.

(1) If no damage or discrepancy is found, no further action is required by this paragraph.

(2) If any damage or discrepancy is found, before further flight, do the corrective actions specified in Figures 2 and 3 of the service bulletin, as applicable.

Repetitive Inspections and Corrective Actions (Work Package III)

(c) Within 1,500 flight hours or 750 flight cycles, whichever occurs earlier, after doing Work Package II: Inspect the elevator tab, as specified in the Accomplishment Instructions for Work Package III of Boeing Alert Service Bulletin 737-55A1072, Revision 1, dated January 11, 2001, to detect any damage or discrepancy per the service bulletin.

(1) If no damage or discrepancy is found, repeat the inspections required by paragraph (c) of this AD thereafter at intervals not to exceed 1,500 flight hours or 750 flight cycles, whichever occurs earlier.

(2) If any damage or discrepancy is found, before further flight, do the applicable corrective actions specified in Figure 2, as specified by the Accomplishment Instructions for Work Package III, of the service bulletin. Thereafter, repeat the inspections required by paragraph (c) of this AD at intervals not to exceed 1,500 flight hours or 750 flight cycles, whichever occurs earlier.

Repair

(d) Repair any damage or discrepancy of the elevator tab assembly that is outside the limits specified by the Accomplishment Instructions of Boeing Alert Service Bulletin 737-55A1072, Revision 1, dated January 11, 2001, 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. For a repair method to be approved by the Manager, Seattle ACO, as required by this paragraph, the Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

(e) 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, Seattle ACO. Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, Seattle ACO.

Note 2:

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

Special Flight Permits

(f) Special flight permits may be issued in accordance with sections 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

(g) Except as provided by paragraph (d) of this AD, the actions shall be done in accordance with Boeing Alert Service Bulletin 737-55A1072, Revision 1, dated January 11, 2001. This incorporation by reference was approved previously by the Director of the Federal Register as of March 20, 2001 (66 FR 13229, March 5, 2001). Copies may be obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be inspected at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the Office of the Federal Register, 800 North Capitol Street, NW., suite 700, Washington, DC.

Effective Date

(h) This amendment becomes effective on May 7, 2001.

Issued in Renton, Washington, on April 13, 2001.

Donald L. Riggin,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.