02-6328. Airworthiness Directives; Boeing Model 737-600, -700, -700C, and -800 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Final rule; request for comments.

SUMMARY:

This amendment adopts a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. This action requires measurement of clearance between a certain retention bracket for the elevator power control unit (PCU) and a quadrant on the inboard side of the right elevator PCU, inspection for loose fasteners in certain retention bracket assemblies for the left and right elevator PCUs, and corrective action, if necessary. This action is necessary to prevent jamming of the elevator flight controls, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Effective April 3, 2002.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 3, 2002.

Comments for inclusion in the Rules Docket must be received on or before May 20, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-356-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-356-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:

Kenneth J. Fairhurst, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone [phone]; fax [phone].

SUPPLEMENTARY INFORMATION:

The FAA has received reports of loose fasteners in certain retention bracket assemblies for the left and right elevator power control units (PCUs) on certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. Such loose fasteners could separate from the bracket and interfere with adjacent systems, including the elevator flight controls. A loose bracket could also cause such interference. Also, operators have found inadequate clearance between a particular retention bracket for the elevator PCU and a quadrant on the inboard side of the right elevator PCU. These conditions, if not corrected, could result in jamming of the elevator flight controls, which could result in reduced controllability of the airplane.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletin 737-27A1234, dated March 27, 2000, and Revision 1, dated August 10, 2000. Both service bulletins describe procedures for measurement of clearance between a certain retention bracket for the elevator PCU and a quadrant on the inboard side of the right elevator PCU, and rework of the bracket, if necessary. The service bulletins also describe procedures for a visual inspection for loose fasteners in certain retention bracket assemblies for the left and right elevator PCUs, and torquing of the fasteners, if necessary. The visual inspection for loose fasteners consists of inspecting for inadequate thread protrusion, gaps between the fastener heads and brackets, or loose brackets. Revision 1 differs from the original issue of the service bulletin in that the effectivity listing of Revision 1 includes airplanes not listed in the original issue of the service bulletin. Accomplishment of the actions specified in the service bulletin is intended to adequately address the identified unsafe condition.

Explanation of the Requirements of the Rule

Since an unsafe condition has been identified that is likely to exist or develop on other airplanes of the same type design, this AD is being issued to prevent jamming of the elevator flight controls, which could result in reduced controllability of the airplane. This AD requires accomplishment of the actions specified in the service bulletin described previously.

The FAA acknowledges that many operators have already accomplished the actions required by this AD on their fleets in accordance with the original issue or Revision 1 of Boeing Alert Service Bulletin 737-27A1234, which had a recommended compliance time of 10 days after receipt of the service bulletin. No further action is necessary for those airplanes on which the actions in the referenced service bulletins have been accomplished. However, the FAA finds that issuance of an AD is warranted at this time to ensure that the actions in the service bulletin are accomplished and the identified unsafe condition is addressed on all affected airplanes.

Difference Between This AD and the Service Bulletin

The service bulletin described previously identifies only Boeing Model 737-600, -700, and -800 series airplanes as being affected by the actions therein. However, we find that the effectivity listing of the service bulletin also includes Model 737-700C series airplanes. Therefore, this AD applies to certain Model 737-700C series airplanes in addition to certain Boeing Model 737-600, -700, and -800 series airplanes.

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-356-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 adding the following new airworthiness directive:

2002-06-03 Boeing: Amendment 39-12679. Docket 2001-NM-356-AD.

Applicability: Model 737-600, -700, -700C, and -800 series airplanes; as listed in Boeing Alert Service Bulletin 737-27A1234, Revision 1, dated August 10, 2000; 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 (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 prevent jamming of the elevator flight controls, which could result in reduced controllability of the airplane, accomplish the following:

Measurement of Clearance and General Visual Inspection

(a) Within 10 days after the effective date of this AD, do paragraphs (a)(1) and (a)(2) of this AD, according to Boeing Alert Service Bulletin 737-27A1234, dated March 27, 2000, or Revision 1, dated August 10, 2000.

(1) Measure the clearance between a certain retention bracket for the elevator power control unit (PCU) and a quadrant on the inboard side of the right elevator PCU. If clearance is less than 0.10 inch, before further flight, accomplish rework according to the service bulletin.

(2) Perform a one-time general visual inspection for loose fasteners or brackets in certain retention bracket assemblies for the left and right elevator PCUs. If any loose fastener or bracket is found, before further flight, torque affected fasteners, according to the service bulletin.

Note 2:

For the purposes of this AD, a general visual inspection is defined as: “A visual examination of an interior or exterior area, installation, or assembly to detect obvious damage, failure, or irregularity. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight, or drop-light, and may require removal or opening of access panels or doors. Stands, ladders, or platforms may be required to gain proximity to the area being checked.”

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, Seattle 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, Seattle ACO.

Note 3:

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

(c) 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

(d) The actions shall be done in accordance with Boeing Alert Service Bulletin 737-27A1234, dated March 27, 2000, or Boeing Alert Service Bulletin 737-27A1234, Revision 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 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

(e) This amendment becomes effective on April 3, 2002.

Issued in Renton, Washington, on March 11, 2002.

Ali Bahrami,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.