01-29427. Airworthiness Directives; Boeing Model 737-600, -700, -700C, and -800 Series Airplanes

AGENCY:

Federal Aviation Administration, DOT.

ACTION:

Notice of proposed rulemaking (NPRM).

SUMMARY:

This document proposes the adoption of a new airworthiness directive (AD) that is applicable to certain Boeing Model 737-600, -700, -700C, and -800 series airplanes. This proposal would require a one-time inspection of certain fasteners in rudder pedal housings to determine if pan-head fasteners are installed, and replacement of existing fasteners with improved fasteners, if necessary. This action is necessary to prevent loss of free movement of the rudder pedals, which could result in reduced controllability of the airplane. This action is intended to address the identified unsafe condition.

DATES:

Comments must be received by January 11, 2002.

ADDRESSES:

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2001-NM-37-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-37-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 the proposed rule 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.

FOR FURTHER INFORMATION CONTACT:

Barbara Mudrovich, 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:

Comments Invited

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 2001-NM-37-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. 2001-NM-37-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

Discussion

The FAA has received a report indicating that, during a check of the flight controls by the captain, a rudder pedal on a Boeing Model 737-800 series airplane caught on a pan-head fastener on the upper cover assembly of the rudder pedal housing. Further investigation revealed that this condition may occur when the rudder pedal for either the captain or first officer is adjusted to the full-forward position and a side load is applied to the rudder pedal. This condition, if not corrected, could prevent free movement of the pedal, and result in reduced controllability of the airplane.

The fasteners on the upper cover assembly of the rudder pedal housing on certain Boeing Model 737-600, -700, and -700C series airplanes may be the same as those installed on Model 737-800 series airplanes. Therefore, those airplanes may also be subject to the same unsafe condition described above.

Airplanes after line number 295 have been delivered with flush-head fasteners installed in the subject area, and are not subject to this unsafe condition.

Explanation of Relevant Service Information

We have reviewed and approved Boeing Alert Service Bulletin 737-25A1383, Revision 1, dated December 2, 1999, which describes procedures for a one-time inspection of fasteners on the upper cover assembly of the housing for the captain's and first officer's rudder pedals to determine if pan-head fasteners are installed, and replacement of all pan-head fasteners with improved (flush-head) fasteners, including countersink-drilling of the fastener holes. 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 Proposed AD and Service Bulletin

The proposed AD differs from the service bulletin in the following ways:

• The service bulletin recommends that the actions therein be done as soon as manpower and materials are available. However, we find that such a compliance time may not ensure that the necessary actions are completed in a timely manner. Therefore, this proposed AD would require the replacement of all pan-head bolts with improved bolts within 12 months after the effective date of this AD.
• The effectivity listing of the service bulletin identifies only Model 737-600, -700, and -800 series airplanes as being subject to the actions described therein. However, in reviewing the effectivity listing, the FAA finds that Model 737-700C series airplanes are also included. Therefore, Model 737-700C series airplanes are included in the applicability statement in this proposed AD.
• The service bulletin does not specify what type of inspection is needed to determine if pan-head fasteners are installed on the upper cover assembly of the housing for the captain's and first officer's rudder pedals. The FAA has determined that the procedures in the service bulletin describe a general visual inspection. Note 2 of this proposed AD defines that type of inspection.

Cost Impact

There are approximately 264 airplanes of the affected design in the worldwide fleet. The FAA estimates that 123 airplanes of U.S. registry would be affected by this proposed AD, that it would take approximately 1 work hour per airplane to accomplish the proposed inspection, 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 $7,380, or $60 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 the time required to gain access and close up, planning time, or time necessitated by other administrative actions.

Should an operator be required to accomplish the replacement of fasteners, it would take approximately 2 work hours per airplane to accomplish the repair, at an average labor rate of $60 per work hour. Required parts would be provided by the manufacturer at no cost to the operator. Based on these figures, the cost impact of any repair action is estimated to be $120 per airplane.

Regulatory Impact

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.

List of Subjects in 14 CFR Part 39

• Air transportation
• Aircraft
• Aviation safety
• 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:

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:

Boeing: Docket 2001-NM-37-AD.

Applicability: Model 737-600, -700, -700C, and -800 series airplanes; line numbers 1 through 295 inclusive; 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 loss of free movement of the rudder pedals, which could result in reduced controllability of the airplane, accomplish the following:

Replacement of Fasteners

(a) Within 12 months after the effective date of this AD, do a one-time general visual inspection of the fasteners on the upper cover assembly of the housing for the captain's and first officer's rudder pedals to determine if pan-head fasteners are installed, according to Boeing Alert Service Bulletin 737-25A1383, Revision 1, dated December 2, 1999. Replace all pan-head fasteners on the upper cover assembly of the housing for the captain's and first officer's rudder pedals with improved (flush-head) fasteners, including countersink-drilling the fastener holes, 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.

Issued in Renton, Washington, on November 20, 2001.

Kalene C. Yanamura,

Acting Manager, Transport Airplane Directorate, Aircraft Certification Service.