AD 98-13-12 R1

The FAA has received a report from an operator indicating that, on a Boeing Model 737-400 series airplane, during rollout after landing, the captain's right rudder pedal moved to the full travel position when it was pushed. The pedal failed to return to its normal position after it was released even though the rudder remained at the neutral position. Consequently, the first officer used his rudder pedals to control the rudder and the nose wheel steering. Investigation revealed that the forward end of the pushrod on the right rudder pedal was not connected to the rudder pedal assembly. The nut and washer of the pushrod were found in the lower forward compartment. This airplane had accumulated 17,600 total flight hours and 7,900 total flight cycles. A second operator reported that a pilot felt a loose rudder pedal. Investigation revealed that the fastener connecting the pushrod to the rudder pedal assembly was loose.

In addition, on a Boeing Model737-500 series airplane, a nut that connects the pushrod to the rudder pedal assembly was loose. This airplane had accumulated 3,012 total flight hours and 2,658 total flight cycles. Maintenance inspections of 130 in-service Boeing Model 737 series airplanes revealed four other loose fasteners.

The cause of the loose and missing nuts and bolts has been attributed to incorrect installation of the fasteners that connect the pushrods to the rudder pedal assemblies during manufacture. If the nut is not installed correctly, the bolt can fall out or may be able to move far enough to touch the opposite rudder pedal assembly. These conditions, if not corrected, could result in potential loss of rudder control, jamming of the rudder system, uncommanded movement of the rudder system, and consequent reduced controllability of the airplane.

The rudder pedal assemblies on certain Boeing Model 747, 757, 767, and 777 series airplanes are similar in design to those on the affected Model 737 series airplanes. Therefore, the rudder pedal assemblies on all of these models may have been installed incorrectly. Consequently, all of these models may be subject to the same unsafe condition.

Explanation of Relevant Service Information

The FAA has reviewed and approved Boeing Alert Service Bulletins 737-27A1212, 747-27A2368, 757-27A0128, 767-27A0156, and 777-27A0029, all dated March 26, 1998. These alert service bulletins describe procedures for a one-time inspection to detect discrepancies of the fasteners (nuts, bolts, and washers) that connect the forward ends of the pushrods to the rudder pedal assemblies; and corrective actions, if necessary. Corrective actions include tightening nuts and bolts to specified torque limits, installing missing fasteners, and replacing incorrectly installed fasteners with new fasteners.

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 loss of rudder control, jamming of the rudder system, uncommanded movement of the rudder system, and consequent reduced controllability of the airplane, due to loose or missing fasteners that connect the pushrods to the rudder pedal assemblies. This AD requires accomplishment of the actions specified in the alert service bulletins described previously. This AD also requires that operators report results of findings of discrepancies to the FAA and to Boeing.

Interim Action

This is considered to be interim action until final action is identified, at which time the FAA may consider further rulemaking.

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 InvitedAlthough 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 suggesta 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 98-NM-156-AD." The postcard will be date stamped and returned to the commenter.

Regulatory Impact

The regulations adopted herein will not have substantial direct effects 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, in accordance with Executive Order 12612, it is determined that this final rule does not have sufficient federalism implications to warrant the preparation of a Federalism Assessment.

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: