AD 2000-07-09

Effective April 25, 2000.

The incorporation by reference of certain publications listed in the regulations is approved by the Director of the Federal Register as of April 25, 2000.

Comments for inclusion in the Rules Docket must be received on or before June 9, 2000.

Submit comments in triplicate to the Federal Aviation Administration (FAA), Transport Airplane Directorate, ANM-114, Attention: Rules Docket No. 2000-NM-84-AD, 1601 Lind Avenue, SW., Renton, Washington 98055-4056.

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.

Kenneth W. Frey, Aerospace Engineer, Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 227-2673; fax (425) 227-1181.

The FAA received several reports indicating that operators found loose nuts on the bolts that connect the lower input crank arm and the vernier adjustment input rod of the elevator power control unit (PCU). Apparently, maintenance had not been accomplished on the PCU's since delivery of the airplanes from the manufacturer. One of the loose PCU input rod nuts was found on a production airplane during a line check. The loose nuts reported had been finger tightened, but had not been properly torqued on the bolts.

Loose nuts on the bolts of the input rod of the elevator PCU could result in the loss of pivot bolts on the crank arms of the elevator PCU's, and consequent loss of control of the airplane during takeoff and landing.

The FAA has reviewed and approved Boeing Telegraphic Service Letter 737-SL-27-150, dated February 14, 2000, which describes procedures for a one-time visual inspection to determine if the nuts installed on the bolts at each end of the input rods connected to each elevator power control unit (PCU) are installed correctly, and tightening of any loose nut that is found.

Since an unsafe condition has been identified that is likely to exist or develop on other Boeing Model 737-600, -700, and -800 series airplanes of the same type design, this AD is being issued to prevent loss of control of the airplane during takeoff and landing due to loose nuts on the bolts of the input crank arms of the elevator PCU, and consequent loss of pivot bolts on the PCU. This AD requires a one-time general visual inspection to determine if the nuts installed on the bolts at each end of the input rods connected to each elevator PCU are installed correctly, and corrective action, if necessary. The actions are required to be accomplished in accordance with the telegraphic service letter described previously.

This AD also requires that operators report findings of loose nuts to the FAA.

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.

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-84-AD.” The postcard will be date stamped and returned to the commenter.

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.

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:

1. The authority citation for part 39 continues to read as follows:

2. Section 39.13 is amended by adding the following new airworthiness directive: