Airworthiness Directives; Boeing Model 737-600, -700, and 800 Series Airplanes

[Federal Register Volume 65, Number 69 (Monday, April 10, 2000)]
[Rules and Regulations]
[Pages 18879-18881]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-8392]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2000-NM-84-AD; Amendment 39-11663; AD 2000-07-09]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, and 800 
Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Boeing Model 737-600, -700, and 800 series 
airplanes. This action requires a one-time inspection to detect loose 
nuts installed on the bolts at each end of the input rods connected to 
each elevator power control unit (PCU), and corrective action, if 
necessary. This amendment is prompted by reports of loose nuts on the 
bolts that connect the lower input crank arm and the vernier adjustment 
input rod of the elevator PCU. The actions specified in this AD are 
intended to detect and correct loose nuts on the bolts of the input 
crank arms of the elevator PCU, which could result in the loss of pivot 
bolts on the PCU and consequent loss of control of the airplane during 
takeoff and landing.

DATES: 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.

ADDRESSES: 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.

FOR FURTHER INFORMATION CONTACT: 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.

SUPPLEMENTARY INFORMATION: 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

[[Page 18880]]

loss of control of the airplane during takeoff and landing.

Explanation of Relevant Service Information

    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.

Explanation of the Requirements of the Rule

    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.

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.
    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.

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.


Sec. 39.13  [Amended]

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

2000-07-09 Boeing: Amendment 39-11663. Docket 2000-NM-84-AD.

    Applicability: Model 737-600, -700, and -800 series airplanes, 
line numbers 1 through 477 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 (c) 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 control of the airplane during takeoff and 
landing due to loose nuts on the bolts of the input crank arms of 
the elevator power control unit (PCU), and consequent loss of pivot 
bolts, accomplish the following:

    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.''

    (a) Within 30 days after the effective date of this AD, perform 
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, in accordance with Boeing 
Telegraphic Service Letter 737-SL-27-150, dated February 14, 2000.
    (1) If all bolts are protruding through the nuts, no further 
action is required by this AD.
    (2) If any bolt does not protrude through the nut, prior to 
further flight, tighten the nut in accordance with the telegraphic 
service letter.
    (b) Within 10 days after accomplishing the inspection required 
by this AD; or within 10 days after the effective date of this AD if 
the inspection was accomplished prior to the

[[Page 18881]]

effective date of this AD: Submit a report of any findings of loose 
nuts to the Manager, Seattle Aircraft Certification Office (ACO), 
FAA, Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington 98055-4056; fax (425) 227-1181. The report must include 
the operator's name, the date the inspection was accomplished, the 
airplane line number, and the number of loose nuts found on that 
airplane. Information collection requirements contained in this 
regulation have been approved by the Office of Management and Budget 
(OMB) under the provisions of the Paperwork Reduction Act of 1980 
(44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number 
2120-0056.

Alternative Methods of Compliance

    (c) 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, FAA, Transport 
Airplane Directorate. 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

    (d) Special flight permits may be issued in accordance with 
Secs. 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

    (e) The actions shall be done in accordance with Boeing 
Telegraphic Service Letter 737-SL-27-150, dated February 14, 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.
    (f) This amendment becomes effective on April 25, 2000.

    Issued in Renton, Washington, on March 30, 2000.
Donald L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 00-8392 Filed 4-7-00; 8:45 am]
BILLING CODE 4910-13-P

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