[Federal Register Volume 66, Number 126 (Friday, June 29, 2001)]
[Proposed Rules]
[Pages 34591-34593]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 01-16382]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-20-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD); applicable to certain Boeing Model 737-
600, -700, and -800 series airplanes; that currently requires 
repetitive inspections of certain elevator hinge plates, and corrective 
action, if necessary. That AD also provides for an optional replacement 
of the elevator hinge plates with new, improved hinge plates, which 
would end the repetitive inspections. This action proposes to require 
accomplishment of the previously optional replacement of the elevator 
hinge plates with new, improved hinge plates, as terminating action for 
the repetitive inspections. This action is necessary to prevent fatigue 
cracking of the elevator hinge plates, which could lead to the loss of 
the attachment of the elevator to the horizontal stabilizer, and 
consequent reduced controllability of the airplane. This action is 
intended to address the identified unsafe condition.

DATES: Comments must be received by August 13, 2001.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-20-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 (425) 227-1232. 
Comments may also be sent via the Internet using the following address: 
<a href="/cdn-cgi/l/email-protection#b38a9ed2ddde9eddc3c1ded0dcdeded6ddc7f3d5d2d29dd4dcc5"><span class="__cf_email__" data-cfemail="a89185c9c6c585c6d8dac5cbc7c5c5cdc6dce8cec9c986cfc7de">[email protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-20-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: Nancy Marsh, Aerospace Engineer, 
Airframe Branch, ANM-120S, FAA, Seattle Aircraft Certification Office, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425) 
227-2028; fax (425) 227-1181.

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:
    <bullet> 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.
    <bullet> For each issue, state what specific change to the proposed 
AD is being requested.
    <bullet> 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-20-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-20-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On March 15, 2001, the FAA issued AD 2001-06-08, amendment 39-12155 
(66 FR 16116, March 23, 2001); applicable to certain Boeing Model 737-
600, -700, and -800 series airplanes; to require repetitive inspections 
of certain elevator hinge plates, and corrective action, if necessary. 
That AD also provides for an optional replacement of the elevator hinge 
plates with new, improved hinge plates, which would end the repetitive 
inspections. That action was prompted by a report that--during flight 
testing of Boeing Model 737-600, -700, and -800 series airplanes--the 
elevator hinge plates at elevator hinges 3, 4, 5, 6, 7, and 8 
experienced higher-than-expected loads due to buffeting by the spoiler. 
The requirements of that AD are intended to detect and correct fatigue 
cracking of the elevator hinge plates, which could lead to the loss of 
the attachment of the elevator to the horizontal stabilizer, and 
consequent reduced controllability of the airplane.

Actions Since Issuance of Previous Rule

    In the preamble to AD 2001-06-08, the FAA indicated that the 
actions required by that AD were considered ``interim action'' and that 
further rulemaking action was being considered to require the 
replacement of the elevator hinge plates with new parts, which was 
provided as optional in AD 2001-06-08, and which would terminate the 
repetitive inspections currently required by that AD. The FAA now has 
determined that further rulemaking action is indeed necessary,

[[Page 34592]]

and this proposed AD follows from that determination.

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 supersede AD 2001-06-08 to continue to require 
repetitive inspections of certain elevator hinge plates, and corrective 
action, if necessary. The proposed AD would add a new requirement for 
replacement of the elevator hinge plates with new, improved hinge 
plates, which would end the repetitive inspections. Except as discussed 
below, the actions would be required to be accomplished in accordance 
with Boeing Service Bulletin 737-55-1067, dated October 19, 2000, which 
was described in AD 2001-06-08.

Difference Between This Proposed AD and the Service Bulletin

    Although the service bulletin specifies to contact Boeing for wear 
limits during replacement of elevator hinge plates, this AD requires 
that such wear limits be obtained from the Manager, Seattle Aircraft 
Certification Office (ACO), FAA, or a Boeing Company Designated 
Engineering Representative who has been authorized by the Manager, 
Seattle ACO, to make such findings.

Cost Impact

    There are approximately 84 airplanes of the affected design in the 
worldwide fleet. The FAA estimates that 39 airplanes of U.S. registry 
would be affected by this proposed AD.
    The inspections that are currently required by AD 2001-06-08 take 
approximately 4 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Based on these figures, the cost 
impact of the currently required actions on U.S. operators is estimated 
to be $9,360, or $240 per airplane, per inspection cycle.
    The new replacement that is proposed in this AD action would take 
approximately 44 work hours per airplane to accomplish, at an average 
labor rate of $60 per work hour. Required parts would cost 
approximately $13,116 per airplane. Based on these figures, the cost 
impact of the proposed requirements of this AD on U.S. operators is 
estimated to be $614,484, or $15,756 per airplane.
    The cost impact figures discussed above are 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.

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.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing amendment 39-12155 (66 FR 
16116, March 23, 2001), and by adding a new airworthiness directive 
(AD), to read as follows:

Boeing: Docket 2001-NM-20-AD. Supersedes AD 2001-06-08, Amendment 
39-12155.

    Applicability: Model 737-600, -700, and -800 series airplanes; 
line numbers 1 through 84 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 (d) 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 fatigue cracking of the elevator hinge plates, which 
could lead to the loss of the attachment of the elevator to the 
horizontal stabilizer, and consequent reduced controllability of the 
airplane, accomplish the following:

Restatement of Requirements of AD 2001-06-08

Inspections and Corrective Actions

    (a) Prior to the accumulation of 7,000 total flight cycles or 
within 90 days after April 9, 2001 (the effective date of AD 2001-
06-08), whichever occurs later, perform high frequency eddy current 
and detailed visual inspections of the hinge plate at elevator hinge 
4, and a detailed visual inspection of the elevator hinge plate lugs 
(three locations) at elevator hinges 3, 5, 6, 7, and 8. Do these 
inspections per Part I of the Accomplishment Instructions of Boeing 
Service Bulletin 737-55-1067, dated October 19, 2000. Repeat the 
inspections thereafter no later than every 4,000 flight cycles, per 
the service bulletin, until paragraph (b) of this AD has been 
accomplished. If any cracking or unusual wear (i.e., elongated 
holes, loose or missing nuts or bolts, or missing primer or finish) 
is found during any inspection per this paragraph, before further 
flight, replace the affected hinge plate with a new, improved hinge 
plate, and modify the elevator upper skin, the upper and lower hinge 
covers, and the upper and lower closure panels, as applicable, per 
the service bulletin, except as provided by paragraph (c) of this 
AD. Such replacement and modification ends the repetitive 
inspections for the replaced hinge plate.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''


[[Page 34593]]



New Requirements of This AD

Replacement of Hinge Plates

    (b) Before the accumulation of 15,000 total flight cycles, or 
within 5 years since the airplane's date of manufacture, whichever 
occurs first: Replace the elevator hinge plates at hinges 3, 4, 5, 
6, 7, and 8, with new, improved hinge plates; per Part II of the 
Accomplishment Instructions of Boeing Service Bulletin 737-55-1067, 
dated October 19, 2000, except as provided by paragraph (c) of this 
AD. The replacement includes modification of the elevator upper 
skin, the upper and lower hinge covers, and the upper and lower 
closure panels, as applicable. Doing this replacement ends the 
repetitive inspections required by this AD.

Exception to Service Bulletin Instructions: Wear Limits

    (c) During the replacement of elevator hinge plates per 
paragraph (a) or (b) of this AD, where Boeing Service Bulletin 737-
55-1067, dated October 19, 2000, specifies to contact Boeing for 
wear limits, before further flight, contact the Manager, Seattle 
Aircraft Certification Office (ACO), FAA, or a Boeing Company 
Designated Engineering Representative who has been authorized by the 
Manager, Seattle ACO, to make such findings. For wear limits to be 
approved by the Manager, Seattle ACO, as required by this paragraph, 
the Manager's approval letter must specifically reference this AD.

Alternative Methods of Compliance

    (d) 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. 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

    (e) 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.

    Issued in Renton, Washington, on June 22, 2001.
Kalene C. Yanamura,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 01-16382 Filed 6-28-01; 8:45 am]
BILLING CODE 4910-13-U


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