[Federal Register Volume 69, Number 153 (Tuesday, August 10, 2004)]
[Proposed Rules]
[Pages 48424-48426]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 04-18221]


 ========================================================================
 Proposed Rules
                                                 Federal Register
 ________________________________________________________________________
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 This section of the FEDERAL REGISTER contains notices to the public of 
 the proposed issuance of rules and regulations. The purpose of these 
 notices is to give interested persons an opportunity to participate in 
 the rule making prior to the adoption of the final rules.
 
 ========================================================================
 

  Federal Register / Vol. 69, No. 153 / Tuesday, August 10, 2004 / 
Proposed Rules  

[[Page 48424]]



DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2004-18814; Directorate Identifier 2003-NM-286-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-100, -200, -200C, -
300, -400, and -500 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. This proposed AD would require repetitive inspections for 
discrepancies of the elevator tab control rod assemblies and/or damage 
to the surrounding structure, and related corrective action. This 
proposed AD is prompted by reports indicating loose jam nuts and/or 
thread wear at the rod ends on the elevator tab control rod assembly. 
We are proposing this AD to find and fix excessive freeplay in the tab 
control mechanism, which could result in elevator tab flutter and 
consequent loss of controllability of the airplane.

DATES: We must receive comments on this proposed AD by September 24, 
2004.

ADDRESSES: Use one of the following addresses to submit comments on 
this proposed AD.
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility, U.S. Department of 
Transportation, 400 Seventh Street SW., Nassif Building, room PL-401, 
Washington, DC 20590.
     By fax: (202) 493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street SW., Washington, DC, between 9 a.m. 
and 5 p.m., Monday through Friday, except Federal holidays.
    For service information identified in this proposed AD, contact 
Boeing Commercial Airplanes, P.O. Box 3707, Seattle, Washington 98124-
2207.
    You can examine the contents of this AD docket on the Internet at 
http://dms.dot.gov, or at the Docket Management Facility, U.S. 
Department of Transportation, 400 Seventh Street SW., room PL-401, on 
the plaza level of the Nassif Building, Washington, DC.

FOR FURTHER INFORMATION CONTACT: Kenneth Frey, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington 98055-
4056; telephone (425) 917-6468; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Docket Management System (DMS)

    The FAA has implemented new procedures for maintaining AD dockets 
electronically. As of May 17, 2004, new AD actions are posted on DMS 
and assigned a docket number. We track each action and assign a 
corresponding directorate identifier. The DMS AD docket number is in 
the form ``Docket No. FAA-2004-99999.'' The Transport Airplane 
Directorate identifier is in the form ``Directorate Identifier 2004-NM-
999-AD.'' Each DMS AD docket also lists the directorate identifier 
(``Old Docket Number'') as a cross-reference for searching purposes.

Comments Invited

    We invite you to submit any written relevant data, views, or 
arguments regarding this proposed AD. Send your comments to an address 
listed under ADDRESSES. Include ``Docket No. FAA-2004-18814; 
Directorate Identifier 2003-NM-286-AD'' in the subject line of your 
comments. We specifically invite comments on the overall regulatory, 
economic, environmental, and energy aspects of the proposed AD. We will 
consider all comments submitted by the closing date and may amend the 
proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed AD. Using the search function of 
that website, anyone can find and read the comments in any of our 
dockets, including the name of the individual who sent the comment (or 
signed the comment on behalf of an association, business, labor union, 
etc.). You can review DOT's complete Privacy Act Statement in the 
Federal Register published on April 11, 2000 (65 FR 19477-78), or you 
can visit http://dms.dot.gov.
    We are reviewing the writing style we currently use in regulatory 
documents. We are interested in your comments on whether the style of 
this document is clear, and your suggestions to improve the clarity of 
our communications that affect you. You can get more information about 
plain language at http://www.faa.gov/language and http://www.plainlanguage.gov.

Examining the Docket

    You can examine the AD docket on the Internet at http://dms.dot.gov, or in person at the Docket Management Facility office 
between 9 a.m. and 5 p.m., Monday through Friday, except Federal 
holidays. The Docket Management Facility office (telephone (800) 647-
5227) is located on the plaza level of the Nassif Building at the DOT 
street address stated in the ADDRESSES section. Comments will be 
available in the AD docket shortly after the DMS receives them.

Discussion

    We have received several reports indicating loose jam nuts and/or 
thread wear at the rod ends on the elevator tab control rod assembly on 
certain Boeing Model 737-100, -200, -200C, -300, -400, and -500 series 
airplanes. If the jam nuts of the elevator tab control rod are not 
properly torqued, the control rod ends can loosen and the threads at 
the rod end can become worn, causing increased freeplay in the tab 
control loop. Airframe vibration can occur if there is sufficient 
freeplay. Additionally, if both control rods on one side of the 
airplane loosen, significant damage can be done to the elevator tab, 
elevator, and horizontal stabilizer. Excessive freeplay in the elevator 
tab control mechanism, if not found and

[[Page 48425]]

fixed, could result in elevator tab flutter and consequent loss of 
controllability of the airplane.

Related AD

    On April 30, 2001, we issued AD 2001-09-51, amendment 39-12251 (66 
FR 31141, June 11, 2001). That AD is applicable to certain Boeing Model 
737-600, -700, -700C, and -800 series airplanes. That AD requires 
inspection of the small jam nut on the elevator tab control rods to 
detect inspection putty and to determine its condition; a torque check 
of the small and large jam nuts on the tab control rod, if necessary; 
and corrective actions, as applicable. For certain airplanes, that AD 
also requires a one-time inspection for torque of the small and large 
jam nuts on the tab control rods; and corrective actions, as 
applicable.

Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 737-
27A1266, dated September 18, 2003, which describes procedures for a 
one-time inspection of the elevator tab control rod assemblies for 
discrepancies, which includes the following, as specified in Part I of 
the Accomplishment Instructions of the service bulletin:
     Inspect for missing or damaged inspection putty.
     Inspect for binding of the control rod.
     Inspect for inadequate clearance between the rod end 
bearing and the clevis of the tab mast fitting; damage to the control 
rod, tab mast fitting, or tab control mechanism clevises.
     Inspect for damage to the elevator tab control rod 
assemblies and/or damage to the surrounding structure.
    The service bulletin also describes procedures for related 
corrective action, which includes the following, as specified in Part 
II of the Accomplishment Instructions of the service bulletin:
     Adjust the control rod.
     Adjust the space between the rod and bearing to provide 
adequate clearance.
     Tighten the jam nuts until correct torque is obtained.
     Replace damaged components with new components.
     Realign the rod ends.
    The service bulletin also describes procedures for operational 
tests and a flight test, if necessary, after the corrective action is 
done. Affected airplanes are separated into Groups 1, 2, and 3, and the 
Accomplishment Instructions of the service bulletin provide the 
inspection/corrective action procedures for each group.
    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

FAA's Determination and Requirements of the Proposed AD

    We have evaluated all pertinent information and identified an 
unsafe condition that is likely to exist or develop on other airplanes 
of this same type design. The proposed AD would require you to perform 
the actions using the service bulletin described previously, except as 
discussed under ``Differences Between the Proposed AD and the Service 
Bulletin.''

Differences Between the Proposed AD and the Service Bulletin

    The service bulletin recommends doing a one-time inspection of the 
elevator tab control rod assemblies. However, we have determined that a 
one-time inspection would not address the identified unsafe condition, 
which could occur again after the one-time inspection is done. 
Therefore, in conjunction with the manufacturer, we have determined 
that this proposed AD would require repetitive inspections at intervals 
not to exceed 4,500 flight cycles or 6,000 flight hours, whichever is 
first. We find that doing repetitive inspections allows affected 
airplanes to continue to operate without compromising safety.
    The service bulletin refers only to an inspection for discrepancies 
of the elevator tab control rod assemblies and/or damage to the 
surrounding structure. We have determined that the inspection should be 
described as a ``detailed inspection.'' Note 1 in this proposed AD 
defines this type of inspection.

Costs of Compliance

    This proposed AD would affect about 1,078 airplanes of U.S. 
registry and 2,878 airplanes worldwide. The proposed inspection would 
take about 2 work hours per airplane, at an average labor rate of $65 
per work hour. Based on these figures, the estimated cost of the 
proposed AD for U.S. operators is $140,140, or $130 per airplane, per 
inspection cycle.

Regulatory Findings

    We have determined that this proposed AD would not have federalism 
implications under Executive Order 13132. This proposed AD 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the FAA proposes to amend 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. The FAA amends Sec.  39.13 by adding the following new 
airworthiness directive (AD):

Boeing: Docket No. FAA-2004-18814; Directorate Identifier 2003-NM-
286-AD.

Comments Due Date

    (a) The Federal Aviation Administration (FAA) must receive 
comments on this AD action by September 24, 2004.

Affected ADs

    (b) None.

Applicability

    (c) This AD applies to all Model 737-100, -200, -200C, -300, -
400, and -500 series airplanes; certificated in any category.

Unsafe Condition

    (d) This AD was prompted by reports indicating loose jam nuts 
and/or thread wear at the rod ends on the elevator tab control rod 
assembly. We are issuing this AD to find and fix excessive freeplay 
in the elevator tab control mechanism, which could result in 
elevator tab flutter and consequent loss of controllability of the 
airplane.

Compliance

    (e) You are responsible for having the actions required by this 
AD performed within the compliance times specified, unless the 
actions have already been done.

Repetitive Inspections

    (f) Within 4,500 flight cycles or 6,000 flight hours after the 
effective date of this AD,

[[Page 48426]]

whichever is first: Do a detailed inspection for discrepancies of 
the elevator tab control rod assemblies and/or damage to the 
surrounding structure, including corrective action, by doing all the 
actions in the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-27A1266, dated September 18, 2003. Do any related 
corrective action before further flight, in accordance with the 
service bulletin. Repeat the inspection thereafter at intervals not 
to exceed 4,500 flight cycles or 6,000 flight hours, whichever is 
first.

    Note 1: For the purposes of this AD, a detailed inspection is: 
``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.''

Alternative Methods of Compliance (AMOCs)

    (g) The Manager, Seattle Aircraft Certification Office, FAA, has 
the authority to approve AMOCs for this AD, if requested in 
accordance with the procedures found in 14 CFR 39.19.

    Issued in Renton, Washington, on August 3, 2004.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 04-18221 Filed 8-9-04; 8:45 am]
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