[Federal Register Volume 67, Number 221 (Friday, November 15, 2002)]
[Proposed Rules]
[Pages 69157-69160]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 02-29005]



[[Page 69157]]

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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2002-NM-240-AD]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737-600, -700, -700C, -
800, and -900 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the adoption of a new airworthiness 
directive (AD) that is applicable to certain Boeing Model 737-600, -
700, -700C, -800, and -900 series airplanes. This proposal would 
require installing speedbrake limitation placards in the flight 
compartment; and revising the Limitations Section of the Airplane 
Flight Manual to ensure the flightcrew is advised not to extend the 
speedbrake lever beyond the flight detent. For certain airplanes, this 
proposal would require modifying the elevator and elevator tab 
assembly. This action is necessary to prevent severe vibration of the 
elevator and elevator tab assembly, which could result in severe damage 
to the horizontal stabilizer, followed by possible loss of the elevator 
tab and consequent loss of controllability of the airplane. This action 
is intended to address the identified unsafe condition.

DATES: Comments must be received by December 30, 2002.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2002-NM-240-AD, 1601 Lind Avenue, SW., 
Renton, Washington 98055-4056. Comments may be inspected at this 
location between 9 a.m. and 3 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: 
[email protected]. Comments sent via fax or the Internet must 
contain ``Docket No. 2002-NM-240-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 H. 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:
    [sbull] 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.
    [sbull] For each issue, state what specific change to the proposed 
AD is being requested.
    [sbull] 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 2002-NM-240-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. 2002-NM-240-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The FAA has received several reports of excessive in-flight 
vibrations of the elevator and elevator tab on certain Boeing Model 
737-600, -700, -700C, -800, and -900 series airplanes. The FAA 
responded to these reports by issuing several rulemaking actions 
(listed below). These actions were identified as interim action until a 
modification for the elevator and elevator tab assemblies was 
developed, approved, and available. The intent of such a modification 
is to reduce the reliance on inspections to assure the continued 
airworthiness of the affected airplanes and to relieve certain 
significant operational restrictions imposed on the affected airplanes. 
The manufacturer now has developed such a modification, and the FAA has 
determined that further rulemaking action is indeed necessary; this 
proposed AD follows from that determination.
    The elevator and elevator tab are susceptible to excessive 
vibration and, under certain conditions, limit-cycle flutter. These 
vibration events have been attributed to loose or missing components, 
excessive wear, or excessive freeplay of the tab. Elevator tab 
vibrations following deployment of the speedbrakes can result in wear 
to the elevator tab hinges and components of the elevator tab control 
system. Such wear can cause the elevator tab assemblies to become 
loose. Continued exposure to spoiler buffeting can cause excessive wear 
to the elevator tab components. Continued operation of these airplanes 
in such conditions could result in severe damage to the horizontal 
stabilizer, followed by possible loss of the elevator tab and 
consequent loss of controllability of the airplane.

Terminating Action for Related Rulemaking

    The requirements of this AD are intended to be terminating action 
for the following ADs:
    [sbull] AD 99-15-09, amendment 39-11229 (64 FR 40514, July 27, 
1999), was issued on July 13, 1999, and is applicable to certain Boeing 
Model 737-600 series airplanes. That AD requires revising the Airplane 
Flight Manual (AFM) to prohibit operation of the airplane under certain 
conditions; repetitive inspections of the tab mast fittings of the 
elevator tab assemblies to detect cracking; an elevator tab freeplay 
check; and corrective actions, if necessary. That AD also requires 
installing an additional fastener on the elevator tab mast fitting, 
which terminates the AFM revision and

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extends certain repetitive inspections. That AD also requires 
replacement of the elevator tab mast fitting with a new, improved 
fitting, which terminates the required actions.
    [sbull] AD 99-18-01, amendment 39-11267 (64 FR 46259, August 25, 
1999), was issued on August 18, 1999, and is applicable to certain 
Boeing Model 737-700 and -800 series airplanes. That AD supersedes AD 
99-13-51, amendment 39-11213 (64 FR 34976, June 30, 1999), to continue 
to require revising the AFM to prohibit operation of the airplane under 
certain conditions; repetitive inspections of the tab mast fitting of 
the elevator tab assemblies to detect cracking; an elevator tab 
freeplay check; and corrective actions, if necessary. AD 99-18-01 also 
continues to provide for optional terminating action only for certain 
repetitive inspections; and installing an additional fastener on the 
elevator tab mast fitting, which terminates the AFM revision and 
extends certain repetitive inspection intervals.
    [sbull] AD 2001-08-09, amendment 39-12186 (66 FR 20194, April 20, 
2001), was issued on April 13, 2001, and is applicable to certain 
Boeing Model 737-600, -700, -800, and -700C series airplanes. That AD 
supersedes AD 2001-04-08, amendment 39-12127 (66 FR 13229, March 5, 
2001), to continue to require initial and repetitive inspections of the 
elevator tab assembly to detect any damage or discrepancy; and 
corrective actions, if necessary. AD 2001-08-09 also clarifies the 
applicability and certain requirements of AD 2001-04-08.
    [sbull] AD 2001-09-51, amendment 39-12251 (66 FR 31141, June 11, 
2001), was issued on May 25, 2001, and 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.
    [sbull] AD 2001-12-51, amendment 39-12294 (66 FR 34098, June 27, 
2001), was issued on June 20, 2001, and is applicable to all Boeing 
Model 737-800 series airplanes. That AD requires revising the AFM to 
prohibit operating the airplane at speeds in excess of 300 knots 
indicated airspeed (KIAS) with speedbrakes extended. That AD also 
provides for optional terminating action for the AFM revision.
    [sbull] AD 2001-14-05, amendment 39-12315 (66 FR 36145, July 12, 
2001), was issued on July 2, 2001, and is applicable to all Boeing 
Model 737-600,-700,-700C, and-800 series airplanes. That AD prohibits 
installation of repairs of the elevator tab using previously approved 
repair procedures.
    [sbull] AD 2002-08-52, amendment 39-12727 (67 FR 20626, April 26, 
2002), was issued on April 19, 2002, and is applicable to all Boeing 
Model 737-600,-700, and-700C series airplanes. That AD requires 
revising the AFM to ensure that the flightcrew is advised of the 
potential hazard associated with extending the speedbrakes at speeds in 
excess of 300 KIAS. That AD also provides for optional modification or 
retrofit of the elevator tab assembly.
    [sbull] AD 2002-08-20, amendment 39-12732 (67 FR 20628, April 26, 
2002), was issued on April 19, 2002, and is applicable to all Boeing 
Model 737-600,-700,-700C, and 800 series airplanes. That AD requires 
inspecting the airplane following any suspected limit cycle oscillation 
(LCO) of the elevator tab; and revising the AFM to limit airspeeds 
under certain conditions and to provide the flight crew with 
information regarding elevator tab LCO. That AD also requires 
repetitive cleaning of the elevator tab and a one-time cleaning of the 
elevator balance bays. That AD provides for the option to repetitively 
clean the elevator tab and balance bays following every deicing/anti-
icing of the horizontal stabilizer, which would temporarily allow 
airspeeds exceeding those limited by the AFM revision. For certain 
airplanes, that AD requires trimming the elevator balance panel seals, 
which will terminate the optional repetitive cleaning procedures for 
the balance bays.

Related AD

    AD 2001-23-01, amendment 39-12498 (66 FR 56989, November 14, 2001), 
was issued on November 5, 2001, and is applicable to certain Boeing 
Model 737-600,-700, and-800 series airplanes. That AD supersedes AD 
2001-06-08, amendment 39-12155 (66 FR 16116, March 23, 2001), to 
continue to require repetitive inspections of certain elevator hinge 
plates, and corrective action, if necessary. That AD also requires 
accomplishment of the previously optional replacement of the elevator 
hinge plates with new, improved hinge plates, as terminating action for 
the repetitive inspections. The requirements of AD 2001-23-01 are 
prerequisite to the requirements contained in the proposed AD.

Explanation of Relevant Service Information

    We have reviewed and approved Boeing Alert Service Bulletin 737-
11A1109, dated March 28, 2002, which, for certain airplanes, describes 
procedures for installation of a speedbrake limitation marker (placard) 
on the P1-1 and P3-3 panel assemblies. For Group 1 airplanes, the 
placard is centered directly over the Captain's and the First Officer's 
clocks; for Group 2 airplanes, the placard is centered directly over 
the Captain's clock, and directly under the First Officer's clock.
    We also have reviewed and approved Boeing Alert Service Bulletin 
737-55A1080, dated September 19, 2002, which describes procedures for 
modification of the elevator and elevator tab assembly. The 
modification includes installation of a new clevis fitting and a new 
tab mechanism on the horizontal stabilizer and, for certain airplanes, 
examination of the hinge plates on the stabilizer trailing edge to make 
sure the specified hinges are installed. The modification also includes 
changes to the seals in the balance bays and installation of new 
elevators and tab assemblies, followed by adjustments and tests of the 
new installation.
    Accomplishment of the actions specified in the service bulletins is 
intended to adequately address the identified unsafe condition.

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 require accomplishment of the actions specified in 
the service bulletins described previously, except as discussed below.

Differences Between Proposed AD and Service Information

Boeing Alert Service Bulletin 737-11A1109

    Although the service bulletin recommends accomplishing the 
installation of the placards ``at the first maintenance period when 
material and manpower are available,'' we have determined that such an 
imprecise compliance time would not address the identified unsafe 
condition in a timely manner. In developing an appropriate compliance 
time for the installation in this proposed AD, we considered not only 
the manufacturer's recommendation, but the degree of

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urgency associated with addressing the subject unsafe condition, the 
average utilization of the affected fleet, and the time necessary to 
perform the modifications. In light of all of these factors, we find a 
compliance time of 90 days for completing the required installation to 
be warranted, in that it represents an appropriate interval of time 
allowable for affected airplanes to continue to operate without 
compromising safety.
    Additionally, the service bulletin does not recommend a 
corresponding change to the Limitations Section of the AFM to reflect 
the speedbrake limitation on the placards; however, this proposed AD 
requires that, for certain airplanes, such a change be made within 90 
days to instruct the flightcrew not to extend the speedbrake lever 
beyond the flight detent in flight.

Boeing Alert Service Bulletin 737-55A1080

    The service bulletin specifies accomplishment of certain actions 
required by this proposed AD in accordance with either the Boeing 737 
Airplane Maintenance Manual (AMM) or an ``operator's equivalent 
procedure.'' However, this proposed AD requires that the actions 
required by those paragraphs be accomplished in accordance with the 
procedures specified in the Boeing 737 AMM. ``Operators' equivalent 
procedures'' may be used only if approved as an alternative method of 
compliance in accordance with paragraph (e) of this AD.

Cost Impact

    There are approximately 1,174 airplanes of the affected design in 
the worldwide fleet. We estimate that 550 airplanes of U.S. registry 
would be affected by this proposed AD.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed placard installation, at an average labor rate of $60 per 
work hour. Based on these figures, the cost impact of the proposed 
installation on U.S. operators is estimated to be $33,000, or $60 per 
airplane.
    It would take approximately 1 work hour per airplane to accomplish 
the proposed AFM revision, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the proposed revision 
on U.S. operators is estimated to be $33,000, or $60 per airplane.
    It would take approximately 88 work hours per airplane to 
accomplish the proposed modification of the elevator and elevator tab 
assembly, at an average labor rate of $60 per work hour. The FAA has 
been advised by Boeing that the manufacturer will provide parts for the 
elevator/tab retrofit, including shipping, at no cost to operators. The 
manufacturer will have operators ``exchange'' their existing parts for 
new parts to support the retrofit program. Based on this information, 
the cost impact of the proposed modification on U.S. operators is 
estimated to be $2,904,000, or $5,280 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 adding the following new 
airworthiness directive:

Boeing: Docket 2002-NM-240-AD.

    Applicability: Model 737-600,-700,-700C,-800, and-900 series 
airplanes; line numbers 1 through 1174 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 (e) 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 severe vibration of the elevator and elevator tab 
assembly, which could result in severe damage to the horizontal 
stabilizer, followed by possible loss of the elevator tab and 
consequent loss of controllability of the airplane, accomplish the 
following:

Airplane Flight Manual (AFM) Revision/Placard Installation

    (a) For Model 737-600,-700,-700C,-800, and-900 series airplanes 
having line numbers 1 through 1043 inclusive: Within 90 days after 
the effective date of this AD, do the actions specified in 
paragraphs (a)(1) and (a)(2) of this AD.
    (1) Install a speedbrake limitation placard on the P1-1 and P3-3 
panel assemblies per Figure 1 or Figure 2, as applicable, of 
paragraph 3.B., ``Work Instructions,'' of the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-11A1109, dated 
March 28, 2002.
    (2) Revise the Limitations Section of the FAA-approved AFM to 
include the following statement (this may be accomplished by 
inserting a copy of this AD in the AFM): ``Do not extend the 
speedbrake lever beyond the flight detent in flight.''

Modification

    (b) For Model 737-600,-700,-700C, and-800 series airplanes 
having line numbers 1 through 1174 inclusive: Before the 
accumulation of 18,000 total flight cycles, or within 2 years after 
the effective date of this AD, whichever occurs first, modify the 
elevator and elevator tab assemblies (including installation of a 
new clevis fitting

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and a new tab mechanism on the horizontal stabilizer and, for 
certain airplanes, examination of the hinge plates on the stabilizer 
trailing edge to make sure the specified hinges are installed; 
changes to the seals in the balance bays; and installation of new 
elevators and tab assemblies, followed by adjustments and tests of 
the new installation), per the Accomplishment Instructions of Boeing 
Alert Service Bulletin 737-55A1080, dated September 19, 2002.
    (c) Accomplishment of the modification required by paragraph (b) 
of this AD terminates the actions required by the ADs specified in 
the table below.

------------------------------------------------------------------------
                                                              Amendment
                           AD No.                                No.
------------------------------------------------------------------------
AD 99-15-09................................................     39-11229
AD 99-18-01................................................     39-11267
AD 2001-08-09..............................................     39-12186
AD 2001-09-51..............................................     39-12251
AD 2001-12-51..............................................     39-12294
AD 2001-14-05..............................................     39-12315
AD 2002-08-52..............................................     39-12727
AD 2002-08-20..............................................     39-12732
------------------------------------------------------------------------

Operator's Equivalent Procedure

    (d) If the Accomplishment Instructions of Boeing Alert Service 
Bulletin 737-55A1080, dated September 19, 2002, specify that the 
actions may be accomplished in accordance with an operator's 
``equivalent procedure:'' The actions must be accomplished per the 
applicable chapter of the Boeing 737 Airplane Maintenance Manual 
specified in the alert service bulletin.

Alternative Methods of Compliance

    (e) 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 Aircraft Certification 
Office (ACO), FAA. 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 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Seattle ACO.

Special Flight Permit

    (f) Special flight permits may be issued in accordance with 
sections Sec.  Sec.  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 November 8, 2002.
Ali Bahrami,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-29005 Filed 11-14-02; 8:45 am]
BILLING CODE 4910-13-P