AD Amdt-39-12940

[Federal Register Volume 67, Number 215 (Wednesday, November 6, 2002)]
[Rules and Regulations]
[Pages 67518-67520]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 02-28111]


-----------------------------------------------------------------------

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 2001-NM-251-AD; Amendment 39-12940; AD 2002-20-07 R1]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule; request for comments.

-----------------------------------------------------------------------

SUMMARY: This amendment revises an existing airworthiness directive 
(AD), applicable to all Boeing Model 737 series airplanes, that 
currently requires installation of a new rudder control system and 
changes to the adjacent systems to accommodate that new rudder control 
system. That amendment would have superseded seven existing ADs; 
however, this new amendment removes any reference to superseding four 
of those seven ADs. This new amendment is prompted by an FAA 
determination that the requirements of those four ADs must remain in 
effect until installation of the new rudder control system and 
corresponding changes to the adjacent systems. The actions specified in 
this AD are intended to prevent an uncommanded rudder hardover event 
and consequent loss of control of the airplane due to inherent failure 
modes, including single-jam modes, and certain latent failures or jams 
combined with a second failure or jam.

DATES: Effective November 12, 2002.
    Comments for inclusion in the Rules Docket must be received on or 
before January 6, 2003.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114, 
Attention: Rules Docket No. 2001-NM-251-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: 
<a href="/cdn-cgi/l/email-protection#0930246867642460687b6a6664646c677d496f6868276e667f"><span class="__cf_email__" data-cfemail="d2ebffb3bcbfffbbb3a0b1bdbfbfb7bca692b4b3b3fcb5bda4">[email&#160;protected]</span></a>. Comments sent via fax or the Internet must 
contain ``Docket No. 2001-NM-251-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 information concerning this amendment may be obtained from or 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington 98055-4056.

FOR FURTHER INFORMATION CONTACT: Kenneth W. Frey, Aerospace Engineer, 
Systems and Equipment Branch, ANM-130S, FAA, Seattle Aircraft 
Certification Office, 1601 Lind Avenue, SW., Renton, Washington; 
telephone (425) 227-2673; fax (425) 227-1181.

SUPPLEMENTARY INFORMATION: On September 27, 2002, the FAA issued AD 
2002-20-07, amendment 39-12903 (67 FR 62341, October 7, 2002), 
applicable to all Boeing Model 737 series airplanes, to require 
installation of a new rudder control system and changes to the adjacent 
systems to accommodate that new rudder control system. That action was 
prompted by FAA determinations that the existing system design 
architecture is unsafe due to inherent failure modes, including single-
jam modes and certain latent failures or jams, which, when combined 
with a second failure or jam, could cause an uncommanded rudder 
hardover event and consequent loss of control of the airplane. 
Additionally, the current rudder operational procedure is not effective 
throughout the entire flight envelope. The actions required by that AD 
are intended to prevent the identified unsafe condition.

Actions Since Issuance of Previous Rule

    AD 2002-20-07 would have superseded seven existing ADs. However, 
since the issuance of that AD, the FAA finds that only three of those 
ADs should have been superseded. By superseding the other four ADs, we 
inadvertently eliminated the requirements of those four ADs as of the 
effective date of AD 2002-20-07, instead of upon accomplishment of the 
actions required by that AD. We find that retaining the requirements of 
those four ADs is necessary to maintain the current level of safety 
until the requirements of this new AD are accomplished. This finding 
does not impose any additional burden on any operator because the 
requirements of those four ADs already exist.
    The requirements of the following four ADs remain in effect until 
installation of the new rudder control system and corresponding changes 
to the adjacent systems:
    [sbull] AD 97-09-15 R1, amendment 39-10912 (63 FR 64857, November 
24, 1998), applies to all Boeing Model 737-100, -200, -300, -400, and -
500 series airplanes. That AD requires a one-time inspection of the 
engage solenoid valve of the yaw damper on the rudder power control 
unit (PCU) to determine the part number (P/N) of the valve, and 
replacement of certain valves with specified P/Ns if necessary. 
Retaining this requirement will ensure that the appropriate engage 
solenoid valve is installed on the rudder PCU of all affected airplanes 
until accomplishment of this new AD.
    [sbull] AD 97-14-04, amendment 39-10061 (62 FR 35068, June 30, 
1997), applies to all Boeing Model 737-100, -200, -300, -400, and -500 
series airplanes. That AD requires tests of the main rudder PCU to 
detect excessive internal leakage of hydraulic fluid, stalling, or 
reversal, and to verify proper operation of the PCU; and replacement of 
the PCU with a unit having a different part number if necessary. That 
AD also requires replacement of the PCU and the vernier control rod 
bolts with newly designed units, leak tests of the PCU, and replacement 
of the PCU with a serviceable or newly designed unit if necessary. 
Retaining these requirements will ensure that the appropriate vernier 
control rod bolts and main rudder PCU

[[Page 67519]]

are installed and properly maintained until accomplishment of this new 
AD.
    [sbull] AD 99-11-05, amendment 39-11175 (64 FR 27905, May 24, 
1999). A correction of that AD was published in the Federal Register on 
December 13, 1999 (64 FR 69392). That AD applies to all Boeing Model 
737 series airplanes, and requires repetitive displacement tests of the 
secondary slide in the dual concentric servo valve of the PCU for the 
rudder, and replacement of the valve assembly with a modified valve 
assembly if necessary. Retaining these requirements will ensure that 
the repetitive displacement tests will continue to be performed until 
accomplishment of this new AD.
    The AD number and Federal Register citation for AD 99-11-05 
appeared incorrectly in AD 2002-20-07. This information is specified 
correctly in the preceding paragraph.
    [sbull] AD 2000-22-02, amendment 39-11948 (65 FR 64134, October 26, 
2000). A correction of that AD was published in the Federal Register on 
November 16, 2000 (65 FR 69239), as AD 2000-22-02 R1, which applies to 
all Boeing Model 737 series airplanes. Those ADs require revising an 
FAA-approved Airplane Flight Manual (AFM) procedure to simplify the 
instructions for correcting a jammed or restricted flight control 
condition. Retaining this AFM change will ensure that the flightcrew 
continues to be advised of the procedures necessary to address a 
condition involving a jammed or restricted rudder until accomplishment 
of this new AD.

Explanation of Requirements of Rule

    Since an unsafe condition has been identified that is likely to 
exist or develop on other airplanes of this same type design, this new 
AD revises AD 2002-20-07, which would have superseded seven existing 
ADs. This new AD continues to require installation of a new rudder 
control system and changes to the adjacent systems to accommodate that 
new rudder control system. This new AD also removes any reference to 
superseding four of those seven existing ADs.
    Paragraph (b) of this AD specifies that installation of a new 
rudder control system and changes to the adjacent systems to 
accommodate that new rudder control system terminates the requirements 
of ADs 97-09-15 R1, 97-14-04, 99-11-05, and 2000-22-02 R1.

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.
    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 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 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 2001-NM-251-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, 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 removing amendment 39-9199 (60 FR 
18981, April 14, 1995); amendment 39-9954 (62 FR 9679, March 4, 1997); 
and amendment 39-10283 (63 FR 1903, January 13, 1998); and by adding a 
new airworthiness directive (AD), amendment 39-12940, to read as 
follows:

2002-20-07 R1 Boeing: Amendment 39-12940. Docket 2001-NM-251-AD. 
Revises AD 2002-20-07, Amendment 39-12903. Supersedes AD 95-06-53, 
Amendment 39-9199; AD 97-05-10, Amendment 39-9954; and AD 98-02-01, 
Amendment 39-10283.

    Applicability: All Model 737 series airplanes, 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

[[Page 67520]]

requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (c)(1) 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 an uncommanded rudder hardover event and consequent 
loss of control of the airplane due to inherent failure modes, 
including single-jam modes, and certain latent failures or jams 
combined with a second failure or jam; accomplish the following:

Installation

    (a) Within 6 years after November 12, 2002 (the effective date 
of AD 2002-20-07, amendment 39-12903), do the actions required by 
paragraphs (a)(1) and (a)(2) of this AD, in accordance with a method 
approved by the Manager, Seattle Aircraft Certification Office 
(ACO), FAA.
    (1) Install a new rudder control system that includes new 
components such as an aft torque tube, hydraulic actuators, and 
associated control rods, and additional wiring throughout the 
airplane to support failure annunciation of the rudder control 
system in the flight deck. The system also must incorporate two 
separate inputs, each with an override mechanism, to two separate 
servo valves on the main rudder power control unit (PCU); and an 
input to the standby PCU that also will include an override 
mechanism.
    (2) Make applicable changes to the adjacent systems to 
accommodate the new rudder control system.

Terminating Action

    (b) Accomplishment of the actions required by paragraph (a) of 
this AD constitutes terminating action for the requirements of AD 
97-09-15 R1, amendment 39-10912; AD 97-14-04, amendment 39-10061; AD 
99-11-05, amendment 39-11175; and AD 2000-22-02 R1, amendment 39-
11948.

Alternative Methods of Compliance

    (c)(1) 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.
    (2) Alternative methods of compliance, approved previously in 
accordance with the ADs listed in the following table, are not 
considered to be approved as alternative methods of compliance with 
this AD:

                      Table--List of Superseded ADs
------------------------------------------------------------------------
                         AD No.                            Amendment No.
------------------------------------------------------------------------
95-06-53................................................         39-9199
97-05-10................................................         39-9954
98-02-01................................................        39-10283
------------------------------------------------------------------------


    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 Permits

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

Effective Date

    (e) This amendment becomes effective on November 12, 2002.

    Issued in Renton, Washington, on October 30, 2002.
Vi L. Lipski,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 02-28111 Filed 11-5-02; 8:45 am]
BILLING CODE 4910-13-P