[Federal Register Volume 72, Number 21 (Thursday, February 1, 2007)]
[Rules and Regulations]
[Pages 4625-4633]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E7-1496]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-26323; Directorate Identifier 2006-NM-150-AD; 
Amendment 39-14918; AD 2007-03-07]
RIN 2120-AA64


Airworthiness Directives; Boeing Model 737 Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Final rule; request for comments.

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SUMMARY: The FAA is superseding an existing airworthiness directive 
(AD) that applies to all Boeing Model 737 airplanes. The existing AD 
currently requires installation of a new rudder control system and 
changes to the adjacent systems to accommodate that new rudder control 
system. For certain airplanes, this new AD adds, among other actions, 
repetitive tests of the force fight monitor of the main rudder power 
control unit (PCU), repetitive tests of the standby hydraulic actuation 
system, and corrective action; as applicable. For those airplanes, this 
new AD also adds, among other actions, replacement of both input 
control rods of the main rudder PCU and the input control rod of the 
standby rudder PCU with new input control rods, as applicable, which 
ends the repetitive tests. For certain other airplanes, this new AD 
adds installation of an enhanced rudder control system in accordance 
with new service information. This AD results from a report of a 
fractured rod end of an input control rod of the main rudder PCU and a 
subsequent report of a fractured rod end of the input control rod of 
the standby rudder PCU. We are issuing this AD to prevent failure of 
one of the two input control rods of the main rudder PCU, which, under 
certain conditions, could result in reduced controllability of the 
airplane; and to prevent failure of any combination of two input 
control rods of the main rudder PCU and/or standby rudder PCU, which 
could cause an uncommanded rudder hardover event and result in loss of 
control of the airplane.

DATES: This AD becomes effective February 16, 2007.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the AD as of February 16, 
2007.
    We must receive any comments on this AD by April 2, 2007.

ADDRESSES: Use one of the following addresses to submit comments on 
this 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.
     Fax: (202) 493-2251.

[[Page 4626]]

     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.
    Contact Boeing Commercial Airplanes, P.O. Box 3707, Seattle, 
Washington 98124-2207, for service information identified in this AD.
    You may examine the contents of the AD docket on the Internet at 
http://dms.dot.gov, or in person at the Docket Management Facility, 
U.S. Department of Transportation, 400 Seventh Street, SW., Room PL-
401, Washington, DC. This docket number is FAA-2006-26323; the 
directorate identifier for this docket is 2006-NM-150-AD.

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 98057-
3356; telephone (425) 917-6468; fax (425) 917-6590.

SUPPLEMENTARY INFORMATION:

Discussion

    The FAA issued a notice of proposed rulemaking (NPRM) to amend 14 
CFR part 39 to include an AD that supersedes AD 2002-20-07 R1, 
amendment 39-12940 (67 FR 67518, November 6, 2002). The existing AD 
applies to all Boeing Model 737 airplanes. That NPRM was published in 
the Federal Register on November 15, 2006 (71 FR 66474). That NPRM 
proposed to continue to require installation of a new rudder control 
system and changes to the adjacent systems to accommodate that new 
rudder control system. For certain airplanes, that NPRM proposed to 
add, among other actions, repetitive tests of the force fight monitor 
of the main rudder power control unit (PCU), repetitive tests of the 
standby hydraulic actuation system, and corrective action; as 
applicable. For those airplanes, that NPRM also proposed to add, among 
other actions, replacement of both input control rods of the main 
rudder PCU and the input control rod of the standby rudder PCU with new 
input control rods, as applicable, which would end the repetitive 
tests. For certain other airplanes, that NPRM proposed to add 
installation of an enhanced rudder control system in accordance with 
new service information.

Actions Since NPRM Was Issued

    Since we issued the NPRM, we have received a report of a fractured 
rod end on the input control rod of the standby rudder PCU on a Model 
737-700 series airplane. This condition was discovered during 
accomplishment of an operational test of the standby hydraulic 
actuation system in accordance with Boeing Alert Service Bulletin 737-
27A1280, dated May 25, 2006 (one of the actions specified in the NPRM). 
Investigation revealed that, although the input control rod had an 
existing crack of significant size, it ultimately fractured due to 
fatigue damage. Fatigue damage is caused by repetitive forces being 
applied (i.e., cyclic loading).
    This finding of fatigue damage is not consistent with the results 
of our investigation that led to actions specified in the NPRM. The 
actions and compliance times specified in the NPRM were based on our 
finding that, while the input control rod may have been cracked during 
assembly, no significant loading was present to further degrade the 
integrity of the input control rod over time, causing it to fracture.
    Therefore, we have determined that, for certain Model 737-600, -
700, -700C, -800, and -900 series airplanes on which the suspect input 
control rod of the standby rudder PCU was installed during production, 
the compliance times for the following actions in the NPRM will not 
detect and correct failure of the input control rod of the standby 
rudder PCU in a timely manner:
     The initial compliance time and repetitive intervals for 
the operational tests specified in paragraph (g)(1), and
     The threshold for the replacement of the input control rod 
of the standby rudder PCU specified in paragraph (g)(3).
    Failure of one of the two input control rods of main rudder PCU, 
under certain conditions, could result in reduced controllability of 
the airplane; and failure of any combination of two input control rods 
of the main rudder PCU and/or standby rudder PCU could cause an 
uncommanded rudder hardover event and result in loss of control of the 
airplane.

Relevant Service Information

    As discussed in the ``Relevant Service Information'' section of the 
NPRM, we have reviewed the following service information:

                                          Relevant Service Information
----------------------------------------------------------------------------------------------------------------
             Service Bulletin                      Revision level                          Date
----------------------------------------------------------------------------------------------------------------
Boeing Alert Service Bulletin 737-27A1239  Original.....................  January 11, 2001.
Boeing Alert Service Bulletin 737-27A1279  Original.....................  June 20, 2006.
Boeing Alert Service Bulletin 737-27A1280  Original.....................  May 25, 2006.
Boeing Alert Service Bulletin 737-27A1281  Original.....................  June 14, 2006.
Boeing Service Bulletin 737-22-1042......  1............................  April 5, 1985.
Boeing Service Bulletin 737-27A1206......  3............................  December 14, 2000.
Boeing Service Bulletin 737-27-1246,       1............................  February 21, 2002.
 including Appendix A.
Boeing Service Bulletin 737-27-1247......  1............................  July 25, 2002.
Boeing Service Bulletin 737-27-1252......  3............................  May 12, 2006.
Boeing Service Bulletin 737-27-1253......  3............................  May 12, 2006.
Boeing Service Bulletin 737-27-1255......  3............................  May 10, 2006.
Boeing Service Bulletin 737-27-1262......  Original.....................  December 19, 2002.
Boeing Service Bulletin 737-27-1263......  1............................  September 25, 2003.
Boeing Service Bulletin 737-27-1264......  1............................  April 3, 2003.
Boeing Service Bulletin 737-55-1052......  1............................  August 5, 2004.
Boeing 737 Service Bulletin 27-1026......  Original.....................  January 15, 1971.
Smiths Aerospace Actuation Systems         Original.....................  August 28, 2003.
 Service Bulletin 1150-27-05A.
----------------------------------------------------------------------------------------------------------------

    Accomplishing the actions specified in the service information is 
intended to adequately address the unsafe condition.

Comments

    We provided the public the opportunity to submit comments

[[Page 4627]]

regarding the NPRM and have considered the comments that have been 
received.

Support for the NPRM

    The Air Line Pilots Association and Boeing support the NPRM.

Requests To Issue Stand Alone AD

    Delta and Southwest Airlines request that we issue a stand alone AD 
that addresses the control rod issues only instead of superseding AD 
2002-20-07 R1. Delta states that a stand alone AD will minimize the 
amount of revisions to engineering authorizations (EAs). Delta points 
out that a supersedure AD would result in their revising four EAs 
whereas a stand alone AD would result in revising only one EA. 
Southwest Airlines states that a stand alone AD would be more cost 
effective because a supersedure AD results in document revision, record 
keeping, and computer tracking issues.
    We do not agree. As explained in the ``Actions Since Existing AD 
Was Issued'' section of the NPRM, we have received a report of a 
fractured rod end on one of the two input control rods of the main 
rudder PCU on a Model 737-800 series airplane. The incident airplane 
had been modified to comply with the requirements of AD 2002-20-07 R1. 
We determined that accomplishment of the actions required by AD 2002-
20-07 R1 introduces a new unsafe condition (i.e., failure of the input 
control rods of the rudder control system, which, under certain 
conditions, could result in reduced controllability of the airplane 
and/or loss of control of the airplane), and that a substantive change 
to that AD was necessary.
    Our current policy specifies that, whenever a substantive change is 
made to an existing AD that imposes a new burden, we must supersede the 
AD. Substantive changes are those made to any instruction or reference 
that affects the substance of the AD. Substantive changes include part 
numbers, service bulletin and manual references, compliance times, 
applicability, methods of compliance, corrective action, inspection 
requirements, and effective dates. We consider the changes to the 
existing AD to be substantive. This superseding AD is assigned a new 
amendment number and new AD number, and the previous amendment is 
removed from the system. This procedure facilitates the efforts of 
principal maintenance inspectors in tracking ADs and ensuring that 
affected operators have incorporated the most recent changes into their 
maintenance programs.
    With regard to paperwork changes required by affected operators, 
Sec.  121.380(a)(2)(vi) (``Maintenance recording requirements'') of the 
Federal Aviation Regulations (14 CFR 121.380(a)(2)(vi)), requires that 
persons holding an operating certificate and operating under part 121 
of the Federal Aviation Regulations must keep ``The current status of 
applicable airworthiness directives, including the date and methods of 
compliance * * *.'' Whether an existing AD is superseded or a new stand 
alone AD is issued, the new AD is assigned a new AD number. In either 
case, the new AD is identified by its ``new'' AD number. In light of 
this, affected operators updating their maintenance records to indicate 
the current AD status would have to record a new AD number in both 
cases. Further, operators are always given credit for work previously 
performed according to the existing AD by means of the phrase in the 
compliance section of the AD that states, ``* * * unless the actions 
have already been done.'' Therefore, we have determined that a 
supersedure AD is appropriate.

Request To Supersede Other ADs

    If the AD does supersede AD 2002-20-07 R1, Southwest Airlines 
requests that the AD also supersede the following ADs:
     AD 95-06-53, amendment 39-9199 (60 FR 18981, April 14, 
1995);
     AD 97-05-10, amendment 39-9954 (62 FR 9679, March 4, 
1997); and
     AD 98-02-01, amendment 39-10283 (63 FR 1903, January 13, 
1998).
    Southwest Airlines states that these additional ADs were all listed 
in AD 2002-20-07 R1. Southwest Airlines states that if these changes 
are not made, operators will be required to report the status of 
obsolete ADs.
    We do not agree. AD 2002-20-07 R1 revises AD 2002-20-07, amendment 
39-12903 (67 FR 62341, October 7, 2002), and supersedes ADs 95-06-53, 
97-05-10, and 98-02-01. As of November 12, 2002 (the effective date of 
AD 2002-20-07 R1), those ADs were effectively superseded (cancelled) 
and thus no further action is required in regard to those ADs.

Request To Change List of Affected ADs

    Southwest Airlines also requests that AD 97-14-04, amendment 39-
10061 (62 FR 35068, June 30, 1997), be added to the list of ADs in 
Table 1 of the NPRM.
    We agree. Our intent was to retain all requirements of AD 2002-20-
07 R1. AD 97-14-04 was included in paragraph (b) of AD 2002-20-07 R1. 
However, we inadvertently omitted it from Table 1 in paragraph (b) of 
the NPRM. Doing the action required by paragraph (f) or (h) of this AD 
ends the requirements of AD 97-14-04 and the other ADs identified in 
Table 1 of this AD. We have revised Table 1 accordingly.

Request To Revise the Applicability

    Southwest Airlines requests that the applicability of the NPRM be 
revised to affect Model 737-600, -700, -700C, -800 and -900 series 
airplanes (i.e., 737 next generation airplanes), line numbers 1 through 
1947 only (no change requested for affected Model 737-100 through -500 
series airplanes). Southwest Airlines states that the effectivity of 
Boeing Alert Service Bulletin 737-27A1279, dated June 20, 2006; and 
Boeing Alert Service Bulletin 737-27A1280, dated May 25, 2006; indicate 
that 737 next generation airplanes with line numbers 1948 or higher 
have an enhanced rudder control system with the improved rods already 
installed. Southwest Airlines also states that it is a hardship to 
require AD reporting on airplanes that have been modified in 
production.
    We do not agree with Southwest Airlines to exclude airplanes on 
which an enhanced rudder control system with new input control rods has 
been installed in production from the applicability of this AD. 
Paragraph (j) of this AD states, ``As of the effective date of this AD, 
no person may install an input control rod, P/N 251A3495-1, on any 
airplane.'' All Model 737 airplanes, including those in production now 
and in the future, are subject to this requirement. Therefore, we have 
determined that the applicability of the AD is correct as proposed.

Request To Exclude Certain Airplanes From Paragraph (g) of the NPRM

    Southwest Airlines requests that paragraph (g) be revised to 
exclude airplanes for which maintenance records can conclusively show 
that the suspect rods have not been installed. Southwest Airlines 
states that some airplanes have had control rods replaced or modified 
with the latest kits.
    We partially agree. We agree with Southwest Airlines that no 
further work is required by paragraph (g) for airplanes on which the 
input control rods have been replaced in accordance with paragraph 
(g)(4) of this AD. We also find that no further work is required by 
paragraph (h) for airplanes on which the input control rods have been 
installed in accordance with paragraph (h) of this AD. We have 
determined that those actions adequately address the identified unsafe 
condition of this AD related to the input

[[Page 4628]]

control rods. However, we do not agree to revise this AD. Operators are 
given credit for work previously done by the means of the phrase in the 
``Compliance'' section of the AD that states, ``* * * unless the 
actions have already been done.'' Therefore, in the case of this AD, if 
the actions required by paragraph (g)(4) or (h) of this AD (i.e., 
replacement of input control rods or installation of a new rudder 
control system) have been done in accordance with the service 
information identified in Table 4 or 5 of this AD, respectively, before 
the effective date of this AD, this AD does not require those actions 
to be repeated.

Request To Delete Reference to Certain Group Configurations

    AirTran Airways supports the proposed actions described in the 
NPRM, but points out a discrepancy between the NPRM and a referenced 
service bulletin. AirTran Airways notes that paragraph (g)(1)(iii) of 
the NPRM is applicable to airplanes identified as Group 1, 
Configuration 1, and Group 2, Configurations 1 and 2, in Boeing Alert 
Service Bulletin 737-27A1280, dated May 25, 2006. AirTran Airways 
states that the service bulletin does not contain any configurations 
for Group 2.
    From this comment, we infer that AirTran Airways is requesting that 
we delete the reference to Configurations 1 and 2 for Group 2 specified 
in paragraphs (g)(1)(iv), (g)(2)(i), and (g)(2)(ii) of this AD 
(paragraph (g)(1)(iii) in the NPRM). We agree and have revised this AD 
accordingly.

Request To Delete Concurrent Requirements

    Southwest Airlines states that it is impossible to install the 
enhanced rudder system without doing the concurrent requirements in 
paragraph (i) of the NPRM. Southwest Airlines notes that each of the 
service bulletins identified in Table 5 of the NPRM, except ``[Boeing] 
[S]ervice [B]ulletin 737-55-1042,'' is listed in the initial release of 
the primary service bulletins identified in Table 4 of the NPRM. 
Southwest Airlines believes it is impossible to trim the spar as 
illustrated in the primary service bulletins unless the trim was 
previously accomplished per ``[Boeing] [S]ervice [B]ulletin 737-55-
1042.'' Southwest Airlines also believes that the NPRM validates this 
by not requiring rework other than for the discrepant control rods.
    From this comment, we infer that Southwest Airlines is requesting 
that the concurrent requirements specified in paragraph (i) of the NPRM 
be deleted. Since Boeing Service Bulletin 737-55-1042 describes 
procedures unrelated to the subject of this AD, we also infer that 
Southwest Airlines meant to refer to Boeing Service Bulletin 737-55-
1052, Revision 1, dated August 5, 2004 (referred to in paragraph 
(i)(2)(iv) of this AD as a concurrent requirement). We do not agree 
with Southwest Airlines to delete the concurrent requirements of this 
AD. Our current policy specifies that service information must be 
``published'' (i.e., incorporation by reference (IBR)) if the AD 
mandates a method of compliance that is contained only in the 
referenced service information. As in the case of this AD, the 
concurrent requirement actions specified in Table 6 of the AD are 
contained only in the service information identified in that table, not 
in the primary service information identified in Table 5 of this AD. 
Therefore, we have made no change to this AD in this regard.

FAA's Determination and Requirements of This AD

    The unsafe condition described previously is likely to exist or 
develop on other airplanes of the same type design. For this reason, we 
are issuing this AD to supersede AD 2002-20-07 R1. This AD supersedes 
AD 2002-20-07 R1 and retains the requirements of the existing AD. This 
AD also requires accomplishing the actions specified in the applicable 
service information identified previously, except as discussed under 
``Differences Between the AD and Certain Service Information.'' For 
certain airplanes, this AD also requires suspending a certain Master 
Minimum Equipment List item, until all improperly heat-treated input 
control rods are replaced.

Differences Between the AD and Certain Service Information

    For certain Model 737-600, -700, -700C, -800, and -900 series 
airplanes on which the suspect input control rod of the standby rudder 
PCU was installed during production, the compliance times for the 
following actions required by this AD are different (i.e., shorter 
intervals) than those specified in Boeing Alert Service Bulletin 737-
27A1279, dated June 20, 2006; and Boeing Alert Service Bulletin 737-
27A1280, dated May 25, 2006:
     For the operational tests of the standby hydraulic 
actuation system: This AD specifies an initial compliance time of 
within 110 flight hours or 7 days after the effective date of this AD, 
whichever occurs later, and repetitive intervals of 110 flight hours or 
7 days, whichever occurs later, whereas Boeing Alert Service Bulletin 
737-27A1280 specifies an initial compliance time of within 60 days and 
repetitive intervals of 500 flight hours.
     For the replacement of the input control rod of the 
standby rudder PCU: This AD specifies a compliance time of within 90 
days after the effective date of this AD whereas Boeing Alert Service 
Bulletin 737-27A1279 specifies a compliance time of 24 months.
    As discussed previously in the ``Discussion'' section of this AD, 
the proposed compliance times for these actions may not detect and 
correct failure of the input control rod of the standby rudder PCU in a 
timely manner. While we do not yet have data on the growth rate of 
these cracks, we believe the revised compliance times described 
previously are adequate to ensure safety without imposing undue burdens 
on air commerce. In developing appropriate compliance times for these 
actions in this AD, we considered the safety implications, parts 
availability, and normal maintenance schedules for the timely 
accomplishment of the operational tests and replacements. In 
consideration of these items, as well as the reported failures of the 
input control rods in service, we have determined that the compliance 
times in this AD will ensure an acceptable level of safety and allow 
the actions to be done during scheduled maintenance intervals for most 
affected operators.

Changes to NPRM

    As a result of the differences between the AD and certain service 
information described previously, we have revised the applicable 
compliance times in this AD and changed certain paragraph identifiers 
and tables and added others.
    In certain places in the NPRM, we referred to the incorrect year of 
the issuance date of Boeing Alert Service Bulletin 737-27A1280. The 
correct issuance date is May 25, 2006, not May 25, 2005. We have 
corrected this error in this AD.

FAA's Determination of the Effective Date

    Regarding the reduced compliance times described previously, an 
unsafe condition exists that requires the immediate adoption of this 
AD; therefore, providing notice and opportunity for public comment 
before the AD is issued is impracticable, and good cause exists to make 
this AD effective in less than 30 days.

Comments Invited

    Regarding the reduced compliance times described previously, this 
AD is a final rule that involves requirements that affect flight safety 
and was not

[[Page 4629]]

preceded by notice and an opportunity for public comment; however, we 
invite you to submit any relevant written data, views, or arguments 
regarding this AD. Send your comments to an address listed in the 
ADDRESSES section. Include ``Docket No. FAA-2006-26323; Directorate 
Identifier 2006-NM-150-AD'' at the beginning of your comments. We 
specifically invite comments on the overall regulatory, economic, 
environmental, and energy aspects of the AD that might suggest a need 
to modify it.
    We will post all comments we receive, without change, to http://lldms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this AD. Using the search function of that Web 
site, 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 may review the DOT's complete Privacy Act Statement in the Federal 
Register published on April 11, 2000 (65 FR 19477-78), or you may visit 
http://dms.dot.gov.

Examining the Docket

    You may 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 Docket Management System 
receives them.

Authority for This Rulemaking

    Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
subtitle VII, part A, subpart III, section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation is within 
the scope of that authority because it addresses an unsafe condition 
that is likely to exist or develop on products identified in this 
rulemaking action.

Regulatory Findings

    We have determined that this AD will not have federalism 
implications under Executive Order 13132. This AD 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.
    For the reasons discussed above, I certify that the 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 AD and placed it in the AD docket. 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, Incorporation by 
reference, Safety.

Adoption of the Amendment

0
Accordingly, under the authority delegated to me by the Administrator, 
the FAA amends part 39 of the Federal Aviation Regulations (14 CFR part 
39) as follows:

PART 39--AIRWORTHINESS DIRECTIVES

0
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]

0
2. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
removing amendment 39-12940 (67 FR 67518, November 6, 2002) and adding 
the following new airworthiness directive (AD):

2007-03-07 Boeing: Amendment 39-14918. Docket No. FAA-2006-26323; 
Directorate Identifier 2006-NM-150-AD.

Effective Date

    (a) This AD becomes effective February 16, 2007.

Affected ADs

    (b) This AD affects the ADs specified in paragraphs (b)(1), 
(b)(2), and (b)(3) of this AD.
    (1) This AD supersedes AD 2002-20-07 R1.
    (2) For airplanes on which the actions required by paragraph (f) 
of this AD have been done before the effective date of this AD: 
Doing the actions in paragraph (f) of this AD ends the requirements 
of the ADs listed in Table 1 of this AD.
    (3) For airplanes on which the actions required by paragraph (f) 
of this AD have not been done before the effective date of this AD: 
Doing the actions in paragraph (h) of this AD ends the requirements 
of the ADs listed in Table 1 of this AD.

                           Table 1.--Other ADs
------------------------------------------------------------------------
                          AD--                              Amendment--
------------------------------------------------------------------------
97-09-15 R1.............................................        39-10912
97-14-04................................................        39-10061
99-11-05................................................        39-11175
2000-22-02 R1...........................................        39-11948
------------------------------------------------------------------------

Applicability

    (c) This AD applies to all Boeing Model 737-100, -200, -200C, -
300, -400, -500, -600, -700, -700C, -800 and -900 series airplanes, 
certificated in any category.

Unsafe Condition

    (d) This AD results from a report of a fractured rod end of an 
input control rod of the main rudder power control unit (PCU) and a 
subsequent report of a fractured rod end of the input control rod of 
the standby rudder PCU. We are issuing this AD to prevent failure of 
one of the two input control rods of the main rudder PCU, which, 
under certain conditions, could result in reduced controllability of 
the airplane; and to prevent failure of any combination of two input 
control rods of the main rudder PCU and/or standby rudder PCU, which 
could cause an uncommanded rudder hardover event and result in loss 
of control 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.

Requirements of AD 2002-20-07 R1

Installation

    (f) Except as provided by paragraphs (h) and (i) of this AD: 
Within 6 years after November 12, 2002 (the effective date of AD 
2002-20-07), do the actions required by paragraphs (f)(1) and (f)(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 input 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 PCU; and an input to the standby PCU 
that also will include an override mechanism.

[[Page 4630]]

    (2) Make applicable changes to the adjacent systems to 
accommodate the new rudder control system.

New Requirements of This AD

For Certain Airplanes: Tests, Suspension of Certain Master Minimum 
Equipment List Item, Replacements, Inspection, and Corrective Actions

    (g) For airplanes on which the actions required by paragraph (f) 
of this AD have been done before the effective date of this AD: Do 
the actions in paragraphs (g)(1) through (g)(4) of this AD, as 
applicable.
    (1) At the applicable times listed in paragraph 1.E., 
``Compliance,'' of the applicable service bulletin specified in 
Table 2 of this AD; except, where the service bulletin specifies a 
compliance time from the date on the service bulletin, this AD 
requires compliance within the specified compliance time after the 
effective date of this AD: Do the tests specified in Table 2 of this 
AD, until all applicable actions required by paragraph (g)(4) of 
this AD have been done in accordance with the applicable service 
bulletin specified in Table 4 of this AD. Do all applicable 
corrective actions specified in Table 2 of this AD before further 
flight.

            Table 2.--Repetitive Tests for Certain Airplanes
------------------------------------------------------------------------
                                                     In accordance with
         For model--                  Do--           the accomplishment
                                                      instructions of--
------------------------------------------------------------------------
(i) 737-100, -200, and -200C  The ``Rudder Main     Boeing Alert Service
 series airplanes identified   Power Control Unit    Bulletin 737-
 as Group 1, Configuration     Force Fight Test,''   27A1281, dated June
 1, in the service bulletin.   the ``Standby         14, 2006.
                               Rudder Actuator
                               Shutoff Valve
                               Test,'' and any
                               applicable
                               corrective action.
(ii) 737-300, -400, and -500  The ``Rudder Main     Boeing Alert Service
 series airplanes identified   Power Control Unit    Bulletin 737-
 as Group 2, Configuration     Force Fight Test,''   27A1281, dated June
 1, in the service bulletin.   the ``Standby         14, 2006.
                               Rudder Actuator
                               Shutoff Valve
                               Test,'' and any
                               applicable
                               corrective action.
(iii) 737-600, -700, -700C, - The ``Rudder Main     Boeing Alert Service
 800, and -900 series          Power Control Unit    Bulletin 737-
 airplanes identified as       Force Fight Monitor   27A1280, dated May
 Group 1, Configuration 1,     Test,'' the           25, 2006.
 in the service bulletin.      ``Operational Test
                               of the Standby
                               Hydraulic Actuation
                               System,'' and any
                               applicable
                               corrective action.
(iv) 737-600, -700, -700C, -  The ``Rudder Main     Boeing Alert Service
 800, and -900 series          Power Control Unit    Bulletin 737-
 airplanes identified as       Force Fight Monitor   27A1280, dated May
 Group 2 in the service        Test,'' and any       25, 2006.
 bulletin.                     applicable
                               corrective action.
------------------------------------------------------------------------

    (2) At the applicable times listed in Table 3 of this AD, do the 
``Operational Test of the Standby Hydraulic Actuation System,'' and 
any applicable corrective action, until all applicable actions 
required by paragraph (g)(4) of this AD have been done in accordance 
with the applicable service bulletin specified in Table 4 of this 
AD. The actions must be done in accordance with the Accomplishment 
Instructions of Boeing Alert Service Bulletin 737-27A1280, dated May 
25, 2006. Do all applicable corrective actions before further 
flight.

                          Table 3.--Repetitive Operational Tests for Certain Airplanes
----------------------------------------------------------------------------------------------------------------
                                                                  Do the ``Operational
                                          On which the input      Test of the Standby     And repeat the test at
             For model--                  control rod of the      Hydraulic Actuation        intervals not to
                                         standby rudder PCU--          System''--                exceed--
----------------------------------------------------------------------------------------------------------------
(i) 737-600, -700, -700C, -800, and -  Has not been replaced    Within 110 flight hours  110 flight hours or 7
 900 series airplanes identified as     as required by           or 7 days after the      days, whichever occurs
 Group 2 in the service bulletin.       paragraph (g)(4)(v) of   effective date of this   later.
                                        this AD.                 AD, whichever occurs
                                                                 later.
(ii) 737-600, -700, -700C, -800, and - Has been replaced as     Within 60 days after     500 flight hours.
 900 series airplanes identified as     required by paragraph    the effective date of
 Group 2 in the service bulletin.       (g)(4)(v) of this AD.    this AD.
----------------------------------------------------------------------------------------------------------------

    (3) As of the effective date of this AD, do not use the Master 
Minimum Equipment List Item 27-21, ``STBY RUD ON light,'' until all 
applicable actions required by paragraph (g)(4) of this AD are done.
    (4) At the applicable time specified in Table 4 of this AD, do 
the replacement(s) and inspection, as applicable, specified in that 
table. Do all applicable corrective actions specified in Table 4 of 
this AD before further flight. Doing all applicable actions ends the 
requirements of paragraphs (g)(1) through (g)(3) of this AD.

          Table 4.--Replacement of Input Control Rods, Inspection, and Corrective Action, as Applicable
----------------------------------------------------------------------------------------------------------------
                                                                                                And do the
                                           Do the following                                 replacement(s) and
             For model--                     action(s)--          In accordance with--        inspection, as
                                                                                               applicable--
----------------------------------------------------------------------------------------------------------------
(i) 737-100, -200, and -200C series    Replace both input       Part 2 of the            Within 24 months after
 airplanes identified as Groups 1       control rods of the      Accomplishment           the effective date of
 through 9, Configuration 3, in the     main rudder PCU with     Instructions of Boeing   this AD.
 service bulletin.                      new input control rods.  Service Bulletin 737-
                                                                 27-1252, Revision 3,
                                                                 dated May 12, 2006.

[[Page 4631]]

 
(ii) 737-300, -400, and -500 series    Replace both input       Part 2 of the            Within 24 months after
 airplanes identified as Groups 1       control rods of the      Accomplishment           the effective date of
 through 19, Configuration 3, in the    main rudder PCU with     Instructions of Boeing   this AD.
 service bulletin.                      new input control rods.  Service Bulletin 737-
                                                                 27-1255, Revision 3,
                                                                 dated May 10, 2006.
(iii) 737-600, -700, -700C, -800, and  Replace both input       Part 2 of the            Within 24 months after
 -900 series airplanes identified as    control rods of the      Accomplishment           the effective date of
 Groups 1 through 20, Configuration     main rudder PCU with     Instructions of Boeing   this AD.
 3, in the service bulletin.            new input control        Service Bulletin 737-
                                        rods, inspect the        27-1253, Revision 3,
                                        input control rod of     dated May 12, 2006.
                                        the standby rudder PCU
                                        to determine if part
                                        number (P/N) 251A3495-
                                        1 is installed, and do
                                        any corrective action.
(iv) 737-600, -700, -700C, -800, and - Replace both input       The Accomplishment       Within 24 months after
 900 series airplanes identified as     control rods of the      Instructions of Boeing   the effective date of
 Group 1 in the service bulletin.       main rudder PCU with     Alert Service Bulletin   this AD.
                                        new input control rods.  737-27A1279, dated
                                                                 June 20, 2006.
(v) 737-600, -700, -700C, -800, and -  Replace the input        The Accomplishment       Within 90 days after
 900 series airplanes identified as     control rod of the       Instructions of Boeing   the effective date of
 Group 1 in the service bulletin.       standby rudder PCU       Alert Service Bulletin   this AD.
                                        with a new input         737-27A1279, dated
                                        control rod.             June 20, 2006.
----------------------------------------------------------------------------------------------------------------

For Certain Other Airplanes: Install New Rudder Control System Per 
Service Information

    (h) For airplanes on which the actions required by paragraph (f) 
of this AD have not been done before the effective date of this AD: 
As of the effective date of this AD, use the applicable service 
bulletin specified in Table 5 of this AD to do the actions required 
by paragraph (f) of this AD at the time specified in that paragraph.

   Table 5.--Service Bulletins for Installation of New Rudder Control
                                 System
------------------------------------------------------------------------
                                                       Do the actions
                                                         required by
         For model--             Identified as--      paragraph (f) of
                                                         this AD in
                                                      accordance with--
------------------------------------------------------------------------
(1) 737-100, -200, and -200C  Groups 1 through 9,   Part 1 of the
 series airplanes.             Configurations 1      Accomplishment
                               and 2, in the         Instructions of
                               service bulletin.     Boeing Service
                                                     Bulletin 737-27-
                                                     1252, Revision 3,
                                                     dated May 12, 2006.
(2) 737-300, -400, and -500   Groups 1 through 19,  Part 1 of the
 series airplanes.             Configurations 1      Accomplishment
                               and 2, in the         Instructions of
                               service bulletin.     Boeing Service
                                                     Bulletin 737-27-
                                                     1255, Revision 3,
                                                     dated May 10, 2006.
(3) 737-600, -700, -700C, -   Groups 1 through 20,  Part 1 of the
 800, and -900 series          Configurations 1      Accomplishment
 airplanes.                    and 2, in the         Instructions of
                               service bulletin.     Boeing Service
                                                     Bulletin 737-27-
                                                     1253, Revision 3,
                                                     dated May 12, 2006.
------------------------------------------------------------------------

    (i) Before or concurrently with the requirements of paragraph 
(h) of this AD, do the actions specified in Table 6 of this AD.

                Table 6.--Before/Concurrent Requirements
------------------------------------------------------------------------
                                                     In accordance with
 Before or concurrently with   Do these actions--    the accomplishment
 the actions specified in--                           instructions of--
------------------------------------------------------------------------
(1) Paragraph (h)(1) of this  (i) Remove the        Boeing Service
 AD.                           rudder position       Bulletin 737-22-
                               sensor of the         1042, Revision 1,
                               automatic flight      dated April 5,
                               control system.       1985.
                              (ii) Replace the      Boeing 737 Service
                               rudder feel and       Bulletin 27-1026,
                               centering assembly    dated January 15,
                               with a new all-       1971.
                               mechanical unit.
                              (iii) Install the     Boeing Service
                               rudder pressure       Bulletin 737-
                               reducer and yaw       27A1206, Revision
                               damper coupler.       3, dated December
                                                     14, 2000.
                              (iv) Install          Boeing Service
                               provisional wires     Bulletin 737-27-
                               for rudder system     1246, Revision 1,
                               enhancement.          including Appendix
                                                     A, dated February
                                                     21, 2002.
                              (v) Replace the P5-3  Boeing Service
                               panel with a new      Bulletin 737-27-
                               panel.                1263, Revision 1,
                                                     dated September 25,
                                                     2003.
                              (vi) Replace the      Smiths Aerospace
                               input lever for the   Actuation Systems
                               auxiliary rudder      Service Bulletin
                               power control         1150-27-05A, dated
                               package with a new    August 28, 2003.
                               input lever.

[[Page 4632]]

 
(2) Paragraph (h)(2) of this  (i) Install           Boeing Service
 AD.                           provisional wires     Bulletin 737-27-
                               for rudder system     1246, Revision 1,
                               enhancement.          including Appendix
                                                     A, dated February
                                                     21, 2002.
                              (ii) Replace the P5-  Boeing Service
                               3 panel with a new    Bulletin 737-27-
                               panel.                1264, Revision 1,
                                                     dated April 3,
                                                     2003.
                              (iii) Install a new   Boeing Service
                               yaw damper coupler.   Bulletin 737-
                                                     27A1206, Revision
                                                     3, dated December
                                                     14, 2000.
                              (iv) Inspect the      Boeing Service
                               trailing edge beam    Bulletin 737-55-
                               on the vertical fin   1052, Revision 1,
                               and rework if         dated August 5,
                               necessary.            2004.
                              (v) Replace the       Smiths Aerospace
                               input lever for the   Actuation Systems
                               auxiliary rudder      Service Bulletin
                               power control         1150-27-05A, dated
                               package with a new    August 28, 2003.
                               input lever.
(3) Paragraph (h)(3) of this  (i) Install           Boeing Service
 AD.                           provisional wires     Bulletin 737-27-
                               for rudder system     1247, Revision 1,
                               enhancement.          dated July 25,
                                                     2002.
                              (ii) Replace the P5-  Boeing Service
                               3 panel with a new    Bulletin 737-27-
                               panel.                1262, dated
                                                     December 19, 2002.
                              (iii) Relocate the    Boeing Alert Service
                               wire bundle routing   Bulletin 737-
                               in the vertical       27A1239, dated
                               stabilizer.           January 11, 2001.
------------------------------------------------------------------------

Parts Installation

    (j) As of the effective date of this AD, no person may install 
an input control rod, P/N 251A3495-1, on any airplane.

Alternative Methods of Compliance (AMOCs)

    (k)(1) The Manager, Seattle ACO, FAA, has the authority to 
approve AMOCs for this AD, if requested in accordance with the 
procedures found in 14 CFR 39.19.
    (2) Before using any AMOC approved in accordance with Sec.  
39.19 on any airplane to which the AMOC applies, notify the 
appropriate principal inspector in the FAA Flight Standards 
Certificate Holding District Office.
    (3) Except as provided by paragraph (j) of this AD: AMOCs 
approved previously in accordance with AD 2002-20-07 R1 are approved 
as AMOCs for the corresponding provisions of paragraphs (f) and (h) 
of this AD.

Material Incorporated by Reference

    (l) You must use the applicable service bulletin specified in 
Table 7 of this AD to perform the actions that are required by this 
AD, unless the AD specifies otherwise. Boeing Service Bulletin 737-
22-1042, Revision 1, dated April 5, 1985, contains the following 
effective pages:

------------------------------------------------------------------------
                                  Revision level
           Page Nos.              shown on page      Date shown on page
------------------------------------------------------------------------
1-7, 9........................  1................  April 5, 1985.
8.............................  Original.........  July 1, 1983.
------------------------------------------------------------------------

The Director of the Federal Register approved the incorporation by 
reference of these documents in accordance with 5 U.S.C. 552(a) and 
1 CFR part 51. Contact Boeing Commercial Airplanes, P.O. Box 3707, 
Seattle, Washington 98124-2207, for a copy of this service 
information. You may review copies at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue, SW., Renton, Washington; or at the 
National Archives and Records Administration (NARA). For information 
on the availability of this material at NARA, call 202-741-6030, or 
go to: http://www.archives.gov/federal-register/cfr/ibr-locations.html.

                                  Table 7.--Material Incorporated by Reference
----------------------------------------------------------------------------------------------------------------
         Boeing Service Bulletin                   Revision level                          Date
----------------------------------------------------------------------------------------------------------------
Boeing Alert Service Bulletin 737-27A1239  Original.....................  January 11, 2001.
 Boeing Alert Service Bulletin 737-        Original.....................  June 20, 2006.
 27A1279.
 Boeing Alert Service Bulletin 737-        Original.....................  May 25, 2006.
 27A1280.
 Boeing Alert Service Bulletin 737-        Original.....................  June 14, 2006.
 27A1281.
 Boeing Alert Service Bulletin 737-22-     1............................  April 5, 1985.
 1042.
 Boeing Alert Service Bulletin 737-        3............................  December 14, 2000.
 27A1206.
 Boeing Alert Service Bulletin 737-27-     1............................  February 21, 2002.
 1246, including Appendix A.
 Boeing Alert Service Bulletin 737-27-     1............................  July 25, 2002.
 1247.
 Boeing Alert Service Bulletin 737-27-     3............................  May 12, 2006.
 1252.
 Boeing Alert Service Bulletin 737-27-     3............................  May 12, 2006.
 1253.
 Boeing Alert Service Bulletin 737-27-     3............................  May 10, 2006.
 1255.
 Boeing Alert Service Bulletin 737-27-     Original.....................  December 19, 2002.
 1262.
 Boeing Alert Service Bulletin 737-27-     1............................  September 25, 2003.
 1263.
 Boeing Alert Service Bulletin 737-27-     1............................  April 3, 2003.
 1264.
 Boeing Alert Service Bulletin 737-55-     1............................  August 5, 2004.
 1052.
 Boeing 737 Alert Service Bulletin 27-     Original.....................  January 15, 1971.
 1026.
Smiths Aerospace Actuation Systems         Original.....................  August 28, 2003.
 Service Bulletin 1150-27-05A.
----------------------------------------------------------------------------------------------------------------



[[Page 4633]]

    Issued in Renton, Washington, on January 25, 2007.
Ali Bahrami,
Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E7-1496 Filed 1-31-07; 8:45 am]
BILLING CODE 4910-13-P