[Federal Register Volume 60, Number 72 (Friday, April 14, 1995)]
[Rules and Regulations]
[Pages 18981-18983]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-8828]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 95-NM-37-AD; Amendment 39-9199; AD 95-06-53]
Airworthiness Directives; Boeing Model 737 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This document publishes in the Federal Register an amendment
adopting Airworthiness Directive (AD) T95-06-53 that was sent
previously to all known U.S. owners and operators of Boeing Model 737
series airplanes by individual telegrams. This AD requires
identification of the part and serial numbers of the main rudder power
control unit (PCU), and replacement of certain PCU's with serviceable
parts, if necessary. This amendment is prompted by reports indicating
that certain modified rudder PCU's malfunctioned and failed functional
retesting. The actions specified by this AD are intended to prevent the
rudder actuator piston and the rudder from operating with reduced force
capability or moving in a direction opposite the intended direction due
to malfunctioning of the rudder PCU; these conditions could result in
reduced controllability of the airplane.
DATES: Effective May 1, 1995, to all persons except those persons to
whom it was made immediately effective by telegraphic AD T95-06-53,
issued March 14, 1995, which contained the requirements of this
amendment.
The incorporation by reference of Boeing Service Bulletin 737-27-
1185, [[Page 18982]] dated April 15, 1993, as listed in the
regulations, was approved previously by the Director of the Federal
Register as of March 3, 1994 (59 FR 4570, February 1, 1994).
Comments for inclusion in the Rules Docket must be received on or
before June 13, 1995.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-37-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
The applicable service information 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; or at the
Office of the Federal Register, 800 North Capitol Street, NW., suite
700, Washington, DC.
FOR FURTHER INFORMATION CONTACT: Kenneth W. Frey, Aerospace Engineer,
Systems and Equipment Branch, ANM-130S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,
SW., Renton, Washington 98055-4056; telephone (206) 227-2673; fax (206)
227-1181.
SUPPLEMENTARY INFORMATION: On January 3, 1994, the FAA issued AD 94-01-
07, amendment 39-8789 (59 FR 4570, February 1, 1994), which is
applicable to certain Boeing Model 737 series airplanes. That AD
requires repetitive tests of existing main rudder power control units
(PCU's), and eventual replacement of the main rudder PCU with a
modified PCU. The modified PCU also was required to be functionally
tested following modification and prior to installation. Recently, the
FAA received two reports of in-service malfunctioning of certain rudder
PCU's that had been modified by Aero Controls, Inc. Subsequently, these
PCU's were removed from the airplanes and failed functional retesting.
In both of the reported cases, the secondary slide in the servo
valve of these PCU's went past the intended maximum travel position. An
examination of the PCU's tested revealed that the spring retainer
backed off from the spring guide. If the secondary slide goes past the
intended maximum travel position, the rudder actuator piston and the
rudder could operate with reduced force capability or move in a
direction opposite the intended direction. These conditions, if not
corrected, could result in reduced controllability of the airplane.
Results of a preliminary investigation indicate that Aero Controls,
Inc., may not have been using the proper tool to torque the spring
retaining nut. The FAA has identified 36 PCU's that may have been
modified and/or tested incorrectly by that repair station. This AD
affects only those PCU's modified and/or tested by Aero Controls, Inc.
The FAA is currently in the process of verifying that other repair
stations and operators have properly modified and tested PCU's.
The FAA has confirmed that the PCU installed on the USAir Model 737
series airplane that was involved in an accident near Pittsburgh in
September 1994 had not been modified. The PCU from that airplane has
been subjected to thorough functional testing, and no evidence of
failures or deficiencies has been found. The investigation of that
accident is continuing. No determination has been made that the PCU was
the cause of that accident. This AD is being issued to correct the
conditions described above and is not related to the results of the
Pittsburgh accident investigation.
Since the unsafe condition described is likely to exist or develop
on other airplanes of the same type design, the FAA issued Telegraphic
AD T95-06-53. The AD requires identification of the part number and
serial number of the main rudder PCU, and replacement of certain PCU's
with serviceable parts, if necessary.
As a result of recent communications with the Air Transport
Association (ATA) of America, the FAA has learned that, in general,
some operators may misunderstand the legal effect of AD's on airplanes
that are identified in the applicability provision of the AD, but that
have been altered or repaired in the area addressed by the AD. The FAA
points out that all airplanes identified in the applicability provision
of an AD are legally subject to the AD. If an airplane has been altered
or repaired in the affected area in such a way as to affect compliance
with the AD, the owner or operator is required to obtain FAA approval
for an alternative method of compliance with the AD, in accordance with
the paragraph of each AD that provides for such approvals. A note has
been included in this rule to clarify this long-standing requirement.
Since it was found that immediate corrective action was required,
notice and opportunity for prior public comment thereon were
impracticable and contrary to the public interest, and good cause
existed to make the AD effective immediately by individual telegrams
issued on March 14, 1995, to all known U.S. owners and operators of
Boeing Model 737 series airplanes. These conditions still exist, and
the AD is hereby published in the Federal Register as an amendment to
Sec. 39.13 of the Federal Aviation Regulations (14 CFR 39.13) to make
it effective to all persons.
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.
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 95-NM-37-AD.'' The postcard will be date stamped and
returned to the commenter.
The regulations adopted herein will not have substantial direct
effects 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, in
accordance with Executive Order 12612, it is determined that this final
rule does not have sufficient federalism implications to warrant the
preparation of a Federalism Assessment.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to [[Page 18983]] 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, Incorporation by
reference, 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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
95-06-53 Boeing: Amendment 39-9199. Docket 95-NM-37-AD.
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 requirements of
this AD is affected, the owner/operator must use the authority
provided in paragraph (d) to request approval from the FAA. This
approval may address either no action, if the current configuration
eliminates the unsafe condition; or different actions necessary to
address the unsafe condition described in this AD. Such a request
should include an assessment of the effect of the changed
configuration on the unsafe condition addressed by this AD. In no
case does the presence of any modification, alteration, or repair
remove any airplane from the applicability of this AD.
Compliance: Required as indicated, unless accomplished
previously.
To prevent the rudder actuator piston and the rudder from
operating with reduced force capability or moving in a direction
opposite the intended direction, and resultant reduced
controllability of the airplane, accomplish the following:
(a) Within 5 flights after the effective date of this AD,
identify the part number and serial number of the main rudder power
control unit (PCU).
(b) If the PCU is identified with a part number and serial
number specified in the list below, prior to further flight, remove
the PCU from the airplane, and replace it with a serviceable part.
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Part No. Serial No.(s)
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65C37052-3........ 17SS, 49, 90A, 101, 138, 149A, 191A, 308A, 374,
EGG0282.
65C37052-5........ 1211A.
65C37052-7........ 399A, 710A, 926A, 935A, 1175A, 1237A, 1493A, 1504A,
1546, 1561A, 67700.
65C37052-8........ 1090A, 1223, 1920, 2023A.
65C37052-9........ 0184, 247, 394A, 641A, 1739A, 1746A, 1796A, 1849A,
1997A, 2181A.
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(c) As of the effective date of this AD, no person shall install
on any airplane a rudder PCU having a part number and serial number
that is specified in the list contained in paragraph (b) of this AD
unless paragraphs (c)(1), (c)(2), (c)(3), and (c)(4) of this AD are
accomplished.
(1) Perform a functional test of the PCU in accordance with Part
II of the Accomplishment Instructions of Boeing Service Bulletin
737-27-1185, dated April 15, 1993. And
(2) Check the torque value on the spring retainer, Part Number
68021-5, to determine that it measures a minimum of 25 inch-pounds.
If the torque value is less than 25 inch-pounds, repair in
accordance with a method approved by the Manager, Seattle Aircraft
Certification Office (ACO), FAA, Transport Airplane Directorate. And
(3) Repeat the functional test required by paragraph (c)(1) of
this AD. The PCU must pass this functional test in order to be
returned to service. And
(4) The measurement required by paragraph (c)(2) of this AD must
be reported to the FAA, Transport Airplane Directorate, Seattle ACO,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; fax (206) 227-
1181. Information collection requirements contained in this
regulation have been approved by the Office of Management and Budget
(OMB) under the provisions of the Paperwork Reduction Act of 1980
(44 U.S.C. 3501 et seq.) and have been assigned OMB Control Number
2120-0056.
(d) An alternative method of compliance or adjustment of the
compliance time that provides an acceptable level of safety may be
used if approved by the Manager, Seattle ACO. Operators shall submit
their requests through an appropriate FAA Principal Maintenance
Inspector, who may add comments and then send it to the Manager,
Seattle ACO.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Seattle ACO.
(e) Special flight permits may be issued in accordance with
Secs. 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR
21.197 and 21.199) to operate the airplane to a location where the
requirements of this AD can be accomplished.
(f) The functional test shall be done in accordance with Boeing
Service Bulletin 737-27-1185, dated April 15, 1993. The
incorporation by reference of this document was approved previously
by the Director of the Federal Register in accordance with 5 U.S.C.
552(a) and 1 CFR part 51 as of March 3, 1994 (59 FR 4570, February
1, 1994). Copies may be obtained from Boeing Commercial Airplane
Group, P.O. Box 3707, Seattle, Washington 98124-2207. Copies may be
inspected at the FAA, Transport Airplane Directorate, 1601 Lind
Avenue, SW., Renton, Washington; or at the Office of the Federal
Register, 800 North Capitol Street, NW., suite 700, Washington, DC.
(g) This amendment becomes effective on May 1, 1995, to all
persons except those persons to whom it was made immediately
effective by telegraphic AD T95-06-53, issued on March 14, 1995,
which contained the requirements of this amendment.
Issued in Renton, Washington, on April 5, 1995.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-8828 Filed 4-13-95; 8:45 am]
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