[Federal Register Volume 64, Number 139 (Wednesday, July 21, 1999)]
[Rules and Regulations]
[Pages 39003-39005]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-18198]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-247-AD; Amendment 39-11227; AD 99-15-08]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747-200 and -300 Series
Airplanes Equipped With General Electric CF6-80C2 Series Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment supersedes an existing airworthiness directive
(AD), applicable to certain Boeing Model 747-200 and -300 series
airplanes, that currently requires various inspections and functional
tests to detect discrepancies of the thrust reverser control and
indication system, and correction of any discrepancy found. This
amendment reduces the repetitive interval for one certain functional
test. This amendment is prompted by reports indicating that several
center drive units (CDU) were returned to the manufacturer of the CDU's
because of low holding torque of the CDU cone brake. The actions
specified by this AD are intended to ensure the integrity of the fail
safe features of the thrust reverser system by preventing possible
failure modes in the thrust reverser control system that can result in
inadvertent deployment of a thrust reverser during flight.
DATES: Effective August 25, 1999.
The incorporation by reference of Boeing Service Bulletin 747-
78A2166, Revision 1, dated October 9, 1997, as listed in the
regulations, is approved by the Director of the Federal Register as of
August 25, 1999.
The incorporation by reference of Boeing Alert Service Bulletin
747-78A2130, dated May 26, 1994, was approved previously by the
Director of the Federal Register as of April 13, 1995 (60 FR 13623,
March 14, 1995).
ADDRESSES: The service information referenced in this AD may be
obtained from Boeing Commercial Airplane Group, P.O. Box 3707, Seattle,
Washington 98124-2207. This information may be examined at the Federal
Aviation Administration (FAA), Transport Airplane Directorate, Rules
Docket, 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: Holly Thorson, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (425) 227-1357; fax (425) 227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) by superseding AD 95-06-01,
amendment 39-9171 (60 FR 13623, March 14, 1995), which is applicable to
certain Boeing Model 747-200 and -300 series airplanes, was published
in the Federal Register on January 21, 1999 (64 FR 3226). The action
proposed to continue to require various inspections and functional
tests to detect discrepancies of the thrust reverser control and
indication system, and correction of any discrepancy found. The action
also proposed to reduce the repetitive interval for one certain
functional test.
Comments
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the single comment received.
The commenter supports the proposed rule.
Explanation of Change to the Final Rule
In the notice of proposed rulemaking (NPRM), the FAA proposed to
require repetitive functional tests of the CDU cone brake on Model 747-
200 and -300 series airplanes, at intervals not to exceed 650 hours
time-in-service, regardless of whether the airplane is equipped with
thrust reversers modified in accordance with Boeing Service Bulletin
747-78-2144. Since the issuance of the NPRM, the FAA has determined
that a repetitive interval of 1,000 hours time-in-service would
adequately ensure safety on airplanes equipped with thrust reversers
modified in accordance with Boeing Service Bulletin 747-78-2144,
Revision 1, dated April 11, 1996. This decision is based on the FAA's
determination that frequent maintenance on such systems as the thrust
reverser system could increase the risk of maintenance errors. Also,
Boeing Service Bulletin 747-78-
[[Page 39004]]
2144, Revision 1, recommends functional tests at intervals not to
exceed 1,000 hours time-in-service for thrust reversers that have been
modified to incorporate a third locking device in accordance with that
service bulletin. Performing the functional test of the cone brake at
the same interval as the functional test of the third locking device
would allow both thrust reverser tests to be scheduled and performed at
the same time. Therefore, paragraph (d) of this final rule has been
revised accordingly, and new paragraphs (d)(1) and (d)(2) have been
added to this final rule.
Conclusion
After careful review of the available data, including the comment
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule with the changes described
previously. The FAA has determined that these changes will neither
increase the economic burden on any operator nor increase the scope of
the AD.
Interim Action
This is considered to be interim action. The manufacturer has
advised that it currently is developing a modification that will
positively address the unsafe condition addressed by this AD. Once this
modification is developed, approved, and available, the FAA may
consider additional rulemaking.
Cost Impact
There are approximately 9 airplanes of the affected design in the
worldwide fleet. The FAA estimates that 2 airplanes of U.S. registry
will be affected by this AD.
The actions required by this AD will not add any additional
economic burden on affected operators, other than the costs that are
associated with repeating the functional test of the cone brake at
reduced intervals (at intervals not to exceed 650 hours time-in-service
rather than at intervals not to exceed 1,000 hours time-in-service).
The current costs associated with AD 95-06-01 are reiterated in their
entirety (as follows) for the convenience of affected operators.
The actions that are currently required by AD 95-06-01, and
retained in this AD, take approximately 33 work hours per airplane to
accomplish, at an average labor rate of $60 per work hour. Based on
these figures, the cost impact of the currently required actions on
U.S. operators is estimated to be $3,960, or $1,980 per airplane, per
inspection/test cycle.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the requirements of this AD
action, and that no operator would accomplish those actions in the
future if this AD were not adopted.
Regulatory Impact
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.
For the reasons discussed above, I certify that this action (1) is
not a ``significant regulatory action'' under Executive Order 12866;
(2) is not a ``significant rule'' under 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. A final evaluation has been prepared for this action
and it is contained in the Rules Docket. A copy of it 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. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by removing amendment 39-9171 (60 FR
13623, March 14, 1995), and by adding a new airworthiness directive
(AD), amendment 39-11227, to read as follows:
99-15-08 Boeing: Amendment 39-11227. Docket 98-NM-247-AD.
Supersedes AD 95-06-01, Amendment 39-9171.
Applicability: Model 747-200 and -300 series airplanes equipped
with General Electric Model CF6-80C2 series engines with Power
Management Control engine controls, 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 (f) 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 ensure the integrity of the fail safe features of the thrust
reverser system by preventing possible failure modes in the thrust
reverser control system that can result in inadvertent deployment of
a thrust reverser during flight, accomplish the following:
Restatement of Requirements of AD 95-06-01
(a) Within 90 days after April 13, 1995 (the effective date of
AD 95-06-01, amendment 39-9171), perform tests of the position
switch module and the cone brake of the center drive unit (CDU) on
each thrust reverser, and perform an inspection to detect damage to
the bullnose seal on the translating sleeve on each thrust reverser,
in accordance with paragraphs III.A. through III.C. of the
Accomplishment Instructions of Boeing Alert Service Bulletin 747-
78A2130, dated May 26, 1994. Repeat the tests and inspection
thereafter at intervals not to exceed 1,000 hours time-in-service
until the functional test required by paragraph (d) of this AD is
accomplished.
(b) Within 9 months after April 13, 1995, perform inspections
and functional tests of the thrust reverser control and indication
system in accordance with paragraphs III.D. through III.F., III.H.,
and III.I. of the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-78A2130, dated May 26, 1994. Repeat these
inspections and functional tests thereafter at intervals not to
exceed 18 months.
(c) If any of the inspections and/or functional tests required
by paragraphs (a) and (b) of this AD cannot be successfully
performed, or if any discrepancy is found during those inspections
and/or functional tests, accomplish either paragraph (c)(1) or
(c)(2) of this AD.
(1) Prior to further flight, correct the discrepancy found, in
accordance with Boeing Alert Service Bulletin 747-78A2130, dated May
26, 1994. Or
[[Page 39005]]
(2) The airplane may be operated in accordance with the
provisions and limitations specified in an operator's FAA-approved
Minimum Equipment List (MEL), provided that no more than one thrust
reverser on the airplane is inoperative.
New Requirements of This AD
(d) Within 1,000 hours time-in-service after the most recent
test of the CDU cone brake performed in accordance with paragraph
(a) of this AD, or within 650 hours time-in-service after the
effective date of this AD, whichever occurs first: Perform a
functional test to detect discrepancies of the CDU cone brake on
each thrust reverser, in accordance with Boeing Service Bulletin
747-78A2166, Revision 1, dated October 9, 1997, or paragraph III.B.
of the Accomplishment Instructions of Boeing Alert Service Bulletin
747-78A2130, dated May 26, 1994. Repeat the functional test
thereafter at the interval specified in paragraph (d)(1) or (d)(2)
of this AD, as applicable. Accomplishment of such functional test
constitutes terminating action for the repetitive test of the CDU
cone brake required by paragraph (a) of this AD.
(1) For airplanes equipped with thrust reversers NOT modified in
accordance with Boeing Service Bulletin 747-78-2144, Revision 1,
dated April 11, 1996: Repeat the functional test at intervals not to
exceed 650 hours time-in-service.
(2) For airplanes equipped with thrust reversers modified in
accordance with Boeing Service Bulletin 747-78-2144, Revision 1,
dated April 11, 1996: Repeat the functional test at intervals not to
exceed 1,000 hours time-in-service.
(e) If any functional test required by paragraph (d) of this AD
cannot be successfully performed, or if any discrepancy is found
during any functional test required by paragraph (d) of this AD,
accomplish either paragraph (e)(1) or (e)(2) of this AD.
(1) Prior to further flight, correct the discrepancy found, in
accordance with Boeing Service Bulletin 747-78A2166, Revision 1,
dated October 9, 1997, or paragraph III.B. of the Accomplishment
Instructions of Boeing Alert Service Bulletin 747-78A2130, dated May
26, 1994. Or
(2) The airplane may be operated in accordance with the
provisions and limitations specified in the operator's FAA-approved
MEL, provided that no more than one thrust reverser on the airplane
is inoperative.
Alternative Methods of Compliance
(f) 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, FAA, Transport Airplane Directorate. 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 Permits
(g) Special flight permits may be issued in accordance with
sections 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.
Incorporation by Reference
(h) Except as provided by paragraphs (c)(2) and (e)(2) of this
AD, the actions shall be done in accordance with Boeing Alert
Service Bulletin 747-78A2130, dated May 26, 1994, or Boeing Service
Bulletin 747-78A2166, Revision 1, dated October 9, 1997, as
applicable.
(1) The incorporation by reference of Boeing Service Bulletin
747-78A2166, Revision 1, dated October 9, 1997, is approved by the
Director of the Federal Register in accordance with 5 U.S.C. 552(a)
and 1 CFR part 51.
(2) The incorporation by reference of Boeing Alert Service
Bulletin 747-78A2130, dated May 26, 1994, was approved previously by
the Director of the Federal Register as of April 13, 1995 (60 FR
13623, March 14, 1995).
(3) 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.
(i) This amendment becomes effective on August 25, 1999.
Issued in Renton, Washington, on July 12, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-18198 Filed 7-20-99; 8:45 am]
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