[Federal Register Volume 60, Number 149 (Thursday, August 3, 1995)]
[Rules and Regulations]
[Pages 39631-39633]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-18435]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-06-AD; Amendment 39-9321; AD 95-16-02]
Airworthiness Directives; Boeing Model 747 SP, SR, -100, -200,
and -300 Series Airplanes Equipped with Pratt & Whitney Model JT9D
Series Engines (Excluding Model JT9D-70 Engines)
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 747 SP, SR, -100, -200, and -300
series airplanes, that requires repetitive operational tests of the
reversible gearbox pneumatic drive unit (PDU) or the reversing air
motor PDU to ensure that the unit can restrain the thrust reverser
sleeve, and correction of any discrepancy found. This amendment is
prompted by the results of an investigation, which revealed that, in
the event of thrust reverser deployment during high-speed climb or
during cruise, these airplanes could experience control problems. 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 September 5, 1995.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 5, 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
[[Page 39632]]
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: G. Michael Collins, Aerospace
Engineer, Propulsion Branch, ANM-140S, FAA, Transport Airplane
Directorate, Seattle Aircraft Certification Office, 1601 Lind Avenue,
SW., Renton, Washington 98055-4056; telephone (206) 227-2689; fax (206)
227-1181.
SUPPLEMENTARY INFORMATION: A proposal to amend part 39 of the Federal
Aviation Regulations (14 CFR part 39) to include an airworthiness
directive (AD) that is applicable to certain Boeing Model 747 SP, SR, -
100, -200, and -300 series airplanes was published in the Federal
Register on March 30, 1995 (60 FR 16392). [A correction of the proposal
was published in the Federal Register on April 5, 1995 (60 FR 17385).]
That action proposed to require repetitive operational tests of the
reversible gearbox pneumatic drive unit (PDU) or the reversing air
motor PDU to ensure that the unit can restrain the thrust reverser
sleeve, and correction of any discrepancy found during the test.
Interested persons have been afforded an opportunity to participate
in the making of this amendment. Due consideration has been given to
the comments received.
Two commenters support the proposed rule.
One commenter requests an extension of the intervals for repeating
the operational tests from 2,000 flight hours to 2,200 flight hours so
that the tests can be performed during regularly scheduled maintenance
visits. The commenter indicates that it has performed the initial test
and one repetitive test on all of its aircraft, and no anomalies have
been found. The FAA does not concur. The FAA established the repetitive
test interval of 2,000 flight hours to provide an acceptable level of
safety and to allow the majority of affected operators to schedule the
tests during normal maintenance intervals at a maintenance base where
special equipment and trained maintenance personnel will be available,
if necessary. In addition, the interval is consistent with the interval
recommended by the manufacturer in the alert service bulletin cited in
this AD. However, under the provisions of paragraph (d) of the final
rule, operators may apply for the approval of an adjustment of the
compliance time if sufficient justification is presented to the FAA.
After careful review of the available data, including the comments
noted above, the FAA has determined that air safety and the public
interest require the adoption of the rule as proposed.
This AD is considered to be interim action until final action is
identified, at which time the FAA may consider additional rulemaking.
There are approximately 456 Model 747 SP, SR, -100, -200, and -300
series airplanes of the affected design in the worldwide fleet. The FAA
estimates that 173 airplanes of U.S. registry will be affected by this
AD, that it will take approximately 16 work hours per airplane to
accomplish the required actions, and that the average labor rate is $60
per work hour. Based on these figures, the total cost impact of the AD
on U.S. operators is estimated to be $166,080, or $960 per airplane.
The total 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.
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. App. 1354(a), 1421 and 1423; 49 U.S.C.
106(g); and 14 CFR 11.89.
39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
95-16-02 Boeing: Amendment 39-9321. Docket 95-NM-06-AD.
Applicability: Model 747 SP, SR, -100, -200, and -300 series
airplanes equipped with Pratt & Whitney Model JT9D series engines
(excluding Model JT9D-70 engines), 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) of this AD 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 ensure the integrity of the fail safe features of
the thrust reverser system, accomplish the following:
(a) Within 90 days after the effective date of this AD, perform
an operational test of the reversible gearbox pneumatic drive unit
(PDU) or the reversing air motor PDU to ensure that the unit can
restrain the thrust reverser sleeve, in accordance with Boeing Alert
Service Bulletin 747-78A2131, dated September 15, 1994. Repeat the
test thereafter at intervals not to exceed 2,000 flight hours.
(b) If any of the tests required by this AD cannot be
successfully performed, or if any discrepancy is found during those
tests, accomplish either paragraph (b)(1) or (b)(2) of this AD.
(1) Prior to further flight, correct the discrepancy found, in
accordance with Boeing Alert Service Bulletin 747-78A2131, dated
September 15, 1994. Or
(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.
(c) Within 30 days after performing each initial test required
by this AD, submit a report of the test results, both positive and
negative, to the FAA, Seattle Aircraft
[[Page 39633]]
Certification Office (ACO), ANM-100S, 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 Aircraft Certification
Office (ACO), 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.
(e) 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.
(f) The actions shall be done in accordance with Boeing Alert
Service Bulletin 747-78A2131, dated September 15, 1994. This
incorporation by reference was approved by the Director of the
Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part
51. 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 September 5, 1995.
Issued in Renton, Washington, on July 21, 1995.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 95-18435 Filed 8-2-95; 8:45 am]
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