[Federal Register Volume 64, Number 168 (Tuesday, August 31, 1999)]
[Rules and Regulations]
[Pages 47365-47368]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22193]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 99-NM-77-AD; Amendment 39-11269; AD 99-18-03]
RIN 2120-AA64
Airworthiness Directives; Boeing Model 747 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD),
applicable to certain Boeing Model 747 series airplanes. This action
requires repetitive inspections and tests of the thrust reverser
control and indication system on each engine, and corrective actions,
if necessary; installation of a terminating modification; and
repetitive operational checks of that installation, and repair, if
necessary. This amendment is prompted by the results of a safety
review, which revealed that in-flight deployment of a thrust reverser
could result in significant reduction in airplane controllability. The
actions specified in this AD are intended to ensure the integrity of
the fail-safe features of the thrust reverser system by preventing
possible failure modes, which could result in inadvertent deployment of
a thrust reverser during flight, and consequent reduced controllability
of the airplane.
DATES: Effective September 15, 1999.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of September 15, 1999.
Comments for inclusion in the Rules Docket must be received on or
before November 1, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 99-NM-77-AD, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056.
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 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: Ed Hormel, Aerospace Engineer,
Propulsion Branch, ANM-140S, FAA, Transport Airplane Directorate,
Seattle Aircraft Certification Office, 1601 Lind Avenue, SW., Renton,
Washington 98055-4056; telephone (206) 227-2681; fax (206) 227-1181.
SUPPLEMENTARY INFORMATION: On May 26, 1991, a Boeing Model 767-300ER
series airplane was involved in an accident as a result of an
uncommanded in-flight deployment of a thrust reverser. Following that
accident, a study was conducted to evaluate the potential effects of an
uncommanded thrust reverser deployment throughout the flight regime of
the Boeing Model 747 series airplane. The study included a re-
evaluation of the thrust reverser control system fault analysis and
airplane controllability. The results of the evaluation indicated that,
in the event of thrust reverser deployment during high-speed climb
using high engine power, these airplanes also could experience control
problems. This condition, if not corrected, could result in possible
failure modes in the thrust reverser control system, inadvertent
deployment of a thrust reverser during flight, and consequent reduced
controllability of the airplane.
Explanation of Relevant Service Information
The FAA has reviewed and approved Boeing Alert Service Bulletin
747-78A2148, dated June 1, 1995, and Boeing Service Bulletin 747-
78A2148, Revision 1, dated July 20, 1995, which describe procedures for
certain repetitive inspections and tests of the thrust reverser system,
and corrective actions, if necessary. The inspections and tests include
inspection of the thrust reverser control microswitch; a test of the
thrust reverser indication system; an integrity check of the number
three gear box lock and air motor brake; an inspection of the thrust
reverser wire bundle; and an operational test of the thrust reverser.
The corrective actions include, among other things:
Adjustment, or replacement and adjustment, of any
microswitch which fails to perform its intended function during
movement of the respective forward or reverse thrust lever.
Replacement of the number 3 gearbox lock or deactivation
of the thrust reverser on any engine if the thrust reverser translating
cowl moves when the number 3 gearbox lock should be engaged.
Replacement of the air motor on any engine if the thrust
reverser translating cowl moves when the air motor brake should be
engaged.
Replacement of worn or damaged wire clamps and wiring if
chafing or other damage is detected.
The FAA also has reviewed and approved Boeing Service Bulletin 747-
78-2136, dated May 11, 1995, which describes procedures for
installation of provisional wiring:
Between the P8 panel aisle stand and relay panels P252 and
P253;
Between the P6 overhead panel and relay panels P252 and
P253;
Between relay panels P252 and P253;
Between relay panels P252 and P253 and wing/body
disconnect area;
Between left wing/body disconnect area and strut No. 1 and
2; and
Between right wing/body disconnect area and strut No. 3
and 4.
This service bulletin references the Boeing Standard Wiring
Practices Manual, which describes wire installation procedures, and the
Boeing 747 Airplane Maintenance Manual (AMM) as additional sources of
service information for accomplishment of this modification.
In addition, the FAA has reviewed and approved Boeing Service
Bulletin 747-78-2156, dated October 31, 1996, which describes
procedures for installation of the following:
Four additional microswitches and associated wiring in the
aisle stand P8 panel;
Four circuit breakers and associated wiring changes in the
P6 panel;
New relay panels P252 and P253; and
Left and right wing/body disconnect panel and associated
wiring.
Boeing Service Bulletin 747-78-2156 references Boeing Service
Bulletin 747-78-2136; and the following Rolls-Royce Service Bulletins:
RB.211-71-B545, Revision 2, dated August 8, 1997, and
RB.211-71-B551, Revision 1, dated March 20, 1998, which describe
procedures for the installation of provisions on the engines to
accommodate the installation of an additional thrust reverser locking
gearbox; and
RB.211-78-B552, dated June 21, 1996, which describes
procedures for installation of an additional thrust reverser locking
gearbox.
Accomplishment of Boeing Service Bulletin 747-78-2156 requires
prior or
[[Page 47366]]
concurrent accomplishment of Boeing Service Bulletin 747-78-2136; and
Rolls-Royce Service Bulletins RB.211-71-B545, Revision 2; RB.211-71-
B551, Revision 1; and RB.211-78-B552, and eliminates the need for the
repetitive inspections and tests specified in Boeing Alert Service
Bulletin 747-78A2148, and Boeing Service Bulletin 747-78A2148, Revision
1.
Explanation of Requirements of the Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design, this AD is
being issued to prevent possible failure modes that can result in
inadvertent deployment of a thrust reverser during flight and
consequent reduced controllability of the airplane. This AD requires
repetitive inspections and tests of the thrust reverser system, and
corrective actions, if necessary; installation of a terminating
modification; and repetitive operational checks of the gearbox locks
and the air motor brake following accomplishment of the installation,
and repair, if necessary. The actions are required to be accomplished
in accordance with the service bulletins described previously, except
as discussed below.
This AD also includes a provision for deactivation of one thrust
reverser in accordance with Section 78-1 of Boeing Document D6-33391,
``Boeing 747-100/-200/-300/SP Dispatch Deviations Procedures Guide,''
Revision 22, dated January 30, 1998. No more than one reverser on any
airplane may be deactivated under the provisions of this document.
This AD also requires repetitive operational checks of the gearbox
locks and the air motor brake following accomplishment of Boeing
Service Bulletin 747-78-2156. Those checks are required to be performed
in accordance with the procedures described in Chapter 78-30-00,
Section 5, of the FAA-approved Boeing 747 Airplane Maintenance Manual
(AMM).
Differences Between Service Bulletins and This AD
Operators should note that, although Boeing Alert Service Bulletin
747-78A2148 and Boeing Service Bulletin 747-78A2148, Revision 1,
recommend accomplishing the initial inspection at the next convenient
maintenance period, the FAA has determined that such a compliance time
would not address the identified unsafe condition in a timely manner.
In developing an appropriate compliance time for this AD, the FAA
considered not only the manufacturer's recommendation, but the degree
of urgency associated with addressing the subject unsafe condition, the
average utilization of the affected fleet, and the time necessary to
perform the inspections (6 hours per engine). In light of all of these
factors, the FAA finds a 90-day compliance time for the initial
inspection to be warranted, in that it represents an appropriate
interval of time allowable for affected airplanes to continue to
operate without compromising safety.
Operators also should note that, although Boeing Service Bulletin
747-78-2156 does not specify any compliance time for accomplishment of
the modification, the FAA has determined that this does not address the
identified unsafe condition in a timely manner, as described above. The
FAA finds a 36-month compliance time for accomplishment of the
modification is warranted, in that it represents an appropriate
interval of time allowable for affected airplanes to continue to
operate without compromising safety.
Cost Impact
None of the Model 747 series airplanes affected by this action are
on the U.S. Register. All airplanes included in the applicability of
this rule currently are operated by non-U.S. operators under foreign
registry; therefore, they are not directly affected by this AD action.
However, the FAA considers that this rule is necessary to ensure that
the unsafe condition is addressed in the event that any of these
subject airplanes are imported and placed on the U.S. Register in the
future.
Should an affected airplane be imported and placed on the U.S.
Register in the future:
It would require approximately 24 work hours (6 work hours per
engine) to accomplish the required inspections and tests, at an average
labor rate of $60 per work hour. Based on these figures, the cost
impact of the inspections and tests required by this AD would be
approximately $1,440 per airplane, per inspection/test cycle.
It would require approximately 392 work hours to accomplish the
required installation of provisional wiring, at an average labor rate
of $60 per work hour. Required parts would cost approximately $22,298
per airplane. Based on these figures, the cost impact of this
modification required by this AD would be approximately $45,818 per
airplane.
It would require approximately 306 work hours to accomplish the
required installation of the locking gearbox, at an average labor rate
of $60 per work hour. Required parts would be provided by the
manufacturer at no cost to the operators. Based on these figures, the
cost impact of the installation required by this AD would be
approximately $18,360 per airplane.
It would require approximately 2 work hours to accomplish the
required operational check, at an average labor rate of $60 per work
hour. Based on these figures, the cost impact of the operational check
required by this AD would be approximately $120 per airplane, per
check.
Determination of Rule's Effective Date
Since this AD action does not affect any airplane that is currently
on the U.S. register, it has no adverse economic impact and imposes no
additional burden on any person. Therefore, prior notice and public
procedures hereon are unnecessary and the amendment may be made
effective in less than 30 days after publication in the Federal
Register.
Comments Invited
Although this action is in the form of a final rule and was not
preceded by notice and 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 99-NM-77-AD.'' The postcard will be date stamped and
returned to the commenter.
[[Page 47367]]
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 adding the following new
airworthiness directive:
99-18-03 Boeing: Amendment 39-11269. Docket 99-NM-77-AD.
Applicability: Model 747-100B, -200, -300, and SP series
airplanes, equipped with Rolls Royce RB211-524B2, C2, and D4
engines; certificated in any category, as listed in the following
service bulletins:
Boeing Alert Service Bulletin 747-78A2148, dated June
1, 1995;
Boeing Service Bulletin 747-78A2148, Revision 1, dated
July 20, 1995;
Boeing Service Bulletin 747-78-2136, dated May 11,
1995; and
Boeing Service Bulletin 747-78-2156, dated October 31,
1996.
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 prevent inadvertent deployment of a thrust reverser during
flight and consequent reduced controllability of the airplane,
accomplish the following:
Repetitive Inspections and Tests
(a) Within 90 days after the effective date of this AD: Perform
the applicable inspections and tests of the thrust reverser control
and indication system on each engine, in accordance with Part III.A.
through III.G. of the Accomplishment Instructions of Boeing Alert
Service Bulletin 747-78A2148, dated June 1, 1995, or Boeing Service
Bulletin 747-78A2148, Revision 1, dated July 20, 1995. Repeat the
applicable inspections and tests thereafter at intervals not to
exceed 18 months, until accomplishment of paragraph (c) of this AD.
Corrective Actions
(b) If any inspection or test required by paragraph (a) of this
AD cannot be successfully performed as specified in the service
bulletin, or if any discrepancy is detected during any inspection or
test, accomplish paragraphs (b)(1) and (b)(2) of this AD.
(1) Prior to further flight, deactivate the associated thrust
reverser in accordance with Section 78-1 of Boeing Document D6-
33391, ``Boeing 747-100/-200/-300/SP Dispatch Deviations Procedures
Guide,'' Revision 22, dated January 30, 1998. No more than one
reverser on any airplane may be deactivated under the provisions of
this paragraph.
Note 2: The airplane may be operated in accordance with the
provisions and limitations specified in the operator's FAA-approved
Master Minimum Equipment List (MMEL), provided that no more than one
thrust reverser on the airplane is inoperative.
(2) Within 10 days after deactivation of any thrust reverser in
accordance with this paragraph, the thrust reverser must be repaired
in accordance with Boeing Alert Service Bulletin 747-78A2148, dated
June 1, 1995, or Boeing Service Bulletin 767-78A2148, Revision 1,
dated July 20, 1995. Additionally, the inspections and tests
required by paragraph (a) of this AD must be successfully
accomplished as specified in the service bulletin; once this is
accomplished, the thrust reverser must then be reactivated.
Modification
(c) Within 36 months after the effective date of this AD,
install an additional locking system on the thrust reversers in
accordance with the Accomplishment Instructions of Boeing Service
Bulletin 747-78-2156, dated October 31, 1996. Prior to or concurrent
with accomplishment of Boeing Service Bulletin 747-78-2156, dated
October 31, 1996: Accomplish Boeing Service Bulletin 747-78-2136,
dated May 11, 1995; and Rolls-Royce Service Bulletins RB.211-71-
B545, Revision 2, dated August 8, 1997, RB.211-71-B551, Revision 1,
dated March 20, 1998, and RB.211-78-B552, dated June 21, 1996.
Accomplishment of these actions constitutes terminating action for
the repetitive inspections and tests required by paragraph (a) of
this AD.
Operational Checks
(d) Within 3,000 flight hours after accomplishing the
modification required by paragraph (c) of this AD, or within 1,000
flight hours after the effective date of this AD, whichever occurs
later: Perform operational checks of the number 2 and number 3
gearbox locks and of the air motor brake, in accordance with the
procedures described in Chapter 78-30-00, Section 5, of the FAA-
approved Boeing 747 Airplane Maintenance Manual (AMM).
Corrective Actions
(e) If any operational check required by paragraph (d) of this
AD cannot be successfully performed as specified in the procedures
described in Chapter 78-30-00, Section 5, of the AMM, or if any
discrepancy is detected during any operational check, accomplish
paragraphs (e)(1) and (e)(2) of this AD. Repeat the operational
checks thereafter at intervals not to exceed 3,000 flight hours.
(1) Prior to further flight, deactivate the associated thrust
reverser in accordance with Section 78-1 of Boeing Document D6-
33391, ``Boeing 747-100/-200/-300/SP Dispatch Deviations Procedures
Guide,'' Revision 22, dated January 30, 1998. No more than one
reverser on any airplane may be deactivated under the provisions of
this paragraph.
Note 3: The airplane may be operated in accordance with the
provisions and limitations specified in the operator's FAA-approved
MMEL, provided that no more than one thrust reverser on the airplane
is inoperative.
(2) Within 10 days after deactivation of any thrust reverser in
accordance with this paragraph, the thrust reverser must be repaired
in accordance the AMM. Additionally, the operational checks required
by paragraph (d) of this AD must be successfully accomplished as
specified in the AMM; once this is accomplished, the thrust reverser
must then be reactivated.
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 (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.
[[Page 47368]]
Note 4: 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 (b)(1), (d), (e), (e)(1),
and (e)(2) of this AD, the actions shall be done in accordance with
the applicable service bulletins, which contain the specified list
of effective pages:
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Service bulletin referenced Revision level shown
and date Page No. shown on page on page Date shown on page
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Boeing 747-78-2136, May 11, 1-161...................... Original.............. May 11, 1995.
1995.
Boeing 747-78A2148, June 1, 1-50....................... Original.............. June 1, 1995.
1995.
Boeing 747-78A2148, Revision 1-50....................... 1..................... July 20, 1995.
1, July 20, 1995.
Boeing 747-78-2156, October 1-283...................... Original.............. October 31, 1996.
31, 1996.
Rolls-Royce, RB.211-78-B552 1-33....................... Original.............. June 21, 1996.
June 21, 1996.
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Supplement
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1, 2....................... Original.............. June 21, 1996.
Rolls-Royce, RB.211-71-B545, 1, 4....................... 2..................... August 8, 1997.
Revision 2, August 8, 1997.
2, 3, 5-45................. Original.............. December 22, 1995.
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Supplement
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1, 2....................... 2..................... August 8, 1997.
Rolls-Royce, RB.211-71-B551, 1, 5, 85................... 1..................... March 20, 1998.
Revision 1, March 20, 1998.
2-4, 6-84, 86-106.......... Original.............. June 21, 1996.
Supplement
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1-5........................ 1..................... March 20, 1998.
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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.
(i) This amendment becomes effective on September 15, 1999.
Issued in Renton, Washington, on August 19, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-22193 Filed 8-30-99; 8:45 am]
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