[Federal Register Volume 61, Number 83 (Monday, April 29, 1996)]
[Proposed Rules]
[Pages 18699-18700]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-10509]
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DEPARTMENT OF AGRICULTURE
DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 95-NM-175-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A300-600 and A310 Series
Airplanes Equipped With General Electric Model CF6-80 Engines
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
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SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to certain Airbus Model A300-600 and
A310 series airplanes. This proposal would require an inspection to
detect defects of the directional pilot valves (DPV); and replacement
of any defective DPV with a new DPV, or deactivation of the thrust
reverser system, if necessary. This proposal is prompted by a report
indicating that, during a maintenance check, an uncommanded deployment
and stowage of the thrust reverser occurred due to improperly modified
DPV's. The actions specified by the proposed AD are intended to prevent
uncommanded deployment and stowage of the thrust reverser during
maintenance activities, as a result of improperly modified DPV's, which
could result in injury to maintenance personnel or other people on the
ground.
DATES: Comments must be received by June 10, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 95-NM-175-AD, 1601 Lind Avenue SW., Renton,
Washington 98055-4056. Comments may be inspected at this location
between 9:00 a.m. and 3:00 p.m., Monday through Friday, except Federal
holidays.
The service information referenced in the proposed rule may be
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707
Blagnac Cedex, France. This information may be examined at the FAA,
Transport Airplane Directorate, 1601 Lind Avenue SW., Renton,
Washington.
FOR FURTHER INFORMATION CONTACT: Charles Huber, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue SW., Renton, Washington 98055-4056; telephone (206)
227-2589; fax (206) 227-1149.
SUPPLEMENTARY INFORMATION:
Comments Invited
Interested persons are invited to participate in the making of the
proposed 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 above. All
communications received on or before the closing date for comments,
specified above, will be considered before taking action on the
proposed rule. The proposals contained in this notice may be changed in
light of the comments received.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the proposed 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 summarizing each FAA-public contact concerned with
the substance of this proposal will be filed in the Rules Docket.
Commenters wishing the FAA to acknowledge receipt of their comments
submitted in response to this notice must submit a self-addressed,
stamped postcard on which the following statement is made: ``Comments
to Docket Number 95-NM-175-AD.'' The postcard will be date stamped and
returned to the commenter.
Availability of NPRMs
Any person may obtain a copy of this NPRM by submitting a request
to the FAA, Transport Airplane Directorate, ANM-103, Attention: Rules
Docket No. 95-NM-175-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Direction Generale de l'Aviation Civile (DGAC), which is the
airworthiness authority for France, recently notified the FAA that an
unsafe condition may exist on certain Airbus Model A300-600 and A310
series airplanes, equipped with General Electric Model CF6-80 engines.
The DGAC advises that it has received a report indicating that, during
a maintenance check, an uncommanded deployment and stowage of the
thrust reverser occurred.
Investigation of this incident revealed that, when the thrust
reverser handle was moved from the ``stow'' position to the thrust
reverser test point, the directional pilot valve (DPV) stuck in the
``open'' (``deploy'') position. The air supply first caused the thrust
reverser to deploy, and then caused the DPV solenoid to move the DPV to
the ``stow'' direction, which resulted in the thrust reverser stowing.
This same sequence of events happened when the opposite engine was
tested. When both DPV's were replaced and a functional test carried
out, no anomaly was found. This indicated that the originally-installed
DPV's apparently were faulty.
Further tests carried out at the Airbus flight line on a General
Electric CF6-80C2 engine with the faulty DPV's installed, demonstrated
that deployment of the thrust reverser could not be reproduced with the
engine running. The thrust reverser deployment could be recreated only
with a progressive increase of ground air supply at low pressure
(approximately 10 to 15 psi) to the ground test point on the airplane.
When direct test pressure of 28 psi was applied to the DPV, the valve
reseated to the ``stow'' position. (This same scenario was confirmed by
bench testing performed by both General Electric and Allied Signal.)
Further investigation of the two faulty DPV's revealed that the
valves had been improperly modified when procedures specified in
General Electric Service Bulletin 78-031 had been accomplished on the
engine. The DPV armature spring had not been replaced with a new
stronger spring in accordance with the service bulletin instructions.
Accordingly, such an improperly modified DPV, if not corrected,
could result in uncommanded deployment and stowage of the thrust
reverser during maintenance activities, which consequently could cause
injury to maintenance personnel or other people on the ground.
[[Page 18700]]
Explanation of Relevant Service Information
Airbus has issued All Operators Telex (AOT) 78-05, Revision 01,
dated February 8, 1995, which describes procedures for a one-time
inspection to detect defects of the DPV; and replacement of the
defective DPV with a new DPV, or deactivation of the thrust reverser
system, if necessary. The DGAC classified this AOT as mandatory and
issued French airworthiness directive 95-052-176(B), dated March 15,
1995, in order to assure the continued airworthiness of these airplanes
in France.
FAA's Conclusions
This airplane model is manufactured in France and is type
certificated for operation in the United States under the provisions of
section 21.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. Pursuant to this
bilateral airworthiness agreement, the DGAC has kept the FAA informed
of the situation described above. The FAA has examined the findings of
the DGAC, reviewed all available information, and determined that AD
action is necessary for products of this type design that are
certificated for operation in the United States.
Explanation of the Requirements of the Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design, the
proposed AD would require a one-time inspection to detect defects of
the DPV. If a defective DPV is detected, it would be required to be
replaced with a new DPV, or thrust reverser system would be required to
be deactivated until the DPV is replaced. The inspection and
replacement actions would be required to be accomplished in accordance
with the AOT described previously.
Cost Impact
The FAA estimates that 43 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 10 work
hours per airplane to accomplish the proposed one-time inspection, and
that the average labor rate is $60 per work hour. Based on these
figures, the cost impact of the proposed AD on U.S. operators is
estimated to be $25,800, or $600 per airplane.
The cost impact figure discussed above is based on assumptions that
no operator has yet accomplished any of the proposed 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 proposed herein would 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
proposal would not have sufficient federalism implications to warrant
the preparation of a Federalism Assessment.
For the reasons discussed above, I certify that this proposed
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) if promulgated, 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 copy of the draft
regulatory evaluation prepared for this action is contained in the
Rules Docket. A copy of it may be obtained by contacting the Rules
Docket at the location provided under the caption ADDRESSES.
List of Subjects in 14 CFR Part 39
Air transportation, Aircraft, Aviation safety, Safety.
The Proposed Amendment
Accordingly, pursuant to the authority delegated to me by the
Administrator, the Federal Aviation Administration proposes to amend
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 USC 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Airbus Industrie: Docket 95-NM-175-AD.
Applicability: Model A300B4-601, -603, -605R, A300-F4-605R, and
A310-203, -203C, -204, -304, -308 series airplanes, equipped with
General Electric Model CF6-80 engines; on which General Electric
Service Bulletin 78-031 has been accomplished; certificated in any
category.
Note 1: This AD applies to each airplane identified in the
preceding applicability provision, regardless of whether it has been
otherwise 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 (b) 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 uncommanded deployment and stowage of the thrust
reverser during maintenance activities, accomplish the following:
(a) Within 600 flight hours after the effective date of this AD,
perform an inspection to detect defects of the directional pilot
valves (DPV) in accordance with Airbus All Operators Telex (AOT) 78-
05, Revision 01, February 8, 1995.
(1) If no defects are detected, no further action is required by
this AD.
(2) If any defect is detected, prior to further flight, either
replace the defective DPV with a new DPV in accordance with the AOT;
or deactivate the thrust reverser system in accordance with approved
procedures of the Minimum Equipment List (MEL) until the DPV is
replaced
(b) 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, Standardization Branch, ANM-113,
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,
Standardization Branch, ANM-113.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Standardization Branch, ANM-113.
(c) 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.
Issued in Renton, Washington, on April 23, 1996.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 96-10509 Filed 4-26-96; 8:45 am]
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