[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]
BILLING CODE 4910-13-P