[Federal Register Volume 61, Number 35 (Wednesday, February 21, 1996)]
[Rules and Regulations]
[Pages 6503-6505]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3262]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 95-NM-34-AD; Amendment 39-9517; AD 96-04-05]


Airworthiness Directives; Airbus Model A300-B2 and -B4 Series 
Airplanes Equipped with General Electric CF6-50 Series Engines or Pratt 
& Whitney JT9D-59A Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
is applicable to certain Airbus Model A300-B2 and -B4 series airplanes. 
This amendment requires an inspection to detect discrepancies of a 
certain thrust reverser control lever spring; an operational test to 
verify the integrity of the flight inhibition circuit of the thrust 
reverser system; and either the correction of discrepancies or 
deactivation of the associated thrust reverser. It also provides for an 
optional terminating action. This amendment is prompted by a report 
that, due to broken and deformed thrust reverser control lever springs, 
an uncommanded movement of the thrust reverser lever to the unlock 
position and a ``reverser unlock'' amber warning occurred on one 
airplane. The actions specified by this AD are intended to detect such 
broken or deformed control lever springs before they can lead to 
uncommanded deployment of a thrust reverser and subsequent reduced 
controllability of the airplane.

DATES: Effective March 22, 1996.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 22, 1996.

ADDRESSES: The service information referenced in this AD may be 
obtained from Airbus Industrie, 1 Rond Point Maurice Bellonte, 31707 
Blagnac Cedex, France. 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: 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: 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 Airbus Model A300-B2 and -
B4 series airplanes was published in the Federal Register on April 3, 
1995 (60 FR 16813). That action proposed to require a mechanical 
integrity inspection to detect discrepancies of the thrust reverser 
control lever spring having part number (P/N) A2791294520000, and an 
operational test to verify the integrity of the flight inhibition 
circuit of the thrust reverser system. It also requires the correction 
of discrepancies or deactivation of the associated thrust reverser.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.
    One commenter supports the proposed rule.
    One commenter notes that the Description section of the preamble to 
the notice states that ``* * * uncommanded movement of the thrust 
reverser lever to the unlock position and a `reverser unlock' amber 
warning occurred.'' The commenter suggests, to be consistent with the 
current industry definition, a more accurate description of what caused 
the unsafe condition is ``inadvertently commanded deployment [of the 
thrust reverser].'' The FAA does not concur. The FAA has reviewed the 
relevant data available, and finds no basis to support the commenter's 
suggestion that the thrust reverser was ``commanded'' to deploy. The 
FAA finds that the pilot did not command the thrust reverser to deploy, 
nor did the pilot inadvertently deploy the thrust reverser.
    Additionally, this commenter requests clarification of certain 
statements made in the Discussion section of the preamble to the 
notice. The commenter asks whether the reported incident occurred when 
the airplane was on the ground or in flight. The FAA concurs that some 
clarification is necessary. The incident occurred on the ground during 
a training flight where a simulated engine-out condition was performed. 
Since the Discussion section is not restated in this final rule, no 
change to the final rule is necessary as a result of this 
clarification.
    The same commenter requests that the proposed rule be revised to 
require repetitive inspections of the thrust reverser control lever 
spring, and a final corrective action. The commenter asserts that, 
since the notice indicates that the unsafe condition is ``* * * likely 
to develop'' on affected airplanes, it would seem reasonable to require 
replacement of the spring, regardless of the condition of the spring at 
the initial inspection. Additionally, until the spring is replaced, it 
should be repetitively inspected, since it is not clear if the root 
cause of the problem is a design or assembly defect, or if it is time-
related. The FAA concurs partially. 

[[Page 6504]]
Since issuance of the notice, Airbus has issued Service Bulletin A300-
78-0015, dated May 17, 1995, which describes procedures for replacement 
of the left and right control levers of the thrust reverser with a new 
control lever equipped with a new spring. The Direction Generale de 
l'Aviation Civile (DGAC), which is the airworthiness authority for 
France, approved this service bulletin. The FAA finds that the 
replacement specified in that service bulletin may be provided as an 
optional terminating action for the requirements of this final rule. 
Therefore, the FAA has added a new paragraph (b) to the final rule to 
provide for this option.
    Additionally, the FAA is considering additional rulemaking to 
require repetitive inspections of the thrust reverser lever spring, as 
well as to mandate the eventual replacement of the thrust reverser 
control lever with the new control lever. However, the planned 
compliance time for this repetitive inspection and replacement is 
sufficiently long so that notice and public comment will be 
practicable.
    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 with the changes previously 
described. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.
    The FAA estimates that 21 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 6 work hours per 
airplane to accomplish the required actions, and that the average labor 
rate is $60 per work hour. Required parts will cost approximately $55 
per airplane. Based on these figures, the cost impact of the AD on U.S. 
operators is estimated to be $8,715, or $415 per airplane.
    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.
    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:

96-04-05 Airbus Industrie: Amendment 39-9517. Docket 95-NM-34-AD.

    Applicability: Model A300-B2 and B-4 series airplanes, equipped 
with General Electric CF6-50 series engines or Pratt & Whitney JT9D-
59A 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 
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 (c) 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 detection of broken or deformed thrust reverser 
control lever springs that could lead to uncommanded deployment of a 
thrust reverser and subsequent reduced controllability of the 
airplane, accomplish the following:
    (a) Within 500 flight hours after the effective date of this AD, 
perform a mechanical integrity inspection to detect discrepancies of 
the thrust reverser control lever spring having part number (P/N) 
A2791294520000, and an operational test to verify the integrity of 
the flight inhibition circuit of the thrust reverser system, in 
accordance with Airbus All Operators Telex AOT 78-03, Revision 1, 
dated July 20, 1994.
    (1) If no discrepancies are detected, no further action is 
required by this AD.
    (2) If the control lever spring is found broken or out of 
tolerance, prior to further flight, replace it with a new control 
lever spring or deactivate the associated thrust reverser in 
accordance with the AOT.
    (3) If the flight inhibition circuit of the thrust reverser 
system fails the operational test, prior to further flight, 
determine the origin of the malfunction, in accordance with the AOT.
    (i) If the origin of the malfunction is identified, prior to 
further flight, repair the flight inhibition circuit in accordance 
with the AOT.
    (ii) If the origin of the malfunction is not identified, prior 
to further flight, replace the relay having P/N 125GB or 124GB, and 
repeat the operational test, in accordance with the AOT. If the 
malfunction is still present, prior to further flight, inspect and 
repair the wiring in accordance with the AOT. If the malfunction is 
still present following the inspection and repair, prior to further 
flight, deactivate the associated thrust reverser in accordance with 
the AOT.
    (b) Replacement of the left and right control levers of the 
thrust reverser with a new control lever equipped with a new spring, 
in accordance with Airbus Service Bulletin A300-78-0015, dated May 
17, 1995, constitutes terminating action for the requirements of 
this AD.
    (c) 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.

    (d) 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.
    (e) The actions shall be done in accordance with Airbus All 
Operators Telex AOT 78-03, Revision 1, dated July 20, 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 Airbus 

[[Page 6505]]
Industrie, 1 Rond Point Maurice Bellonte, 31707 Blagnac Cedex, France. 
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.
    (f) This amendment becomes effective on March 22, 1996.

    Issued in Renton, Washington, on February 8, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 96-3262 Filed 2-20-96; 8:45 am]
BILLING CODE 4910-13-P