[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]
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