[Federal Register Volume 62, Number 32 (Tuesday, February 18, 1997)]
[Proposed Rules]
[Pages 7184-7186]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-3840]
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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39
[Docket No. 96-NM-64-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A310 and A300-600 Series
Airplanes Equipped with Pratt & Whitney Turbofan 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 A310 and
A300-600 series airplanes. This proposal would require flow checks of
the hydraulic pump drain system to ensure that the system is not
clogged, and correction of any discrepancy. Additionally, the proposed
AD would require replacement of the existing seal of the accessory
gearbox with a new, improved seal assembly; this replacement would
terminate the requirement for repetitive flow checks. This proposal is
prompted by reports indicating that hydraulic fluid had contaminated
the engine oil system as a result of failure of the seal of the
hydraulic pump shaft. The actions specified by the proposed AD are
intended to prevent clogging of the hydraulic pump drain system, which
could cause failure of the seal of the hydraulic pump shaft and
subsequent contamination of the engine accessory gearbox oil; this
condition could result in an in-flight engine shutdown.
DATES: Comments must be received by March 28, 1997.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 96-NM-64-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: Tim Backman, Aerospace Engineer,
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206)
227-2797; 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 96-NM-64-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. 96-NM-64-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 A310 and A300-600
series airplanes. The DGAC advises that it has received reports of
engine oil contamination on both of these models of airplanes.
Investigation revealed that the contamination was due to failure of the
seal of the green hydraulic pump shaft as a result of clogging of the
hydraulic pump drain system. The seal is insufficient to handle the
increase in the backflow pressure when the hydraulic pump drain system
is clogged. Failure of the seal of the green hydraulic pump shaft, if
not corrected, could permit contamination of the engine accessory
gearbox oil, and result in an in-flight engine shutdown.
Explanation of Relevant Service Information
Airbus has issued the following service bulletins which describe
procedures for performing repetitive flow checks of the hydraulic pump
drain system to ensure that the system is not clogged, and correction
of any discrepancy.
1. For Model A310 series airplanes: Airbus Service Bulletin A310-
72-2022, dated February 16, 1993 (for airplanes on which Pratt &
Whitney JT9D-7R4D1 and 7R4E1 engines are installed); and Airbus Service
Bulletin A310-72-2023, Revision 1, dated December 22, 1993 (for
airplanes on which Pratt & Whitney PW4152 and PW 4156A engines are
installed).
2. For Model A300-600 series airplanes: Airbus Service Bulletin
A300-72-6018, Revision 1, dated December 22, 1993 (for airplanes on
which Pratt & Whitney JT9D-7R4H1 engines are installed); and Airbus
Service Bulletin A300-72-6019, Revision 1, dated December 22, 1993 (for
airplanes on which Pratt & Whitney PW4158 engines are installed).
[[Page 7185]]
Additionally, Airbus has issued the following service bulletins
which describe procedures to replace the existing carbon seal of the
accessory gearbox with a new, improved seal assembly that is capable of
withstanding a higher backflow pressure. This new seal assembly will
prevent hydraulic fluid leakage into the gearbox, and will eliminate
the need to perform repetitive flow checks.
1. For Model A300-600 series airplanes: Airbus Service Bulletin
A300-72-6014, dated March 15, 1993 (for airplanes on which Pratt &
Whitney PW JT9D-7R4H1 engines are installed); and Airbus Service
Bulletin A300-72-6015, Revision 2, dated December 22, 1993 (for
airplanes on which Pratt & Whitney PW4158 engines are installed).
2. For Model A310 series airplanes: Airbus Service Bulletin A310-
72-2018, Revision 2, dated December 22, 1993 (for airplanes on which
Pratt & Whitney PW JT9D-7R4D1 and -7R4E1 engines are installed); and
Airbus Service Bulletin A310-72-2019, Revision 2, dated December 22,
1993 (for airplanes on which Pratt & Whitney PW4152 and PW 4156A
engines are installed).
The DGAC classified these service bulletins and previous editions
of these service bulletins as mandatory and issued French airworthiness
directive 92-231-136(B)R2, dated October 13, 1993, in order to assure
the continued airworthiness of these airplanes in France.
FAA's Conclusions
These airplane models are manufactured in France and are type
certificated for operation in the United States under the provisions of
Sec. 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 these type designs that are
certificated for operation in the United States.
Explanation of Requirements of Proposed Rule
Since an unsafe condition has been identified that is likely to
exist or develop on other airplanes of the same type design registered
in the United States, the proposed AD would require repetitive flow
checks of the hydraulic pump drain system to ensure that the system is
not clogged, and correction of any discrepancy. Additionally, the
proposed AD would require replacement of the existing seal of the
accessory gearbox with a new, improved seal assembly. This replacement,
when accomplished, would provide terminating action for the repetitive
flow checks. The actions would be required to be accomplished in
accordance with the service bulletins described previously.
Cost Impact
The FAA estimates that 3 Airbus Model A300-600 and A310 series
airplanes of U.S. registry would be affected by this proposed AD. It
would take approximately 3 work hours per airplane to accomplish the
proposed one-time inspection, at an average labor rate of $60 per work
hour. It would take approximately 10 work hours per airplane to
accomplish the proposed terminating modification, at an average labor
rate of $60 per work hour. Required parts would cost approximately
$1,500 per airplane. Based on these figures, the cost impact of the
proposed AD on U.S. operators is estimated to be $6,840, or $2,280 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 U.S.C. 106(g), 40113, 44701.
Sec. 39.13 [Amended]
2. Section 39.13 is amended by adding the following new
airworthiness directive:
Airbus: Docket 96-NM-64-AD.
Applicability: Model A300B4-620, -622, -622R, and A300C4-620;
and Model A310-221, -222, -322, -324, and -325 series airplanes;
equipped with Pratt & Whitney turbofan engines; on which Airbus
Modification 10399 or 10400 has not 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 (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 prevent clogging of the hydraulic pump drain system, which
could cause failure of the seal of the hydraulic pump shaft and
subsequent contamination of the engine accessory gearbox oil, and
could result in an in-flight engine shutdown, accomplish the
following:
(a) Within 30 days after the effective date of this AD, perform
a flow check of the hydraulic pump drain system to ensure that it is
not clogged and, prior to further flight, correct any discrepancies,
in accordance with either paragraph (a)(1) or (a)(2) of this AD, as
applicable. Repeat the flow check, thereafter, at intervals not to
exceed 500 flight hours until the modification required by paragraph
(b) of this AD is accomplished.
(1) For Model A310 series airplanes: Perform the flow checks and
correct discrepancies in accordance with Airbus Service Bulletin
A310-72-2022, dated February 16, 1993 (for airplanes on which Pratt
& Whitney JT9D-7R4D1 and -7R4E1
[[Page 7186]]
engines are installed); or Airbus Service Bulletin A310-72-2023,
Revision 1, dated December 22, 1993 (for airplanes on which Pratt &
Whitney PW4152 and PW4156A engines are installed); as applicable.
Note 2: Flow checks accomplished prior to the effective date of
this AD in accordance with the original issuance of Airbus Service
Bulletin A310-72-2023 are considered acceptable for compliance with
the applicable action specified in this AD.
(2) For Model A300-600 series airplanes: Perform the flow checks
and correct discrepancies in accordance with Airbus Service Bulletin
A300-72-6018, Revision 1, dated December 22, 1993 (for airplanes on
which Pratt & Whitney JT9D-7R4H1 engines are installed); or Airbus
Service Bulletin A300-72-6019, Revision 1, dated December 22, 1993
(for airplanes on which Pratt & Whitney PW4158 engines are
installed); as applicable.
Note 3: Flow checks accomplished prior to the effective date of
this AD in accordance with the original issuance of Airbus Service
Bulletin A300-72-6018 or Airbus Service Bulletin A300-72-6019 are
considered acceptable for compliance with the applicable action
specified in this AD.
(b) Within 12 months after the effective date of this AD,
replace (on both engines) the existing seal of the green hydraulic
system gearbox with a new, improved seal assembly in accordance with
either paragraph (b)(1) or (b)(2) of this AD, as applicable.
Accomplishment of this replacement terminates the repetitive flow
check requirements for this AD.
(1) For Model A310 series airplanes: Accomplish the replacement
in accordance with Airbus Service Bulletin A310-72-2018, Revision 2,
dated December 22, 1993 (for airplanes on which Pratt & Whitney PW
JT9D-7R4D1 and -7R4E1 engines are installed); or Airbus Service
Bulletin A310-72-2019, Revision 2, dated December 22, 1993 (for
airplanes on which Pratt & Whitney PW4152 and PW4156A engines are
installed); as applicable.
Note 4: Replacement of the existing seal on the green hydraulic
system gearbox with a new, improved seal assembly accomplished prior
to the effective date of this AD, in accordance with the original
issuance or Revision 1 of Airbus Service Bulletin A310-72-2019, or
with the original issuance or Revision 1 of Airbus Service A310-72-
2018, is considered acceptable for compliance with the applicable
action specified in this AD.
(2) Model A300-600 series airplanes: Accomplish the replacement
in accordance with Airbus Service Bulletin A300-72-6014, dated March
15, 1993 (for airplanes on which Pratt & Whitney PW JT9D-7R4H1
engines are installed); or Airbus Service Bulletin A300-72-6015,
dated March 15, 1993 (for airplanes on which Pratt & Whitney PW4158
engines are installed); as applicable.
(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 5: 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.
Issued in Renton, Washington, on February 10, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 97-3840 Filed 2-14-97; 8:45 am]
BILLING CODE 4910-13-U
