[Federal Register Volume 61, Number 135 (Friday, July 12, 1996)]
[Proposed Rules]
[Pages 36664-36667]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-17741]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-NM-222-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A310 and A300-600 Series
Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Supplemental notice of proposed rulemaking; reopening of
comment period.
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SUMMARY: This document revises an earlier proposed airworthiness
directive (AD), applicable to certain Airbus Model A310 and A300-600
series airplanes, that would have required repetitive Tap Test
inspections to detect debonding of the elevator skins, and corrective
actions, if necessary. That proposal was prompted by a report that a
debonded area of the upper skin of an elevator had been discovered
during a visual inspection. This action revises the proposed rule by
replacing the Tap Test inspections with inspections using a
thermographic technique. This action also provides for replacement of
the elevators with new or modified elevators, which, if accomplished,
terminates the requirements of the AD. The actions specified by this
proposed AD are intended to prevent the presence of water in the
elevator, which could cause debonding of the elevator skins and,
consequently, could adversely affect the structural integrity of the
elevator.
DATES: Comments must be received by August 14, 1996.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-103,
Attention: Rules Docket No. 94-NM-222-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 94-NM-222-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. 94-NM-222-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
A proposal to amend part 39 of the Federal Aviation Regulations (14
CFR part 39) to add an airworthiness directive (AD), applicable to
certain Airbus Model A310 and A300-600 series airplanes, was published
as a notice of proposed rulemaking (NPRM) in the Federal Register on
February 8, 1995 (60 FR 7485). That NPRM would have required repetitive
Tap Test inspections to detect debonding of the elevator skins, and
corrective actions, if necessary. Additionally, that NPRM would have
required repetitive thermographic inspections of the elevator to detect
trapped water if certain amounts of debonding are detected. That NPRM
was prompted by
[[Page 36665]]
a report that a debonded area of the upper skin of an elevator had been
discovered during a visual inspection. That condition, if not
corrected, could result in the presence of water in the elevator, which
could cause debonding of the elevator skins and, consequently, could
adversely affect the structural integrity of the elevator.
Actions Since Issuance of Previous Proposal
Since the issuance of that NPRM, Airbus has issued Revision 1 of
Service Bulletins A310-55-2016 (for Model A310 series airplanes) and
A300-55-6014 (for Model A300-600 series airplanes), both dated August
8, 1995. The original issues of these service bulletins were cited in
the NPRM as the appropriate sources of service information for
accomplishment of repetitive thermographic inspections to detect water
in the elevator, and protection and repair of debonded areas of the
elevator. Revision 1 of the service bulletins is essentially the same
as the original issues, however, Revision 1 specifies an increased
allowable cosmetic repair area and introduces new repair criteria.
Additionally, Revision 1 provides a threshold and repeat intervals for
the thermographic inspections based on the specific types of elevators
that are installed.
The Direction Generale de l'Aviation Civile (DGAC), which is the
airworthiness authority for France, classified these service bulletins
as mandatory and issued French airworthiness directive (CN) 95-206-
189(B), dated October 25, 1995, in order to assure the continued
airworthiness of these airplanes in France. That French CN supersedes
the previously-issued French CN 94-184-157(B), dated August 17, 1994.
The new French CN removes a previous requirement for repetitive Tap
Test inspections and, instead, it requires thermographic inspections to
detect water trapped in the elevator. In addition, the new French CN
indicates that it applies to Model A310 and A300-600 series airplanes
that are equipped with certain carbon fiber elevators on which Airbus
Modifications 10489 and 10533 have not been accomplished.
Additionally, since the issuance of the NPRM, Airbus also has
issued Service Bulletins A310-55-2019 (for Model A310 series airplanes)
and A300-55-6016 (for Model A300-600 series airplanes), both Revision
1, both dated December 18, 1995. These service bulletins describe
procedures for replacement of existing elevators with new or modified
elevators. Installation of the new or modified elevators will prevent
water ingress by adding a second external layer of adhesive and using a
different type of Tedlar film. Such installation, if accomplished, will
eliminate the need for the repetitive thermographic inspections.
FAA's Conclusions
The FAA has examined the findings of the DGAC and has reviewed the
revised service information. The FAA finds that inspections using
thermographic techniques are a more reliable method of detecting water
trapped in the elevators. Therefore, the FAA has determined that the
NPRM must be revised to remove the requirement for repetitive Tap Test
inspections and to require, instead, the accomplishment of repetitive
thermographic inspections in accordance with the latest service
bulletin revisions.
Additionally, the FAA finds that the NPRM must be revised to
specify that the inspection threshold and repetitive inspection
intervals are based on the specific types of elevators that are
installed.
The FAA also finds that the NPRM must be revised to provide for
replacement of the elevators with new or modified elevators, which, if
accomplished, would terminate the repetitive thermographic inspections.
In addition, the applicability of the NPRM has been revised to
coincide with the applicability of French CN 95-206-189(B).
Since these changes expand the scope of the originally proposed
rule, the FAA has determined that it is necessary to reopen the comment
period to provide additional opportunity for public comment.
Type Certification of Affected Airplanes
These airplane models are manufactured in France and are type
certificated for operation in the United States under the provisions of
section 221.29 of the Federal Aviation Regulations (14 CFR 21.29) and
the applicable bilateral airworthiness agreement. and
Disposition of Comments to the NPRM
Interested persons were afforded an opportunity to respond to the
NPRM. Due consideration has been given to pertinent comments that were
submitted, as described below.
Request to Require Pulse-Echo Ultrasound Inspections
One commenter requests that the proposed Tap Tests, be replaced
with pulse-echo ultrasound (A-scan) inspections. The commenter states
that the pulse-echo ultrasound inspection is much more accurate than a
Tap Test.
The FAA concurs partially. The FAA acknowledges that more accurate
inspections for debonding may exist; however, the FAA does not agree
that pulse-echo ultrasound inspections are the type of inspections that
should be required in this case. In developing this AD, the FAA
considered the fact that pulse-echo ultrasound equipment and procedures
are not readily available to all operators. Additionally, the FAA
considered the accuracy of thermographic inspections, as well as the
accessibility of thermographic inspections to all operators. In
consideration of these items, the FAA finds that thermographic
inspections are most appropriate to address the unsafe condition.
However, under the provisions of paragraph (f) of the final rule, the
FAA may approve alternative methods of compliance with this AD if data
are submitted to substantiate that such a method would provide an
acceptable level of safety.
Request to Update Cost Impact Information
One commenter requests that the estimated number of affected U.S.-
registered airplanes specified in the cost impact information of the
proposed rule be revised from 15 to 35, since that is the number of
Model A300-600 series airplanes in its fleet.
The FAA concurs and has revised the cost impact information, below,
to reflect this change.
Cost Impact
There are approximately 137 Model A310 and A300-600 series
airplanes of the affected design in the worldwide fleet. The FAA
estimates that 35 airplanes of U.S. registry would be affected by this
proposed AD, that it would take approximately 34 work hours per
airplane to accomplish the proposed actions, 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 $71,400, or $2,040
per airplane, per inspection cycle.
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.
Should an operator elect to accomplish the optional replacement of
the elevators, it would take approximately 14 work hours per airplane
to accomplish the replacement, at an average labor rate of $60 per work
[[Page 36666]]
hour. The manufacturer would provide the replacement parts at no cost
to the operator. Based on these figures, the cost impact of the
optional replacement action is estimated to be $840 per airplane.
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 94-NM-222-AD.
Applicability: Model A310 and A300-600 series airplanes equipped
with carbon fiber elevators having part number (P/N) A5527605500000
(left-hand side) and P/N A5527605600000 (right-hand side), on which
Airbus Modifications 10489 and 10533 have 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
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 (f) 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 the presence of water in the elevator, which could
cause debonding of the elevator skins and, consequently, could
affect the structural integrity of the elevator, accomplish the
following:
(a) Perform a thermographic inspection to detect any water that
is trapped within the elevator structure, in accordance with either
Airbus Service Bulletin A310-55-2016, Revision 1, (for Model A310
series airplanes); or Airbus Service Bulletin A300-55-6014, Revision
1, (for Model A300-600 series airplanes), both dated August 8, 1995,
as applicable. Perform the inspection at the time specified in
paragraph (a)(1) or (a)(2) of this AD, as applicable.
(1) For airplanes on which CARCOM elevators are installed:
Perform the inspection at the later of the times specified in
paragraphs (a)(1)(i) and (a)(1)(ii) of this AD.
(i) Prior to the accumulation of 4,500 total landings on the
elevator, or within 5 years after the first landing on the elevator,
whichever occurs later; or
(ii) Within 3 months after the effective date of this AD.
(2) For airplanes on which CASA elevators are installed: Perform
the inspection at the later of the times specified in paragraphs
(a)(2)(i) and (a)(2)(ii) of this AD.
(i) Prior to the accumulation of 5,000 total landings on the
elevator, or within 6 years after the first landing on the elevator,
whichever occurs later.
(ii) Within 3 months after the effective date of this AD.
(b) If no water is detected, repeat the thermographic inspection
required by paragraph (a) of this AD thereafter at the time
specified in paragraph (b)(1) or (b)(2) of this AD, as applicable.
(1) For airplanes on which CARCOM elevators are installed:
Repeat the inspection at intervals not to exceed 4,500 landings or 5
years, whichever occurs first;
(2) For airplanes on which CASA elevators are installed: Repeat
the inspection at intervals not to exceed 5,000 landings or 6 years,
whichever occurs first.
(c) If any water is detected in the elevator, and the area is
within the limits specified in the Accomplishment Instructions of
either Airbus Service Bulletin A310-55-2016, Revision 1, (for Model
A310 series airplanes), or A300-55-6016 (for Model A300-600 series
airplanes), both Revision 1, both dated August 8, 1995, as
applicable: Prior to further flight, protect and/or repair the
elevator in accordance with the applicable service bulletin.
Thereafter, repeat the thermographic inspections required by
paragraph (b) of this AD at the times specified in the
Accomplishment Instructions of the applicable service bulletin until
the replacement of the elevator is accomplished as specified in
paragraph (e) of this AD.
(d) If any water is detected in the elevator that exceeds the
limits specified by Airbus Service Bulletin A310-55-2016 (for Model
A310 series airplanes), or Airbus Service Bulletin A300-55-6014 (for
Model A300-600 series airplanes), both Revision 1, and both dated
August 8, 1995, as applicable: Accomplish the requirements of either
(d)(1) or (d)(2) of this AD, as applicable.
(1) If any damage is detected that is less than or equal to
60,000 square millimeters or 93 square inches, prior to further
flight, protect or repair and perform repetitive inspections in
accordance with the applicable service bulletin.
(2) If any damage is detected that is more than 60,001 square
millimeters or 93 square inches, prior to further flight, perform
the requirements of either paragraph (d)(2)(i) or (d)(2)(ii) of this
AD.
(i) If the damage is within the limits of the Structural Repair
Manual (SRM) (Ref. SRM 55-20-00), accomplish the repair in
accordance with the SRM; or
(ii) Replace the elevator in accordance with Airbus Service
Bulletin A310-55-2019 (for Model A310 series airplanes), or A300-55-
6016 (for Model A300-600 series airplanes), both dated December 18,
1995. No further action is required by this AD.
(e) Replacement of the elevator in accordance with either Airbus
Service Bulletin A310-55-2019 (for Model A310 series airplanes), or
A300-55-6016 (for Model A300-600 series airplanes), both dated
December 18, 1995, as applicable, constitutes terminating action for
the requirements of this AD.
(f) 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.
(g) 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.
[[Page 36667]]
Issued in Renton, Washington, on July 8, 1996.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service. -
[FR Doc. 96-17741 Filed 7-11-96; 8:45 am]
BILLING CODE 4910-13-U
