[Federal Register Volume 63, Number 71 (Tuesday, April 14, 1998)]
[Proposed Rules]
[Pages 18164-18167]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-9753]
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-08-AD]
RIN 2120-AA64
Airworthiness Directives; Airbus Model A320 Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Notice of proposed rulemaking (NPRM).
-----------------------------------------------------------------------
SUMMARY: This document proposes the adoption of a new airworthiness
directive (AD) that is applicable to all Airbus Model A320 series
airplanes. This proposal would require repetitive inspections to detect
fatigue cracking in certain areas of the fuselage; and corrective
action, if necessary. This proposal also would provide for an optional
terminating action for the repetitive inspections. This proposal is
prompted by issuance of mandatory continuing airworthiness information
by a foreign civil airworthiness authority. The actions specified by
the proposed AD are intended to detect and correct fatigue cracking of
the fuselage, which could result in reduced structural integrity of the
airplane.
DATES: Comments must be received by May 14, 1998.
[[Page 18165]]
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-08-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: Norman B. Martenson, Manager,
International Branch, ANM-116, FAA, Transport Airplane Directorate,
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (425)
227-2110; fax (425) 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 98-NM-08-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-114, Attention: Rules
Docket No. 98-NM-08-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, notified the FAA that an unsafe
condition may exist on all Airbus Model A320 series airplanes. The DGAC
advises that, during full-scale fatigue testing, cracking was detected
at flight cycles varying from 76,000 to 111,664 in several areas of the
fuselage:
On the bottom panel of the keel beam at the frame 46,
stringer 37 intersection at the pressure bulkhead;
On the outboard flanges of frames 38 through 41, between
stringers 12 and 21, originating at the fastener holes; and
On the upper rivet row on the outer skin panel of the
longitudinal lap joint, between frames 53 and 54, in the area of
stringer 6; and between frames 48 and 64.
Such fatigue cracking, if not detected and corrected in a timely
manner, could result in reduced structural integrity of the airplane.
Explanation of Relevant Service Information
Airbus has issued Service Bulletin A320-53-1034, dated March 30,
1992, which describes procedures for repetitive ultrasonic inspections
to detect cracking in the bottom panels of the keel beam (both left and
right), in the area of the frame 46 and stringer 37 intersection at the
pressure bulkhead; and repair, if necessary.
Airbus also has issued Service Bulletin A320-53-1033, Revision 3,
dated July 4, 1994, which describes procedures for modification of six
specific fastener holes in the area of the frame 46 and stringer 37
intersection. This modification involves removing existing fasteners;
cleaning the fastener holes; performing an eddy current inspection of
the fastener holes to detect cracking, and repairing cracking if
necessary; cold expanding the crack-free fastener holes; and installing
oversize fasteners. Accomplishment of this modification would eliminate
the need for the repetitive inspections specified in Airbus Service
Bulletin A320-53-1034.
Airbus also has issued Service Bulletin A320-53-1032, Revision 1,
dated January 15, 1998, which describes procedures for repetitive
visual inspections to detect cracking on the outboard flanges around
the fastener holes of frames 38 to 41, between stringers 12 and 21; and
repair, if necessary.
Airbus also has issued Service Bulletin A320-53-1031, dated
December 9, 1994, which describes procedures for modification of frames
38 to 41, between stringers 12 and 21. This modification involves cold
expanding fastener holes and replacing the existing fasteners with new
fasteners. Accomplishment of this modification, if performed prior to
the accumulation of 20,000 total flight cycles, would eliminate the
need for the repetitive inspections specified in Airbus Service
Bulletin A320-53-1032.
Airbus also has issued Service Bulletin A320-53-1057, Revision 2,
dated July 5, 1996, which describes procedures for repetitive visual or
eddy current inspections to detect cracking in the upper rivet row of
the outer skin panel of the longitudinal lap joints in four specific
areas; and repair, if necessary. The following areas are to be
inspected:
Between frames 48 and 64, next to stringer 6, on the left-
and right-hand sides of the fuselage;
Between frames 60 and 64, next to stringer 32, on the
left-hand side of the fuselage;
Between frames 59 and 64, next to stringer 32, on the
right-hand side of the fuselage; and
Between frames 58 and 64, next to stringer 41, on the
right-hand side of the fuselage.
Airbus also has issued Service Bulletin A320-53-1056, Revision 02,
dated February 16, 1998, which describes procedures for modification of
the outer skin panel of the longitudinal lap joints in multiple areas
of the rear fuselage. This modification involves measuring the
protrusion of existing rivets in the upper rivet rows of the
longitudinal lap joints; and replacing existing rivets with repair
rivets, if necessary. Accomplishment of this modification, if performed
prior to the accumulation of 20,000 total flight cycles, would
eliminate the need for the repetitive inspections specified in Airbus
Service Bulletin A320-53-1057.
Accomplishment of the modifications specified in Airbus Service
Bulletins A320-53-1033, A320-53-1031, and A320-53-1056 is intended to
adequately address the identified unsafe condition.
The DGAC classified Airbus Service Bulletins A320-53-1034, A320-53-
1032, and A320-53-1057 as mandatory and issued French airworthiness
directives 97-314-108(B), 97-313-107(B), and 97-312-106(B), all dated
October 22, 1997, in order to assure the
[[Page 18166]]
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 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 accomplishment of
the actions specified in Airbus Service Bulletins A320-53-1034, A320-
53-1032, and A320-53-1057, described previously, except as discussed in
the paragraphs that explain differences between this proposed rule and
the service bulletins (below). In addition, this proposed AD would
provide for optional terminating action for the repetitive inspections.
Operators should note that, in consonance with the findings of the
DGAC, the FAA has determined that the repetitive inspections proposed
by this AD can be allowed to continue in lieu of accomplishment of a
terminating action. In making this determination, the FAA considers
that, in this case, long-term continued operational safety will be
adequately assured by accomplishing the repetitive inspections to
detect cracking before it represents a hazard to the airplane.
Differences Between Proposed Rule and Service Bulletins
Operators should note that, unlike the procedures described in
Airbus Service Bulletins A320-53-1034, A320-53-1032, and A320-53-1057,
this proposed AD would not permit further flight if cracking is
detected in any section of the fuselage. The FAA has determined that,
because of the safety implications and consequences associated with
such cracking, any portion of the fuselage that is found to be cracked
must be repaired or modified prior to further flight, in accordance
with the applicable service bulletin, except as discussed in the next
paragraph.
Operators also should note that, although Airbus Service Bulletins
A320-53-1034, A320-53-1033, and A320-53-1032 specify that the
manufacturer may be contacted for disposition of certain repair
conditions, this proposed AD would require the repair of those
conditions to be accomplished in accordance with a method approved by
the FAA.
Cost Impact
The FAA estimates that 118 airplanes of U.S. registry would be
affected by this proposed AD.
It would take approximately 6 work hours per airplane to accomplish
the proposed ultrasonic inspection, at an average labor rate of $60 per
work hour. Based on these figures, the cost impact of the ultrasonic
inspection proposed by this AD on U.S. operators is estimated to be
$42,480, or $360 per airplane, per inspection cycle.
It would take approximately 19 work hours per airplane to
accomplish the proposed visual inspection on the outboard flanges, at
an average labor rate of $60 per work hour. Based on these figures, the
cost impact of the visual inspection proposed by this AD on U.S.
operators is estimated to be $134,520, or $1,140 per airplane, per
inspection cycle.
It would take approximately 15 work hours per airplane to
accomplish either the visual or eddy current inspection of the
longitudinal lap joints, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of these inspections proposed
by this AD on U.S. operators is estimated to be $106,200, or $900 per
airplane, per inspection cycle.
The cost impact figures discussed above are 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 terminating
action specified in Airbus Service Bulletin A320-53-1033 that would be
provided by this AD action, it would take approximately 5 work hours to
accomplish it, at an average labor rate of $60 per work hour. The cost
of required parts would be approximately $72 per airplane. Based on
these figures, the cost impact of that optional terminating action
would be $372 per airplane.
Should an operator elect to accomplish the optional terminating
action specified in Airbus Service Bulletin A320-53-1031 that would be
provided by this AD action, it would take approximately 1 work hour
(excluding access and closeup) per fastener hole to accomplish it, at
an average labor rate of $60 per work hour. The cost of required parts
would be approximately $4,047 (for one modification kit). Based on
these figures, the cost impact of that optional terminating action
would be a minimum of $4,107 per airplane.
Should an operator elect to accomplish the optional terminating
action specified in Airbus Service Bulletin A320-53-1056 that would be
provided by this AD action, it would take approximately 258 work hours
to accomplish it, at an average labor rate of $60 per work hour. The
cost of required parts would be approximately $420 per airplane. Based
on these figures, the cost impact of that optional terminating action
would be $15,900 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:
[[Page 18167]]
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 Industrie: Docket 98-NM-08-AD.
Applicability: All Model A320 series airplanes, 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 (h) 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 detect and correct fatigue cracking of the fuselage, which
could result in reduced structural integrity of the airplane,
accomplish the following:
(a) For airplanes on which Airbus Modification 21202 (reference
Airbus Service Bulletin A320-53-1033, Revision 3, dated July 4,
1994) has not been accomplished: Prior to the accumulation of 30,000
total flight cycles, or within 6 months after the effective date of
this AD, whichever occurs later, perform an ultrasonic inspection to
detect cracking in the bottom panels of the keel beam (both left and
right), in the area of the frame 46 and stringer 37 intersection at
the pressure bulkhead, in accordance with Airbus Service Bulletin
A320-53-1034, dated March 30, 1992. Thereafter, repeat the
ultrasonic inspection at intervals not to exceed 6,000 flight
cycles. If any crack is found, prior to further flight, repair in
accordance with the service bulletin, except as provided by
paragraph (g) of this AD.
(b) Accomplishment of Airbus Modification 21202 in accordance
with Airbus Service Bulletin A320-53-1033, Revision 3, dated July 4,
1994, constitutes terminating action for the repetitive inspection
requirement of paragraph (a) of this AD.
(c) For airplanes on which Airbus Modification 21346 (reference
Airbus Service Bulletin A320-53-1031, dated December 9, 1994) has
not been accomplished prior to the accumulation of 20,000 total
flight cycles: Prior to the accumulation of 30,000 total flight
cycles, or within 6 months after the effective date of this AD,
whichever occurs later, perform a visual inspection to detect
cracking on the outboard flanges around the fastener holes of frames
38 to 41, between stringers 12 and 21, in accordance with Airbus
Service Bulletin A320-53-1032, Revision 1, dated January 15, 1998.
Thereafter, repeat the visual inspection at intervals not to exceed
6,000 flight cycles. If any crack is found, prior to further flight,
repair in accordance with the service bulletin, except as provided
by paragraph (g) of this AD. Accomplishment of a repair in
accordance with the service bulletin terminates the repetitive
inspection requirements for the area repaired.
(d) Accomplishment of Airbus Modification 21346 in accordance
with Airbus Service Bulletin A320-53-1031, dated December 9, 1994,
prior to the accumulation of 20,000 total flight cycles constitutes
terminating action for the repetitive inspection requirement of
paragraph (c) of this AD.
(e) For airplanes on which Airbus Modification 21905 (reference
Airbus Service Bulletin A320-53-1056, Revision 02, dated February
16, 1998) has not been accomplished: Prior to the accumulation of
20,000 total flight cycles, or within 6 months after the effective
date of this AD, whichever occurs later, perform a visual or eddy
current inspection to detect cracking in the upper rivet row of the
longitudinal lap joint, in accordance with Airbus Service Bulletin
A320-53-1057, Revision 2, dated July 5, 1996.
(1) Thereafter, repeat the inspection at one of the following
intervals:
(i) If the immediately preceding inspection was conducted using
visual techniques, conduct the next inspection within 4,000 flight
cycles.
(ii) If the immediately preceding inspection was conducted using
eddy current techniques, conduct the next inspection within 12,000
flight cycles.
(2) If any crack is found, prior to further flight, repair in
accordance with the service bulletin, except as provided by
paragraph (g) of this AD. Accomplishment of a repair in accordance
with the service bulletin terminates the repetitive inspection
requirements for the area repaired.
(f) Accomplishment of Airbus Modification 21905 in accordance
with Airbus Service Bulletin A320-53-1056, Revision 02, dated
February 16, 1998, prior to the accumulation of 20,000 total flight
cycles constitutes terminating action for the repetitive inspection
requirements specified in paragraph (e)(1) of this AD.
(g) If any crack is found during any inspection required by
paragraph (a), (c), or (e) of this AD, and the applicable service
bulletin specifies to contact Airbus for appropriate action: Prior
to further flight, repair in accordance with a method approved by
the Manager, International Branch, ANM-116, FAA, Transport Airplane
Directorate.
(h) 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, International Branch, ANM-116.
Operators shall submit their requests through an appropriate FAA
Principal Maintenance Inspector, who may add comments and then send
it to the Manager, International Branch, ANM-116.
Note 2: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the International Branch, ANM-116.
(i) 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.
Note 3: The subject of this AD is addressed in French
airworthiness directives 97-314-108(B), 97-313-107(B), and 97-312-
106(B), all dated October 22, 1997.
Issued in Renton, Washington, on April 7, 1998.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 98-9753 Filed 4-13-98; 8:45 am]
BILLING CODE 4910-13-P
