[Federal Register Volume 64, Number 12 (Wednesday, January 20, 1999)]
[Proposed Rules]
[Pages 3052-3055]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-1182]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 98-NM-219-AD]
RIN 2120-AA64
Airworthiness Directives; Construcciones Aeronauticas, S.A.
(CASA) Model CN-235 Series Airplanes
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 CASA Model CN-235 series
airplanes. This proposal would require a one-time visual inspection to
detect relative movement or deformation of the joint areas of the rear
attaching supports and lower skin of the left and right outer flaps;
repetitive borescopic inspections to detect cracking of the spar and of
the
[[Page 3053]]
rear internal support fittings of the outer flaps; and corrective
actions, if necessary. This proposal also provides for 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 rear internal support fittings of the outer flap structure, which
could result in failure of the outer flaps, and consequent reduced
controllability of the airplane.
DATES: Comments must be received by February 19, 1999.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Transport Airplane Directorate, ANM-114,
Attention: Rules Docket No. 98-NM-219-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 Construcciones Aeronauticas, S.A., Getafe, Madrid, Spain.
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-219-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-219-AD, 1601 Lind Avenue, SW., Renton, Washington
98055-4056.
Discussion
The Direccion General de Aviacion Civil (DGAC), which is the
airworthiness authority for Spain, notified the FAA that an unsafe
condition may exist on certain CASA Model CN-235 series airplanes. The
DGAC advises that, during routine maintenance on a Model CN-235 series
airplane with a high number of flight cycles, relative displacement
between the lower skin of the outer flap and the outer rear fittings of
the outer flap was detected. Further inspection revealed that fatigue
cracking had developed in the rear internal support fittings of the
outer flap, which attaches the flap structure to the outer rear support
fittings. Such fatigue cracking, if not detected and corrected, could
result in failure of the outer flaps, and consequent reduced
controllability of the airplane.
Explanation of Relevant Service Information
CASA has issued Maintenance Instructions COM 235-123, Revision 01,
dated October 7, 1997, which describes procedures for a one-time
detailed visual inspection to detect relative movement or deformation
of the joint areas of the rear attaching supports and lower skin of the
left and right outer flaps, and repetitive borescopic inspections to
detect cracking of the spar and of the rear internal support fittings
of the outer flaps.
CASA also has issued Service Bulletin SB-235-57-20, dated December
23, 1997, which describes procedures for replacement of the left and
right outer flaps with new, improved outer flaps that have modified
rear internal support fittings installed. Accomplishment of this action
will eliminate the need for the repetitive borescopic inspections of
the replaced outer flap only, as described in CASA Maintenance
Instructions COM 235-123, Revision 01, dated October 7, 1997.
Accomplishment of the actions specified in CASA Maintenance
Instructions COM 235-123, Revision 01, and CASA Service Bulletin SB-
235-57-20, is intended to adequately address the identified unsafe
condition.
The DGAC classified the CASA Maintenance Instructions COM 235-123,
Revision 01, as mandatory and issued Spanish airworthiness directive
10/97, dated March 19, 1997, to assure the continued airworthiness of
these airplanes in Spain.
FAA's Conclusions
This airplane model is manufactured in Spain 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 the maintenance instructions and the service
bulletin described previously, except as discussed below.
Differences Between Proposed Rule and Related Service Information
Operators should note that, although the parallel Spanish
airworthiness directive does not mandate the accomplishment of required
actions for CASA Model CN-235 series airplanes, serial number C-011,
the applicability of this proposed AD would include that airplane.
Although that airplane was not certificated for civilian operation by
the DGAC, the FAA has certificated it as such. The FAA has determined
that the unsafe condition addressed in this AD may also exist or
develop on that airplane.
The proposed AD also would differ from the Spanish airworthiness
directive in that the latter document requires accomplishing the
following actions prior to the accumulation of 4,000 total landings:
[[Page 3054]]
A detailed visual inspection within 24 hours (after the
receipt of the Spanish airworthiness directive); and
A borescopic inspection within 10 days; and
Repetitive borescopic inspections for any outer flap
replaced with a new, improved outer flap within 4,000 landings and
thereafter at intervals not to exceed 600 landings.
In developing appropriate compliance times and repetitive intervals
for this proposed AD, the FAA considered not only the manufacturer's
recommendation, but the degree of urgency associated with addressing
the subject unsafe condition, the average utilization of the affected
fleet, and the time necessary to perform the visual inspection. In
light of all of these factors, the FAA finds the following to be
warranted prior to the accumulation of 4,000 total landings:
A one-time detailed visual inspection within 30 days after
the effective date of the AD; and
If no relative movement or deformation is detected, a
borescopic inspection within 300 landings after accomplishment of the
visual inspection; and
No repetitive inspections of an outer flap that is
replaced with a new, improved outer flap.
Operators should further note that, although CASA Maintenance
Instructions COM 235-123, Revision 01, dated October 7, 1997, specify
that the manufacturer may be contacted for disposition of certain
cracking conditions, this proposed AD would require addressing those
conditions by replacement of the outer flap with a new, improved outer
flap in accordance with CASA Service Bulletin SB-235-57-20, dated
December 23, 1997.
Cost Impact
The FAA estimates that 2 airplanes of U.S. registry would be
affected by this proposed AD, that it would take approximately 1 work
hour per airplane to accomplish the proposed visual inspection, 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 $120, or $60 per airplane.
It would take approximately 4 work hours to accomplish the proposed
borescopic inspection, at an average labor rate of $60 per work hour.
Based on these figures, the cost impact of the borescopic inspection
proposed by this AD on U.S. operators is estimated to be $480, or $240
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 terminating action that
is provided by this AD action, it would take approximately 30 work
hours to accomplish, at an average labor rate of $60 per work hour. The
cost of required parts would be approximately $123,204 per airplane.
Based on these figures, the cost impact of the optional terminating
action would be $125,004 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:
Construcciones Aeronauticas, S.A. (CASA): Docket 98-NM-219-AD.
Applicability: Model CN-235 series airplanes, as listed in CASA
Service Bulletin SB-235-57-20, dated December 23, 1997; and Model
CN-235 having serial number C-011; 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 (e) 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 rear internal
support fittings of the outer flap structure, which could result in
failure of the outer flaps, and consequent reduced controllability
of the airplane, accomplish the following:
(a) Prior to the accumulation of 4,000 total landings, or within
30 days after the effective date of this AD, whichever occurs later,
perform a one-time detailed visual inspection to detect relative
movement or deformation of the joint areas of the rear attaching
supports and lower skin of the left and right outer flaps, in
accordance with CASA Maintenance Instructions COM 235-123, Revision
01, dated October 7, 1997.
(1) If no relative movement or deformation is detected: Within
300 landings, perform the requirements of paragraph (b) of this AD.
(2) If any relative movement or deformation is detected: Prior
to further flight, perform the requirements of paragraph (b) of this
AD.
(b) Remove the rear support attach bolts, one at a time, and
perform a borescopic inspection to detect cracking of the spar and
of the rear internal support fittings of the outer flaps, in
accordance with CASA Maintenance Instructions COM 235-123, Revision
01, dated October 7, 1997.
(1) If no crack is detected, repeat the borescopic inspection
thereafter at intervals not to exceed 600 landings until the
replacement specified in paragraph (c) of this AD is accomplished.
(2) If any crack is detected, prior to further flight, replace
the cracked outer flap with a new outer flap on which modified rear
internal support fittings are installed, in accordance with CASA
Service Bulletin SB-235-57-20, dated December 23, 1997. Such
replacement constitutes terminating action for the repetitive
borescopic inspection required by paragraph (b) of this AD for the
replaced outer flap only.
[[Page 3055]]
(c) Accomplishment of the replacement specified in CASA Service
Bulletin SB-235-57-20, dated December 23, 1997, constitutes
terminating action for the repetitive borescopic inspections
required by paragraph (b) of this AD.
(d) As of the effective date of this AD, no person shall install
on any airplane an outer flap having part number 35-15501-00.
(e) 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, 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, 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.
(f) 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 Spanish
airworthiness directive 01/97, dated March 19, 1997.
Issued in Renton, Washington, on January 12, 1999.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 99-1182 Filed 1-19-99; 8:45 am]
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