[Federal Register Volume 62, Number 17 (Monday, January 27, 1997)]
[Proposed Rules]
[Pages 3834-3836]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1479]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-127-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 the replacement of the center 
wing attachment rods with new rods. This proposal is prompted by a 
report from the manufacturer indicating that these rods failed during a 
full-scale fatigue test. The actions specified by the proposed AD are 
intended to prevent fatigue failure of these rods, which consequently 
could reduce the structural integrity of the wing-to-fuselage 
attachment.

DATES: Comments must be received by March 3, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-127-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: Greg Dunn, Aerospace Engineer, 
Standardization Branch, ANM-113, FAA, Transport Airplane Directorate, 
1601 Lind Avenue, SW., Renton, Washington 98055-4056; telephone (206) 
227-2799; 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

[[Page 3835]]

Docket Number 96-NM-127-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-127-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direccion General de Aviacion (DGAC), which is the 
airworthiness authority for Spain, recently notified the FAA that an 
unsafe condition may exist on certain CASA Model CN-235 series 
airplanes. The DGAC advises that it has received a report from the 
manufacturer indicating that, during full-scale fatigue tests on the 
test model, the center wing attachment rods had failed at the joints 
where the center wing attaches to the fuselage; this failure occurred 
subsequent to 16,000 simulated landings. This condition, if not 
corrected, could reduce the structural integrity of the wing-to-
fuselage attachment.

Explanation of Relevant Service Information

    CASA has issued Service Bulletin SB-235-53-21M, Revision 1, dated 
November 21, 1994 (for military airplanes), and Service Bulletin SB-
235-53-21, Revision 3, dated November 30, 1994 (for non-military 
airplanes). These service documents describe procedures for replacement 
of center wing attachment rods having CASA part number (P/N) 35-22058-
0003 or 35-22067-0001 with new rods having CASA P/N 35-22067-0003.
    The DGAC classified CASA Service Bulletin SB-235-53-21 as mandatory 
and issued Spanish airworthiness directive 05/94, dated August 1994, in 
order 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 replacement of 
center wing attachment rods having CASA part number (P/N) 35-22058-0003 
or 35-22067-0001 with new rods having CASA P/N 35-22067-0003. The 
actions would be required to be accomplished in accordance with the 
applicable service bulletins described previously.

Cost Impact

    The FAA estimates that 1 CASA Model CN-235 series airplane of U.S. 
registry would be affected by this proposed AD.
    It would take approximately 12 work hours per airplane to 
accomplish the proposed action, at an average labor rate of $60 per 
work hour. Required parts would cost approximately $1,485 per airplane. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators is estimated to be $2,205 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:

Construcciones Aeronauticas, S.A., CASA: Docket 96-NM-127-AD.

    Applicability: Model CN-235 series airplanes; as listed in CASA 
Service Bulletin SB-23-53-21M, Revision 1, dated November 21, 1994 
(military airplanes), and CASA Service Bulletin SB-235-53-21, 
Revision 3, dated November 30, 1994 (non-military 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 
otherwise modified, altered, or this AD is affected, the owner/
operator must request approval for an alternative method of 
compliance in accordance with paragraph (b) 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 fatigue from causing the center wing attachment rods 
to fail, which consequently could reduce the structural integrity of 
the wing-to-fuselage attachment, accomplish the following:
    (a) Prior to the accumulation of 16,000 total landings, replace 
center wing attachment rods having CASA part number (P/N) 35-22058-
0003 or 35-22067-0001 with new rods having CASA P/N 35-22067-0003, 
in accordance with CASA Service Bulletin SB-235-53-21M, Revision 1, 
dated November 21, 1994 (for military airplanes); or CASA Service 
Bulletin SB-235-53-21, Revision 3, dated November 30, 1994 (for non-
military airplanes); as applicable.
    (b) 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,

[[Page 3836]]

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.

    (c) Special flight permits may be issued in accordance with 
sections 21.197 and 121.199 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 January 15, 1997.
S. R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-1479 Filed 1-24-97; 8:45 am]
BILLING CODE 4910-13-U