[Federal Register Volume 62, Number 45 (Friday, March 7, 1997)]
[Proposed Rules]
[Pages 10488-10490]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-5574]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 96-NM-120-AD]
RIN 2120-AA64


Airworthiness Directives; Construcciones Aeronauticas, S.A. 
(CASA) Model C-212 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 all CASA Model C-212 series 
airplanes. This proposal would require an initial inspection of the 
restrictor pistons on the shock absorbers of the left and right main 
landing gear (MLG) to determine the number and condition of threaded 
screw pins that are installed; replacement of any discrepant pin; and 
repetitive inspections of certain pistons. Modification of certain 
pistons by the installation of two additional pins would terminate 
these inspections. This proposal is prompted by reports indicating that 
the threaded screw pin that holds the restrictor piston on the slide 
tube of the shock absorber has been found to have loosened on some 
airplanes. The actions specified by the proposed AD are intended to 
prevent the loss of hydraulic damping in the MLG, due to failure of the 
screw pins that hold the restrictor pistons on the slide tubes of the 
shock absorbers, and consequent structural damage to the airplane.

DATES: Comments must be received by April 16, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-120-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: Gregory 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 Docket Number 96-NM-120-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-120-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Direccion General de Aviacion (DGAC), which is the 
airworthiness authority for Spain, has notified the FAA that an unsafe 
condition may exist on all CASA Model C-212 series airplanes. The DGAC 
advises that it has

[[Page 10489]]

received reports indicating that threaded screw pins that hold the 
restrictor pistons on the slide tubes of the shock absorbers of the 
left and right main landing gear (MLG) have been found to have 
loosened.
    The piston is held on the slide tube by either one or three screw 
pins. On some pistons, two of the three screw pin holes have been 
drilled and sealed with epoxy; on other pistons, only one screw pin 
hole exists.
    Should the pin on a single-pin configuration become loose, the 
union between the piston and the slide tube may fail, causing the loss 
of hydraulic dampening in the MLG. This loss of hydraulic dampening, if 
not prevented, could result in structural damage to the airplane.

Explanation of Relevant Service Information

    CASA has issued Service Bulletin SB-212-32-38, dated June 16, 1994, 
which describes procedures for inspecting and installing the threaded 
screw pins that attach the restrictor pistons to the slide tubes of the 
shock absorbers of the left and right MLG. This service bulletin also 
describes procedures for modifying restrictor pistons on which only one 
threaded pin is installed. This modification entails the drilling of 
two new holes or the unsealing of two previously-drilled holes, and the 
installation of two more pins. Accomplishment of this modification will 
strengthen the union and resistance between the piston and the slide 
tube, and eliminate the need for repetitive inspections.
    The DGAC classified this service bulletin as mandatory and issued 
Spanish airworthiness directive 07/94, dated October 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 an initial 
inspection of the restrictor pistons on the shock absorbers of the left 
and right MLG to determine the number and condition of threaded screw 
pins that are installed; replacement of discrepant pins; and repetitive 
inspections of certain pistons. Pistons on which one pin is installed 
would be required to be modified by drilling two new holes or unsealing 
two-previously drilled holes, and installing two pins. This 
modification would terminate the requirement for repetitive 
inspections. The actions would be required to be accomplished in 
accordance with the service bulletin described previously.

Cost Impact

    The FAA estimates that 41 CASA Model C-212 series airplanes of U.S. 
registry would be affected by this proposed AD.
    It would take approximately 20 work hours per airplane to 
accomplish the proposed actions, and the average labor rate is $60 per 
work hour. Required parts would cost approximately $11 per airplane. 
Based on these figures, the cost impact of the proposed AD on U.S. 
operators is estimated to be $49,651, or $1,211 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-120-AD.

    Applicability: All Model C-212 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 
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 (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 the loss of hydraulic damping in the main landing 
gear, due to failure of the screw pins that hold the restrictor 
pistons on the slide tubes of the shock absorbers, and consequent 
structural damage to the airplane, accomplish the following:
    (a) Prior to the accumulation of 600 hours time-in-service after 
the effective date of this AD, conduct an inspection of each restrictor 
piston to detect the number and condition of installed threaded screw 
pins; in accordance with CASA Service Bulletin SB-212-32-38, dated June 
16, 1994. Prior to further

[[Page 10490]]

flight, replace any loose pin, in accordance with the service bulletin 
and accomplish the following, as applicable:
    (1) For any piston on which three threaded screw pins are 
installed: No further action is required by this AD for this piston.
    (2) For any piston on which one pin is installed and two holes are 
sealed with epoxy: Remove the epoxy, and install two additional 
threaded screw pins, in accordance with the service bulletin. 
Thereafter, no further action is required by this AD for this piston.
    (3) For any piston on which one pin is installed and no other holes 
exist:
    (i) Repeat the inspection required by paragraph (a) of this AD at 
intervals not to exceed 600 hours time-in-service until the 
modification required by paragraph (a)(3)(ii) of this AD is 
accomplished.
    (ii) Prior to the accumulation of 1,800 hours time-in-service after 
the effective date of this AD, or within 3 years after the effective 
date of this AD, whichever occurs later, modify this piston in 
accordance with the service bulletin. Accomplishment of this 
modification constitutes terminating action for the repetitive 
inspection requirements of paragraph (a)(3)(i) of this AD. Thereafter, 
no further action is required by this AD with regard to that piston.
    (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, 
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 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 28, 1997.
Darrell M. Pederson,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-5574 Filed 3-6- 97; 8:45 am]
BILLING CODE 4910-13-U