[Federal Register Volume 62, Number 18 (Tuesday, January 28, 1997)]
[Rules and Regulations]
[Pages 3994-3996]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-1480]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-76-AD; Amendment 39-9902; AD 97-02-17]
RIN 2120-AA64


Airworthiness Directives; Construcciones Aeronauticas, S.A. 
(CASA) Model CN-235 Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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SUMMARY: This amendment adopts a new airworthiness directive (AD), 
applicable to all CASA Model CN-235 series airplanes, that requires 
repetitive eddy current inspections to detect fatigue cracks in the 
nose landing gear (NLG) turning tube, and replacement of cracked tubes. 
This amendment is prompted by a report of the failure of an NLG turning 
tube during landing roll; the failure was attributed to fatigue 
cracking in the turning tube. The actions specified by this AD are 
intended to ensure that fatigue cracking in the NLG turning tube is 
detected and corrected before it could cause the failure of the tube 
and, consequently, degrade the structural integrity of the NLG.

DATES: Effective March 4, 1997.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of March 4, 1997.

ADDRESSES: The service information referenced in this AD may be 
obtained from Construcciones Aeronauticas, S.A., Getafe, Madrid, Spain. 
This information may be examined at the Federal Aviation Administration 
(FAA), Transport Airplane Directorate, Rules Docket, 1601 Lind Avenue, 
SW., Renton, Washington; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

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: A proposal to amend part 39 of the Federal 
Aviation Regulations (14 CFR part 39) to include an airworthiness 
directive (AD) that is applicable to all CASA Model CN-235 series 
airplanes was published in the Federal Register on October 23, 1996 (61 
FR 54958). That action proposed to require repetitive eddy current 
inspections to detect fatigue cracking in the nose landing gear (NLG)

[[Page 3995]]

turning tube. If any cracking is detected, the turning tube would be 
required to be replaced with a new unit prior to further flight.
    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. No comments were submitted in response 
to the proposal or the FAA's determination of the cost to the public.

Conclusion

    The FAA has determined that air safety and the public interest 
require the adoption of the rule as proposed.

Interim Action

    This is considered interim action until final action is identified, 
at which time the FAA may consider further rulemaking.

Cost Impact

    The FAA estimates that 1 CASA Model CN-235 series airplane of U.S. 
registry will be affected by this AD, that it will take approximately 8 
work hours per airplane to accomplish the required actions, and that 
the average labor rate is $60 per work hour. Required parts will be 
provided by the manufacturer at no cost to operators. Based on these 
figures, the cost impact of the AD on U.S. operators is estimated to be 
$480.
    The cost impact figure discussed above is based on assumptions that 
no operator has yet accomplished any of the 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 adopted herein will 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 final 
rule does not have sufficient federalism implications to warrant the 
preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this action (1) is 
not a ``significant regulatory action'' under Executive Order 12866; 
(2) is not a ``significant rule'' under DOT Regulatory Policies and 
Procedures (44 FR 11034, February 26, 1979); and (3) 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 final evaluation has been prepared for this action 
and it is contained in the Rules Docket. A copy of it may be obtained 
from the Rules Docket at the location provided under the caption 
ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Incorporation by 
reference, Safety.

Adoption of the Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration amends 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:

97-02-17 CASA: Amendment 39-9902. Docket 96-NM-76-AD.

    Applicability: All Model CN-235 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 (d) 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 structural degradation of the nose landing gear (NLG) 
due to failure of the NLG turning tube, accomplish the following:
    (a) At the applicable time specified in either paragraph (a)(1) 
or (a)(2) of this AD, conduct a high frequency eddy current (HFEC) 
inspection to detect fatigue cracking in the NLG turning tube, in 
accordance with the procedures specified in Annex 1 and Annex 2 of 
CASA Maintenance Instructions COM 235-092, Revision 02, dated May 5, 
1995.
    (1) For Model CN-235 airplanes [Basic model; Maximum Takeoff 
Weight (MTOW) = 31,746 lbs. (14,400 kgs.)]: Conduct the inspection 
prior to or upon the accumulation of 6,000 landings on the NLG 
turning tube, or within 50 landings after the effective date of this 
AD, whichever occurs later.
    (2) For Model CN-235-100 series airplanes [MTOW = 33,290 lbs. 
(15,100 kgs.)] and Model CN-235-200 series airplanes [MTOW = 34,833 
lbs. (15,800 kgs)]: Conduct the inspection prior to or upon the 
accumulation of 4,800 landings on the NLG turning tube, or within 50 
landings after the effective date of this AD, whichever occurs 
later.
    (b) If no cracking is detected during the inspection required by 
paragraph (a) of this AD, repeat the inspection thereafter at 
intervals not to exceed 200 landings.
    (c) If any cracking is detected during any inspection required 
by paragraph (a) or (b) of this AD, prior to further flight, replace 
the NLG turning tube with a new unit in accordance with CASA 
Maintenance Instructions COM 235-092, Revision 02, dated May 5, 
1995. After replacement, repeat the HFEC inspection prior to or upon 
the accumulation of 6,000 landings on the new NLG turning tube 
installed on Model CN-325 airplanes (basic model); or prior to or 
upon the accumulation of 4,800 landings on the new NLG turning tube 
installed on Model CN-325-100 and -200 series airplanes. Thereafter, 
repeat the inspection at intervals not to exceed 200 landings.
    (d) 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. 
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.

    (e) 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.
    (f) The inspections and relacement shall be done in accordance 
with CASA Maintenance Instructions COM 235-092, Revision 02, dated 
May 5, 1995, which contains the specified list of effective pages:

------------------------------------------------------------------------
                                    Revision level                      
           Page number               shown on page    Date shown on page
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1/2, 2/2........................  02................  May 5, 1995.      
Annex 1: 1-6....................  None..............  None.             
Annex 2: 1-3....................  None..............  None.             
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    This incorporation by reference was approved by the Director of 
the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR 
part 51. Copies may be obtained from Construcciones Aeronauticas, 
S.A., Getafe, Madrid, Spain. Copies may be inspected at the FAA, 
Transport Airplane Directorate, 1601 Lind Avenue, SW., Renton, 
Washington; or at the Office of the Federal Register, 800 North 
Capitol Street, NW., suite 700, Washington, DC.
    (g) This amendment becomes effective on March 4, 1997.


[[Page 3996]]


    Issued in Renton, Washington, on January 15, 1997.
S.R. Miller,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-1480 Filed 1-27-97; 8:45 am]
BILLING CODE 4910-13-U