[Federal Register Volume 64, Number 168 (Tuesday, August 31, 1999)]
[Proposed Rules]
[Pages 47442-47446]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-22528]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-NM-300-AD]
RIN 2120-AA64


Airworthiness Directives; Mitsubishi Model YS-11 and YS-11A 
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 Mitsubishi Model YS-11 and YS-
11A series airplanes. This proposal would require repetitive removal of 
the spinner; repetitive detailed visual inspections of the propeller 
hub to detect fatigue cracking; and replacement of a propeller hub with 
a new propeller hub, if necessary. 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 propeller 
hub, which could cause the loss of the propeller.

DATES: Comments must be received by September 30, 1999.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-114,

[[Page 47443]]

Attention: Rules Docket No. 98-NM-300-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 Nihon Aeroplane Manufacturing, Toranomon Daiichi, 
Kotohire-Cho, Shiba, Minato-Ku, Tokyo, Japan. This information may be 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, Transport Airplane Directorate, 
Los Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California.

FOR FURTHER INFORMATION CONTACT: Jon Mowery, Aerospace Engineer, 
Airframe Branch, ANM-120L, FAA, Transport Airplane Directorate, Los 
Angeles Aircraft Certification Office, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (562) 627-5322; fax (562) 
627-5210.

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-300-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-300-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    The Japan Civil Aviation Bureau (JCAB), which is the airworthiness 
authority for Japan, notified the FAA that an unsafe condition may 
exist on all Mitsubishi YS-11 and YS-11A series airplanes. The JCAB 
advises that cracking has been found on propeller hubs. This cracking 
has been attributed to material fatigue. This condition, if not 
corrected, could result in the loss of the propeller.
    The JCAB has issued Japanese airworthiness directive TCD-4667-97, 
dated October 13, 1997, which describes procedures for repetitive 
removal of the spinner; repetitive detailed visual inspections to 
detect fatigue cracking of the propeller hub; and replacement of 
cracked propeller hubs with new propeller hubs, if necessary. The JCAB 
classified these actions as mandatory in order to assure the continued 
airworthiness of these airplanes in Japan.

FAA's Conclusions

    These airplane models are manufactured in Japan and are 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 JCAB has kept the FAA informed 
of the situation described above. The FAA has examined the findings of 
the JCAB, 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 Japanese airworthiness directive described 
previously.

Differences Between Proposed Rule and Foreign Airworthiness 
Directive

    The proposed AD would differ from the parallel Japanese 
airworthiness directive in that it would require accomplishment of the 
inspection within 25 flight hours or 30 days after the effective date 
of this AD, whichever occurs first. The parallel Japanese airworthiness 
directive requires accomplishment of the inspection prior to further 
flight, unless an inspection was performed within 25 flight hours 
before the effective date of the Japanese airworthiness directive. In 
developing an appropriate compliance time for this AD, the FAA 
considered not only the safety implications, but the Japanese 
airworthiness authority's requirements, the availability of required 
parts, and the practical aspect of accomplishing the inspection within 
an interval of time that parallels normal scheduled maintenance for 
affected operators. The FAA also considered the fact that the Japanese 
airworthiness directive (containing the procedures for accomplishing 
the required actions) has been available to all operators of Mitsubishi 
Model YS-11 and YS-11A series airplanes since October 1997. Therefore, 
U.S. operators have had ample time since then to consider initiating 
those actions, which this proposed AD ultimately mandates.

Cost Impact

    The FAA estimates that 25 airplanes of U.S. registry would be 
affected by this proposed AD, that it would take approximately 32 work 
hours per airplane to accomplish the proposed inspection, and that the 
average labor rate is $60 per work hour. Based on these figures, the 
cost impact of the proposed AD on U.S. operators is estimated to be 
$48,000, or $1,920 per airplane, per inspection cycle.
    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

[[Page 47444]]

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:

Mitsubish Heavy Industries, Ltd.: Docket 98-NM-300-AD.

    Applicability: All Model YS-11 and YS-11A 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 (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 detect and correct fatigue cracking of the propeller hub, 
which could cause the loss of the propeller, accomplish the 
following:

Inspection and Replacement

    (a) Within 25 flight hours or 30 days after the effective date 
of this AD, whichever occurs first, remove the spinner and perform a 
detailed visual inspection for cracking of the propeller hub in the 
crack area shown in Figure 1 of this AD.

    Note 2: For the purposes of this AD, a detailed visual 
inspection is defined as: ``An intensive visual examination of a 
specific structural area, system, installation, or assembly to 
detect damage, failure, or irregularity. Available lighting is 
normally supplemented with a direct source of good lighting at 
intensity deemed appropriate by the inspector. Inspection aids such 
as mirror, magnifying lenses, etc., may be used. Surface cleaning 
and elaborate access procedures may be required.''

    (1) If no crack is found, repeat the actions required by 
paragraph (a) of this AD thereafter at intervals not to exceed 25 
flight hours.
    (2) If any crack is detected, prior to further flight, replace 
the hub with a new hub. Repeat the actions required by paragraph (a) 
of this AD thereafter at intervals not to exceed 25 flight hours.

Alternative Methods of Compliance

    (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, Los Angeles Aircraft Certification 
Office (ACO), 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, Los Angeles ACO.

    Note 3: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

Special Flight Permits

    (c) Special flight permits may be issued for non-revenue bearing 
flights with essential crew only 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 4: The subject of this AD is addressed in Japanese 
airworthiness directive TCD-4667-97, dated October 13, 1997.

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    Issued in Renton, Washington, on August 24, 1999.
Vi L. Lipski,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-22528 Filed 8-30-99; 8:45 am]
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