[Federal Register Volume 60, Number 130 (Friday, July 7, 1995)]
[Rules and Regulations]
[Pages 35328-35330]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-15996]



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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 94-NM-167-AD; Amendment 39-9297; AD 95-14-05]


Airworthiness Directives; Mitsubishi Model YS-11 and -11A 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 Mitsubishi Model YS-11 and -11A series airplanes, 
that requires the implementation of a corrosion prevention and control 
program. This amendment is prompted by incidents involving corrosion 
and fatigue cracking in transport category airplanes that are 
approaching or have exceeded their economic design goal; these 
incidents have jeopardized the airworthiness of the affected airplanes. 
The actions specified by this AD are intended to prevent degradation of 
the structural capabilities of the affected airplanes due to problems 
associated with corrosion.

DATES: Effective August 7, 1995.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of August 7, 1995.

ADDRESSES: The service information referenced in this AD may be 
obtained from Nihon Aeroplane Manufacturing, Toranomon Daiichi, 
Kotohire-Cho, Shiba, Minato-Ku, Tokyo, Japan. 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 FAA, Los Angeles Aircraft Certification Office, 
Transport Airplane Directorate, 3960 Paramount Boulevard, Lakewood, 
California; or at the Office of the Federal Register, 800 North Capitol 
Street NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT: William Roberts, Aerospace Engineer, 
Airframe Branch, ANM-120L, Los Angeles Aircraft Certification Office, 
FAA, Transport Airplane Directorate, 3960 Paramount Boulevard, 
Lakewood, California 90712-4137; telephone (310) 627-5228; fax (310) 
627-5210.

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 Mitsubishi Model YS-11 and -
11A series airplanes was published in the Federal Register on April 19, 
1995 (60 FR 19545). That action proposed to require the implementation 
of a corrosion prevention and control program.
    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. 
The FAA has determined that air safety and the public interest require 
the adoption of the rule as proposed.
    The FAA estimates that 39 airplanes of U.S. registry will be 
affected by this AD, that it will take approximately 8 work hours per 
basic task to accomplish the 30 basic tasks called out in MHI 
Publication No. YS-MR-301, ``YS-11 Corrosion Control Program,'' dated 
November 1, 1993; this represents a total average of 240 work hours 
(this figure includes not only inspection time, but access and closure 
time as well). The average labor rate is $60 per work hour. Based on 
these figures, the total cost impact of the AD on U.S. operators for 
the 4-year average inspection cycle is estimated to be $561,600, or 
$14,400 per airplane.
    The total 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.
    The FAA recognizes that the obligation to maintain aircraft in an 
airworthy condition is vital, but sometimes expensive. Because AD's 
require specific actions to address specific unsafe conditions, they 
appear to impose costs that would not otherwise be borne by operators. 
However, because of the general obligation of operators to maintain 
aircraft in an airworthy condition, this appearance is deceptive. 
Attributing those costs solely to the issuance of this AD is 
unrealistic because, in the interest of maintaining safe aircraft, 
prudent operators would accomplish the required actions even if they 
were not required to do so by the AD.
    A full cost-benefit analysis has not been accomplished for this AD. 
As a matter of law, in order to be airworthy, an aircraft must conform 
to its type design and be in a condition for safe operation. The type 
design is approved only after the FAA makes a determination that it 
complies with all applicable airworthiness requirements. In adopting 
and maintaining those requirements, the FAA has already made the 
determination that they establish a level of safety that is cost-
beneficial. When the FAA, as in this AD, makes a finding of an unsafe 
condition, this means that the original cost-beneficial level of safety 
is no longer being achieved and that the required actions are necessary 
to restore that level of safety. Because this level of safety has 
already been determined to be cost-beneficial, a full cost-benefit 
analysis for this AD would be redundant and unnecessary.
    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: 

[[Page 35329]]


PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. App. 1354(a), 1421 and 1423; 49 U.S.C. 
106(g); and 14 CFR 11.89.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding the following new 
airworthiness directive:

95-14-05 Mitsubishi Heavy Industries, Ltd: Amendment 39-9297. Docket 
94-NM-167-AD.

    Applicability: All Model YS-11 and -11A 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 use the authority 
provided in paragraph (h) of this AD to request approval from the 
FAA. This approval may address either no action, if the current 
configuration eliminates the unsafe condition; or different actions 
necessary to address the unsafe condition described in this AD. Such 
a request should include an assessment of the effect of the changed 
configuration on the unsafe condition addressed by this AD. In no 
case does the presence of any modification, alteration, or repair 
remove any airplane from the applicability of this AD.
    Compliance: Required as indicated, unless accomplished 
previously.

    Note 2: This AD references MHI Publication No. YS-MR-301, ``YS-
11 Corrosion Control Program,'' dated November 1, 1993 (hereafter 
referred to as ``the Document''), for basic tasks, definitions of 
corrosion levels, compliance times, and reporting requirements. In 
addition, this AD specifies inspection and reporting requirements 
beyond those included in the Document. Where there are differences 
between the AD and the Document, the AD prevails.
    Note 3: As used throughout this AD, the term ``the FAA'' is 
defined differently for different operators, as follows: For those 
operators complying with paragraph (a) of this AD, ``the FAA'' is 
defined as ``the Manager of the Los Angeles Aircraft Certification 
Office (ACO).'' For those operators operating under Federal Aviation 
Regulation (FAR) Part 121 or 129, and complying with paragraph (b) 
of this AD, ``the FAA'' is defined as ``the cognizant Principal 
Maintenance Inspector (PMI).'' For those operators operating under 
FAR Part 91 or 125, and complying with paragraph (b) of this AD, 
``the FAA'' is defined as ``the cognizant Maintenance Inspector at 
the appropriate FAA Flight Standards office.''

    To preclude degradation of the structural capabilities of the 
airplane due to the problems associated with corrosion, accomplish 
the following:
    (a) Except as provided in paragraph (b) of this AD, within a 
date two years after the effective date of this AD, complete each of 
the basic tasks specified in Section 4.3 of the Document in 
accordance with the procedures specified in the Document and the 
schedule specified in Figure 5 of the Document. Thereafter, repeat 
each basic task at a time interval not to exceed the repeat interval 
specified in Section 4 of the Document for that task.

    Note 4: A ``basic task,'' as defined in Section 4 of the 
Document, includes inspections; procedures for a corrective action, 
including repairs, under identified circumstances; application of 
sealants or corrosion inhibitors; and other follow-on actions.
    Note 5: Basic tasks completed in accordance with the Document 
before the effective date of this AD may be credited for compliance 
with the initial basic task requirements of this paragraph.
    Note 6: Where non-destructive inspection (NDI) methods are 
employed, in accordance with Section 4 of the Document, the 
standards and procedures used must be acceptable to the 
Administrator in accordance with FAR Section 43.13.

    (b) As an alternative to the requirements of paragraph (a) of 
this AD: Within one year after the effective date of this AD, revise 
the FAA-approved maintenance/inspection program to include the 
corrosion control program specified in the Document; or to include 
an equivalent program that is approved by the FAA.
    (1) Any operator complying with paragraph (b) of this AD may use 
an alternative recordkeeping method to that otherwise required by 
FAR Section 91.417 or Section 121.380 for the actions required by 
this AD, provided it is approved by the FAA and is included in a 
revision to the FAA-approved maintenance/inspection program.
    (2) Subsequent to the accomplishment of the initial basic task, 
any extensions of repeat intervals specified in the Document must be 
approved by the FAA.
    (c) To accommodate unanticipated scheduling requirements, it is 
acceptable for a repeat interval to be increased by up to 10%, but 
not to exceed 6 months. The FAA must be informed, in writing, of any 
such extension within 30 days after such adjustment of the schedule.
    (d) (1) If, as a result of any inspection conducted in 
accordance with paragraphs (a) or (b) of this AD, Level 3 corrosion 
is determined to exist in any airplane area, accomplish either 
paragraph (d)(1)(i) or (d)(1)(ii) within 7 days after such 
determination:
    (i) Submit a report of that determination to the FAA and 
complete the basic task in the affected aircraft zones on all Model 
YS-11/ -11A series airplanes in the operator's fleet; or
    (ii) Submit to the FAA for approval one of the following:
    (A) A proposed schedule for performing the basic tasks in the 
affected aircraft zones on the remaining Model YS-11/ -11A series 
airplanes in the operator's fleet, which is adequate to ensure that 
any other Level 3 corrosion is detected in a timely manner, along 
with substantiating data for that schedule; or
    (B) Data substantiating that the Level 3 corrosion found is an 
isolated occurrence.

    Note 7: Notwithstanding the provisions of Section 1.3 of the 
Document, which would permit corrosion that otherwise meets the 
definition of Level 3 corrosion (i.e., which is determined to be a 
potentially urgent airworthiness concern requiring expeditious 
action) to be treated as Level 1 if the operator finds that it ``can 
be attributed to an event not typical of the operator's usage of 
other airplanes in the same fleet,'' this paragraph requires that 
data substantiating any such finding be submitted to the FAA for 
approval.

    (2) The FAA may impose schedules other than those proposed, upon 
finding that such changes are necessary to ensure that any other 
Level 3 corrosion is detected in a timely manner.
    (3) Within the time schedule approved under paragraph (d)(1) or 
(d)(2) of this AD, accomplish the basic tasks in the affected 
aircraft zones of the remaining Model YS-11/-11A series airplanes in 
the operator's fleet.
    (e) If, as a result of any inspection after the initial 
inspection conducted in accordance with paragraph (a) or (b) of this 
AD, it is determined that corrosion findings exceed Level 1 in any 
area, within 60 days after such determination, implement a means, 
approved by the FAA, to reduce future findings of corrosion in that 
area to Level 1 or better.
    (f) Before any operator places into service any airplane subject 
to the requirements of this AD, a schedule for the accomplishment of 
basic tasks required by this AD must be established in accordance 
with paragraph (f)(1) or (f)(2) of this AD, as applicable:
    (1) For airplanes previously maintained in accordance with this 
AD, the first basic task in each aircraft zone to be performed by 
the new operator must be accomplished in accordance with the 
previous operator's schedule or with the new operator's schedule, 
whichever would result in the earlier accomplishment date for that 
task. After each basic task has been performed once, each subsequent 
task must be performed in accordance with the new operator's 
schedule.
    (2) For airplanes that have not been previously maintained in 
accordance with this AD, the first basic task for each aircraft zone 
to be performed by the new operator must be accomplished prior to 
further flight or in accordance with a schedule approved by the FAA.
    (g) Reports of Level 2 and Level 3 corrosion must be submitted 
at least every three months to Mitsubishi Heavy Industries, Ltd., in 
accordance with Section 3 of the Document.

    Note 8: Reporting of Level 2 and Level 3 corrosion found as a 
result of any opportunity inspections is highly desirable.

    (h) 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 

[[Page 35330]]
an appropriate FAA Principal Maintenance Inspector, who may add 
comments and then send it to the Manager, Los Angeles ACO.

    Note 9: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (i) 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.
    (j) Reports of inspection results required by this AD have been 
approved by the Office of Management and Budget (OMB) under the 
provisions of the Paperwork Reduction Act of 1980 (44 U.S.C. 3501 et 
seq.) and have been assigned OMB Control Number 2120-0056.
    (k) The actions shall be done in accordance with MHI Publication 
No. YS-MR-301, ``YS-11 Corrosion Control Program,'' dated November 
1, 1993. 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 Nihon Aeroplane 
Manufacturing, Toranomon Daiichi, Kotohire-Cho, Shiba, Minato-Ku, 
Tokyo, Japan. Copies may be inspected at the FAA, Transport Airplane 
Directorate, 1601 Lind Avenue SW., Renton, Washington; or at the 
FAA, Los Angeles Aircraft Certification Office, Transport Airplane 
Directorate, 3960 Paramount Boulevard, Lakewood, California; or at 
the Office of the Federal Register, 800 North Capitol Street NW., 
suite 700, Washington, DC.
    (l) This amendment becomes effective on August 7, 1995.

    Issued in Renton, Washington, on June 23, 1995.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 95-15996 Filed 7-6-95; 8:45 am]
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