[Federal Register Volume 64, Number 95 (Tuesday, May 18, 1999)]
[Rules and Regulations]
[Pages 26831-26833]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-12098]



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  Federal Register / Vol. 64, No. 95 / Tuesday, May 18, 1999 / Rules 
and Regulations  

[[Page 26831]]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-NM-92-AD; Amendment 39-11169; AD 99-10-16]
RIN 2120-AA64


Airworthiness Directives; Mitsubishi Model YS-11 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 series airplanes, that 
requires repetitive inspections to detect fatigue cracking in the 
manhole doublers of the lower wing panels; and repair, if necessary. 
This amendment also requires eventual modification of screw holes in 
the manhole doublers of the lower wing panels, which constitutes 
terminating action for the repetitive inspections required by this AD. 
This amendment is prompted by the issuance of mandatory continuing 
airworthiness information by a foreign civil airworthiness authority. 
The actions specified by this AD are intended to prevent fatigue 
cracking in the manhole doublers of the lower wing panels, which could 
result in failure of the wing structure.

DATES: Effective June 22, 1999.
    The incorporation by reference of certain publications listed in 
the regulations is approved by the Director of the Federal Register as 
of June 22, 1999.

ADDRESSES: The service information referenced in this AD may be 
obtained from Mitsubishi Heavy Industries, Ltd., 10 Oye-cho, Minato-ku, 
Nagoya 455, 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, 
Transport Airplane Directorate, Los Angeles Aircraft Certification 
Office, 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: 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: 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 series 
airplanes was published in the Federal Register on July 9, 1998 (63 FR 
37080). That action proposed to require repetitive inspections to 
detect fatigue cracking in the manhole doublers of the lower wing 
panels; and repair, if necessary. That action also proposed to require 
eventual modification of screw holes in the manhole doublers of the 
lower wing panels.

Comments

    Interested persons have been afforded an opportunity to participate 
in the making of this amendment. Due consideration has been given to 
the comments received.

Request To Accept Modification as Terminating Action

    Two commenters request that modification of the screw holes in the 
manhole doublers of the lower wing panels, as described in NAMC Service 
Bulletin 57-77, Revision 2, dated September 14, 1994, and specified in 
paragraph (b) of the proposed AD, be considered terminating action for 
the repetitive inspections described in paragraph (a) of the proposed 
rule. ``NOTE 2'' of the proposed AD states, ``Accomplishment of the 
modification specified in paragraph (b) does not constitute terminating 
action for the repetitive inspections of paragraph (a).'' The 
commenters state that repetitive inspections of the screw holes in the 
manhole doublers of the lower wing panels are no longer necessary after 
accomplishment of the modification, though inspection of the rivet 
holes in the skin around the manhole, as specified in SID Item 57-00-
03, is still necessary.
    The FAA concurs with the commenters' request to accept the 
modification as terminating action for the repetitive inspections. The 
FAA has reviewed Mitsubishi NAMC Service Bulletin 57-77, Revision 2, 
and SID Item 57-00-03, and finds that repetitive inspections of the 
screw holes in the manhole doublers of the lower wing panels are no 
longer necessary after accomplishment of the modification specified in 
the service bulletin. Therefore, paragraph (b) of this final rule has 
been revised to eliminate reference to repair of any cracking detected 
during repetitive inspections performed after accomplishment of the 
modification, and to state that accomplishment of such modification 
terminates the repetitive inspection requirement of this AD. In 
addition, a reference to the modification as terminating action for the 
repetitive inspections has been added to the ``Summary'' section of 
this final rule. Also, ``NOTE 2'' of this final rule has been revised 
to state, ``Mitsubishi NAMC Supplemental Inspection Document (SID) Item 
57-00-03 describes inspections of certain rivet holes in the skin 
around the manhole. Accomplishment of the modification specified in 
paragraph (b) of this AD does not eliminate the need for the 
inspections specified in that SID item.''

Request To Revise Address for Obtaining Service Information

    One commenter requests that the proposed rule be revised to 
reference the correct address from which service information may be 
obtained. The commenter points out that Mitsubishi Heavy Industries, 
not Nihon Aeroplane Manufacturing Company (NAMC) (which was referenced 
as the appropriate source for the service information specified in the 
proposal), provides technical publications for owners and operators of 
Mitsubishi Model YS-11 series airplanes. The FAA concurs with the 
commenter's request and has revised this final rule to reference the 
correct address.

[[Page 26832]]

Request To Revise Information From NAMC Structural Inspection 
Document

    Two commenters request that the proposed AD be revised to more 
accurately reflect the information in NAMC Supplemental Inspection 
Document (SID) Item 57-00-03. The commenters point out that the 
following statement in the preamble of the proposed AD under the 
heading ``Differences Between Proposed Rule, Service Information, and 
Japanese Airworthiness Directive'' is incorrect: ``Following 
accomplishment of the modification described in the service bulletin, 
the SID item specifies that the repetitive interval is reduced to 6,000 
flight cycles.'' One of the commenters attributes the misstatement in 
the proposed AD to a misunderstanding of a transmittal letter that 
accompanied the SID. That commenter states that the change in 
repetitive inspection interval referenced by the transmittal letter is 
for a different inspection item within the SID (Inspection Item 57-00-
06), and the repetitive interval for the inspection in SID Item 57-00-
03 remains at 8,000 flight cycles.
    The FAA acknowledges that the proposed AD could have more 
accurately reflected the information in SID Item 57-00-03. However, the 
proposed AD is unaffected by the statement in the preamble. Because the 
section of the preamble that discusses the reduction of the repetitive 
interval is not repeated in the final rule, no change to the final rule 
is necessary in this regard.

Request To Revise Information From Japanese Airworthiness Directive

    One commenter requests that the proposed rule be revised to reflect 
the correct compliance date for the modification as specified in 
Japanese Airworthiness Directive TCD-3795-2-96, dated December 13, 
1996. Under the heading ``Differences Between Proposed Rule, Service 
Information, and Japanese Airworthiness Directive,'' the proposed rule 
states, `` * * * the Japanese airworthiness directive specifies that 
modification of the screw holes in the manhole doublers of the lower 
wing panels be accomplished prior to the accumulation of 60,000 total 
flight cycles, or before December 13, 2000 (four years after the 
effective date of the Japanese airworthiness directive), whichever 
occurs later.'' The commenter states that, due to a mistranslation in 
the English version of the AD, the date for required compliance is 
incorrect. The commenter goes on to state that the correct compliance 
date should be February 7, 1997, which is four years after the 
effective date of the original Japanese airworthiness directive (TCD-
3795-93, dated February 7, 1993). The FAA acknowledges that a 
mistranslation of the Japanese airworthiness directive occurred. 
However, the proposed AD is unaffected by the statement in the 
preamble. Because the subject section of the proposed rule is not 
restated in the final rule, no change to the final rule is necessary in 
this regard.

Request To Increase Repetitive Inspection Interval

    One commenter requests that the repetitive inspection interval be 
increased from 6,000 flight cycles, as specified in paragraph (a) of 
the proposed AD, to 8,000 flight cycles. As described previously, the 
commenter points out that SID Item 57-00-03 recommends a repetitive 
inspection interval of 8,000 flight cycles.
    The FAA does not concur with the commenter's request to increase 
the repetitive inspection interval from 6,000 to 8,000 flight cycles. 
In developing an appropriate compliance time for this AD, the FAA 
considered not only the repetitive inspection interval specified in SID 
Item 57-00-03, but also the degree of urgency associated with 
addressing the subject unsafe condition (fatigue cracking in the 
manhole doublers of the lower wing panels, which could result in 
failure of the wing structure). In light of these factors, as well as 
engineering judgement and experience, the FAA has determined that, due 
to the safety implications and consequences associated with the 
identified unsafe condition, a repetitive inspection interval that is 
more conservative than the 8,000-flight-cycle interval recommended by 
SID Item 57-00-03 is warranted. The FAA finds that an interval of 6,000 
flight cycles will better ensure that any cracking of the manhole 
doublers of the lower wing panels is detected and corrected in a timely 
manner. No change to the final rule is necessary in this regard.

Conclusion

    After careful review of the available data, including the comments 
noted above, the FAA has determined that air safety and the public 
interest require the adoption of the rule with the changes described 
previously. The FAA has determined that these changes will neither 
increase the economic burden on any operator nor increase the scope of 
the AD.

Cost Impact

    The FAA estimates that 25 airplanes of U.S. registry will be 
affected by this AD.
    It will take approximately 30 work hours per airplane to accomplish 
the required inspection, at an average labor rate of $60 per work hour. 
Based on these figures, the cost impact of the inspection required by 
this AD on U.S. operators is estimated to be $45,000, or $1,800 per 
airplane, per inspection cycle.
    It will take approximately 40 work hours per airplane to accomplish 
the required modification, at an average labor rate of $60 per work 
hour. Based on these figures, the cost impact of the modification 
required by this AD on U.S. operators is estimated to be $60,000, or 
$2,400 per airplane.
    The cost impact figures discussed above are 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

[[Page 26833]]

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:

99-10-16  Mitsubishi Heavy Industries, Ltd.: Amendment 39-11169. 
Docket 97-NM-92-AD.

    Applicability: All Model YS-11 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 (c) 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 cracking in the manhole doublers of the lower 
wing panels, which could result in failure of the wing structure, 
accomplish the following:

Initial and Repetitive Inspections

    (a) Perform a visual inspection to detect cracking in the 
manhole doublers and around the screw holes of the lower wing 
panels, in accordance with Mitsubishi Nihon Aeroplane Manufacturing 
Company (NAMC) Service Bulletin 57-77, Revision 2, dated September 
14, 1994, at the time specified in either paragraph (a)(1) or (a)(2) 
of this AD, as applicable. Repeat the inspection thereafter at 
intervals not to exceed 6,000 flight cycles.
    (1) For airplanes that have accumulated fewer than 45,000 total 
flight cycles as of the effective date of this AD: Prior to the 
accumulation of 45,000 total flight cycles, or within 1 year after 
the effective date of this AD, whichever occurs later, perform the 
initial inspection.
    (2) For airplanes that have accumulated 45,000 or more total 
flight cycles as of the effective date of this AD: Within 2,000 
flight cycles or 1 year after the effective date of this AD, 
whichever occurs first, perform the initial inspection.

Modification

    (b) Modify the screw holes in the manhole doublers of the lower 
wing panels, in accordance with Mitsubishi NAMC Service Bulletin 57-
77, Revision 2, dated September 14, 1994, at the applicable time 
specified in either paragraph (b)(1) or (b)(2) of this AD. 
Accomplishment of such modification constitutes terminating action 
for the repetitive inspections required by paragraph (a) of this AD.

    Note 2: Mitsubishi NAMC Supplemental Inspection Document (SID) 
Item 57-00-03 describes inspections of certain rivet holes in the 
skin around the manhole. Accomplishment of the modification 
specified in paragraph (b) of this AD does not eliminate the need 
for the inspections specified in that SID item.

    (1) If no cracking is found, prior to the accumulation of 60,000 
total flight cycles, or within 1 year after the effective date of 
this AD, whichever occurs later, accomplish the modification in 
accordance with the service bulletin.
    (2) If any cracking is found, prior to further flight, repair 
the cracking and accomplish the modification, in accordance with the 
service bulletin.

Alternative Methods of Compliance

    (c) 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

    (d) 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.

Incorporation by Reference

    (e) The inspection and modification shall be done in accordance 
with Mitsubishi Nihon Aeroplane Manufacturing Company (NAMC) Service 
Bulletin 57-77, Revision 2, dated September 14, 1994, which contains 
the following list of effective pages:

------------------------------------------------------------------------
                         Revision level shown
      Page number               on page            Date shown on page
------------------------------------------------------------------------
 1-3..................  2.....................  September 14, 1994.
4-16..................  1.....................  November 4, 1993.
17, 18................  Original..............  January 8, 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 Mitsubishi Heavy Industries, Ltd., 
10 Oye-cho, Minato-ku, Nagoya 455, Japan. Copies may be inspected 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; or at the Office of the Federal Register, 800 
North Capitol Street, NW., suite 700, Washington, DC.

    Note 4: The subject of this AD is addressed in Japanese 
airworthiness directive TCD-3795-2-96, dated December 13, 1996.
    (f) This amendment becomes effective on June 22, 1999.

    Issued in Renton, Washington, on May 7, 1999.
D. L. Riggin,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 99-12098 Filed 5-17-99; 8:45 am]
BILLING CODE 4910-13-U