[Federal Register Volume 61, Number 211 (Wednesday, October 30, 1996)]
[Proposed Rules]
[Pages 55939-55941]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-27757]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-CE-45-AD]
RIN 2120-AA64


Airworthiness Directives; Mitsubishi Heavy Industries, Ltd., MU-
2B Series Airplanes

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes to adopt a new airworthiness directive 
(AD) that would apply to certain Mitsubishi Heavy Industries, Ltd. 
(Mitsubishi) MU-2B series airplanes. The proposed action would require 
removing the vent check valve assembly from the bulkhead between the 
fuel tanks. The proposed action results from an incident where both 
engines on an affected airplane failed during the end of a flight. The 
incident is attributed to the fuel filler caps on the top of the wings 
not sealing correctly. The actions specified by the proposed AD are 
intended to prevent the inability of both engines to utilize the entire 
fuel supply because of the outboard fuel not transferring to the center 
tank, which could result in an uncommanded engine shutdown.

DATES: Comments must be received on or before January 3, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Central Region, Office of the Assistant Chief 
Counsel, Attention: Rules Docket No. 96-CE-45-AD, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106. Comments may be inspected at 
this location between 8 a.m. and 4 p.m., Monday through Friday, 
holidays excepted.
    Service information that applies to the proposed AD may be obtained 
from Mitsubishi Heavy Industries, Ltd., Nagoya Aerospace Systems, 10, 
Oyecho, Minato-Ku, Nagoya, Japan. This information also may be examined 
at the Rules Docket at the address above.

FOR FURTHER INFORMATION CONTACT: Mr. Eric M. Smith, Aerospace Engineer, 
FAA, Los Angeles Aircraft Certification Office, 3960 Paramount 
Boulevard., Lakewood, California 90712; telephone (310) 627-5260; 
facsimile (310) 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 should 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 that summarizes each FAA-public contact concerned 
with the substance of this

[[Page 55940]]

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 No. 96-CE-45-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, Central Region, Office of the Assistant Chief Counsel, 
Attention: Rules Docket No. 96-CE-45-AD, Room 1558, 601 E. 12th Street, 
Kansas City, Missouri 64106.

Discussion

    The FAA has received a report of an incident where both engines on 
a Mitsubishi MU-2B series airplane failed during the end of a flight. 
The airplane landed in a field short of the runway. Investigation of 
the accident revealed fuel leakage from the fuel filler caps. This is 
attributed to the fuel filler caps not sealing properly. This 
condition, if not detected and corrected, could result in outboard fuel 
not transferring to the center tank, which would make this fuel 
unavailable to both engines.

Explanation of the Applicable Service Information

    Mitsubishi MU-2 Service Bulletin (SB) No. 130A, dated July 19, 
1971, specifies procedures for removing the vent check valve assembly 
from the bulkhead between the fuel tanks. When the vent check valve 
assembly is removed in accordance with this service bulletin, fuel will 
transfer to the center tank regardless of the condition of the fuel 
filler cap seal.

The FAA's Determination

    After examining the circumstances and reviewing all available 
information related to the incidents described above, including the 
referenced service information, the FAA has determined that AD action 
should be taken to prevent the inability of both engines to utilize the 
entire fuel supply because of the outboard fuel not transferring to the 
center tank, which could result in an uncommanded engine shutdown.

Explanation of the Provisions of the Proposed AD

    Since an unsafe condition has been identified that is likely to 
exist or develop in other Mitsubishi MU-2B series airplanes of the same 
type design, the proposed AD would require removing the vent check 
valve assembly from the bulkhead between the fuel tanks. Accomplishment 
of the proposed action would be in accordance with Mitsubishi MU-2 SB 
No. 130A, dated July 19, 1971.

Compliance Time of the Proposed AD

    The compliance time for the proposed AD is presented in calendar 
time instead of hours time-in-service. The fuel filler cap may not seal 
properly regardless of whether the airplane is in operation. For this 
reason, the FAA has determined that a calendar time for compliance is 
the most desirable for the proposed AD.

Cost Impact

    The FAA estimates that 14 airplanes in the U.S. registry would be 
affected by the proposed AD, that it would take approximately 3 
workhours (average: 4 workhours for 7 airplanes and 2 workhours for 7 
airplanes) per airplane to accomplish the proposed action, and that the 
average labor rate is approximately $60 an hour. Based on these 
figures, the total cost impact of the proposed AD on U.S. operators is 
estimated to be $2,520.
    The above figure is based on the assumption that no owner/operator 
of the affected airplanes has accomplished the proposed vent check 
valve assembly removal. The FAA is aware that 7 of the affected 
airplanes are already in compliance with the proposed action. With this 
information in mind, the cost impact upon U.S. operators/owners would 
be reduced by $1,260 from $2,520 to $1,260.

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 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) 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 has been placed 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 USC 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by adding a new airworthiness directive 
(AD) to read as follows:

Mitsubishi Heavy Industries, Ltd.: Docket No. 96-CE-45-AD. 
Applicability: Models MU-2B, MU-2B-10, MU-2B-15, MU-2B-20, and MU-
2B-30 airplanes (serial numbers 004 through 035, 037, 038, 101 
through 230, 502 through 525, and 527 through 547), 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 within the next 60 calendar days 
after the effective date of this AD, unless already accomplished.

    To prevent the inability of both engines to utilize the entire 
fuel supply because of the outboard fuel not transferring to the 
center tank, which could result in an uncommanded engine shutdown, 
accomplish the following:
    (a) Remove the vent check valve assembly in accordance with the 
instructions in Mitsubishi MU-2 Service Bulletin No. 130A, dated 
July 19, 1971.
    (b) 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.

[[Page 55941]]

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an equivalent level of safety may be 
approved by the Manager, FAA, Los Angeles Aircraft Certification 
Office (ACO), 3960 Paramount Boulevard, Lakewood, California 90712. 
The request shall be forwarded through an appropriate FAA 
Maintenance Inspector, who may add comments and then send it to the 
Manager, Los Angeles ACO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this AD, if any, may be 
obtained from the Los Angeles ACO.

    (d) All persons affected by this directive may obtain copies of 
the document referred to herein upon request to Mitsubishi Heavy 
Industries, Ltd., Nagoya Aerospace Systems, 10, Oyecho, Minato-Ku, 
Nagoya, Japan; or may examine this document at the FAA, Central 
Region, Office of the Assistant Chief Counsel, Room 1558, 601 E. 
12th Street, Kansas City, Missouri 64106.

    Issued in Kansas City, Missouri, on October 22, 1996.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 96-27757 Filed 10-29-96; 8:45 am]
BILLING CODE 4910-13-P