[Federal Register Volume 59, Number 102 (Friday, May 27, 1994)]
[Unknown Section]
[Page 0]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 94-12717]
[[Page Unknown]]
[Federal Register: May 27, 1994]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 39
[Docket No. 94-CE-09-AD; Amendment 39-8920; AD 94-11-04]
Airworthiness Directives: Mitsubishi Heavy Industries MU-2B
Series Airplanes
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: This amendment adopts a new airworthiness directive (AD) that
applies to certain Mitsubishi Heavy Industries MU-2B series airplanes.
This action requires adjusting the engine underspeed governor minimum
stop (ground idle) and the airframe condition control linkage,
modifying the tachometer indicator markings, fabricating and installing
a placard that specifies a minimum idle speed, and incorporating
Airplane Flight Manual (AFM) revisions. An accident of one of the
affected airplanes where the propeller hub assembly failed and the
propeller separated from the airplane prompted this action. Accident
investigation analysis indicates a reduction in fatigue strength of the
propeller hub because of high vibration frequencies during ground idle
speed. The actions specified by this AD are intended to prevent
propeller hub arm assembly failure because of high vibration
frequencies during ground idle speed and possible separation of the
propeller from the airplane, which could result in loss of control of
the airplane.
DATES: Effective June 10, 1994.
The incorporation by reference of certain publications listed in
the regulations is approved by the Director of the Federal Register as
of June 10, 1994.
Comments for inclusion in the Rules Docket must be received on or
before July 29, 1994.
ADDRESSES: Submit comments in triplicate to the Federal Aviation
Administration (FAA), Central Region, Office of the Assistant Chief
Counsel, Attention: Rules Docket 94-CE-09-AD, room 1558, 601 E. 12th
Street, Kansas City, Missouri 64106.
Information that relates to this AD may be obtained from the Beech
Aircraft Corporation, P.O. Box 85, Wichita, Kansas 67201-0085; or
Mitsubishi Heavy Industries, Ltd., 5-1 Marunouchi 2 Chome, Chiyoda-ku,
Tokyo Japan. This information may also be examined at the Federal
Aviation Administration (FAA), Central Region, Office of the Assistant
Chief Counsel, Attention: Rules Docket 94-CE-09-AD, room 1558, 601 E.
12th Street, Kansas City, Missouri 64106; or at the Office of the
Federal Register, 800 North Capitol Street NW., suite 700, Washington,
DC.
FOR FURTHER INFORMATION CONTACT: Mr. Charles D. Riddle, Aerospace
Engineer, FAA, Wichita Aircraft Certification Office, 1801 Airport
Road, room 100, Wichita, Kansas 67209; telephone (316) 946-4144;
facsimile (316) 946-4407.
SUPPLEMENTARY INFORMATION: A recent accident of a Mitsubishi Model MU-
2B-60 airplane where the propeller hub assembly failed and the
propeller separated from the airplane prompted the FAA and the National
Transportation Safety Board (NTSB) to investigate the vibration
frequency of these airplanes during ground idle operation. Accident
investigation analysis indicates a reduction in fatigue strength of the
propeller hub because of high vibration frequencies during ground idle
speed. These high vibration frequencies, if not corrected, eventually
will result in the above-referenced propeller hub assembly failure and
separation of the propeller from the airplane.
After examining the circumstances and reviewing all available
information related to the incidents described above, the FAA has
determined that (1) certain precautions (in addition to those taken by
previous AD actions and during initial certification of the airplane)
should be taken to minimize these high vibration frequencies during
ground idle speed; and (2) AD action should be taken to prevent the
above-referenced conditions.
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, this AD requires adjusting the engine underspeed governor
minimum stop (ground idle) and the airframe condition control linkage,
modifying the tachometer indicator markings, fabricating and installing
a placard that specifies a minimum idle speed, and incorporating
Airplane Flight Manual (AFM) revisions. The ground idle modification is
required to be accomplished in accordance with the Allied Signal
Garrett Maintenance Manual (Report No. 72-00-95 for TPE331-10-501M or
Report No. 72-00-27 for TPE331-501M or -511M), chapter 72-00-00,
General-Adjustment/Test; and chapter 76-10- 01, Control Linkage
Assembly, Maintenance Practices. The airframe control linkage
modification is required to be accomplished in accordance with chapter
6, Sec. 9.2, of the applicable Mitsubishi MU-2 maintenance manual. The
revisions to the applicable Airplane Flight Manual are as follows:
------------------------------------------------------------------------
Date and revision
Model Effective pages level
------------------------------------------------------------------------
MU-2B-26A.............. 1, 2, Revision log 2, 1- FAA approved 1-12-77
5, 5-10, 5-13, and 5- reissued 03-25-86
23. revision 4.
MU-2B-36A.............. 1, 2, Revision log 2, 1- FAA approved 01-12-77
5, 2-10, 5-10, 5-13, reissued 02-28-86
and 5-23. revision 6.
MU-2B-40............... 1, 2, Revision log 2, 1- FAA approved 3-2-78
5, 2-10, 5-10, 5-13, 5- reissued 03-25-86
14, and 5-24. revision 4.
MU-2B-60............... 1, 2, Revision log 2, 1- FAA approved 3-2-78
5, 2-9, 5-10, 5-13, 5- reissued 09-24-85
14, and 5-24. revision 5.
MU-2B-36 Modified by 1 through 31........... FAA approved 2-1-78
STC SA2413SW. reissued 12-18-92
revision 1.
------------------------------------------------------------------------
Since a situation exists that requires the immediate adoption of
this regulation, it is found that notice and opportunity for public
prior comment hereon are impracticable, and that good cause exists for
making this amendment effective in less than 30 days.
Comments Invited
Although this action is in the form of a final rule that involves
requirements affecting immediate flight safety and, thus, was not
preceded by notice and opportunity to comment, comments are invited on
this rule. Interested persons are invited to comment on this 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 will be considered,
and this rule may be amended in light of the comments received. Factual
information that supports the commenter's ideas and suggestions is
extremely helpful in evaluating the effectiveness of the AD action and
determining whether additional rulemaking action would be needed.
Comments are specifically invited on the overall regulatory,
economic, environmental, and energy aspects of the rule that might
suggest a need to modify the 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
AD 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. 94-CE-09-AD.'' The postcard will be date stamped and
returned to the commenter.
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.
The FAA has determined that this regulation is an emergency
regulation that must be issued immediately to correct an unsafe
condition in aircraft, and is not a ``significant regulatory action''
under Executive Order 12866. It has been determined further that this
action involves an emergency regulation under DOT Regulatory Policies
and Procedures (44 FR 11034, February 26, 1979). If it is determined
that this emergency regulation otherwise would be significant under DOT
Regulatory Policies and Procedures, a final regulatory evaluation will
be prepared and placed in the Rules Docket (otherwise, an evaluation is
not required). A copy of it, if filed, may be obtained from the Rules
Docket.
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. 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 a new airworthiness directive
to read as follows:
94-11-04 Mitsubishi Heavy Industries, Ltd.: Amendment 39-8920;
Docket No. 94-CE-09-AD.
Applicability: The following model and serial number airplanes,
certificated in any category:
------------------------------------------------------------------------
Model Serial No.
------------------------------------------------------------------------
MU-2B-26A............. All serial numbers.
MU-2B-36A............. All serial numbers.
MU-2B-40.............. All serial numbers.
MU-2B-60.............. All serial numbers.
MU-2B-36.............. All serial numbers modified by Supplemental Type
Certificate SA2413SW.
------------------------------------------------------------------------
Compliance: Required within the next 25 hours time-in-service
after the effective date of this AD, unless already accomplished.
To prevent propeller hub arm assembly failure because of high
vibration frequencies during ground idle speed and possible
separation of the propeller from the airplane, which could result in
loss of control of the airplane, accomplish the following:
(a) Adjust the underspeed governor minimum stop (ground idle) to
a range of 76.5 percent to 78.5 percent in accordance with the
Allied Signal Garrett Maintenance Manual (Report No. 72-00-95 for
TPE331-10-501M or Report No. 72-00-27 for TPE331-501M or -511M),
chapter 72-00-00, General-Adjustment /Test; and chapter 76-10-01,
Control Linkage Assembly, Maintenance Practices.
Note 1: One clockwise turn of the adjusting screw will increase
the ground idle engine speed approximately 5 percent.
(b) Modify the airframe condition control linkage by adjusting
Rod 1 and Levers 2 and 7 as specified in Figure 1 of this AD in
accordance with Chapter 6, Sec. 9.2, of the applicable Mitsubishi
MU-2 maintenance manual.
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E:\GRAPHICS\ER27MY94.008
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(c) Modify the tachometer indicator marking by accomplishing the
following:
(1) Apply red lacquer (Federal Standard 595a, number 11105 or
equivalent) to the tachometer indicator glass so that the red
operating arc extends to 76.5 percent.
Note 2: The red operating arc range will now be from 50 percent
to 76.5 percent.
(2) Using white lacquer (MIL-L-7178, color number 511 or
equivalent), apply a 1/16-inch wide by 1/4-inch long slip stripe
over the tachometer glass and indicator case at the 11:30 o'clock
position as specified in Figure 2 of this AD.
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E:\GRAPHICS\ER27MY94.009
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(d) Fabricate a placard with the following words utilizing
letters at least .10-inch in height: ``Minimum engine idle speed--
76.5 percent''. Install this placard on the instrument panel in
close proximity to the tachometer within the pilot's full view.
(e) Modifying the tachometer dial through an FAA-approved
instrument repair shop to extend the red operating arc to 76.5
percent is equivalent to those actions required by paragraph (c)(1),
(c)(2), and (d) of this AD, and may be accomplished in lieu of those
actions.
(f) Incorporate the following revision into the applicable
Airplane Flight Manual:
------------------------------------------------------------------------
Date and revision
Model Effective pages level
------------------------------------------------------------------------
MU-2B-26A.............. 1, 2, Revision Log 2, 1- FAA approved 1-12-77
5, 5-10, 5-13, and 5- reissued 03-25-86
23. revision 4.
MU-2B-36A.............. 1, 2, Revision Log 2, 1- FAA approved 01-12-77
5, 2-10, 5-10, 5-13, reissued 02-28-86
and 5-23. revision 6.
MU-2B-40............... 1, 2, Revision Log 2, 1- FAA approved 3-2-78
5, 2-10, 5-10, 5-13, 5- reissued 03-25-86
14, and 5-24.. revision 4.
MU-2B-60............... 1, 2, Revision Log 2, 1- FAA approved 3-2-78
5, 2-9, 5-10, 5-13, 5- reissued 09-24-85
14, and 5-24. revision 5.
MU-2B-36 modified by 1 through 31........... FAA approved 2-1-78
STC SA2413SW. reissued 12-18-92
revision 1.
------------------------------------------------------------------------
(g) Special flight permits may be issued in accordance with
Secs. 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.
(h) An alternative method of compliance other than that
referenced in paragraph (e) of this AD or adjustment of the
compliance time that provides an equivalent level of safety may be
approved by the Manager, Wichita Aircraft Certification Office
(ACO), 1801 Airport Road, room 100, Mid-Continent Airport, Wichita,
Kansas 67209. The request shall be forwarded through an appropriate
FAA Maintenance Inspector, who may add comments and then send it to
the Manager, Wichita ACO.
Note 3: Information concerning the existence of approved
alternative methods of compliance with this AD, if any, may be
obtained from the Wichita ACO.
(i) The incorporation required by this AD shall be done in
accordance with the following airplane flight manual revisions (as
applicable):
------------------------------------------------------------------------
Date and revision
Model Effective pages level
------------------------------------------------------------------------
MU-2B-26A.............. 1, 2, Revision log 2, 1- FAA approved 1-12-77
5, 5-10, 5-13, and 5- reissued 03-25-86
23. revision 4.
MU-2B-36A.............. 1, 2, revision log 2, 1- FAA approved 01-12-77
5, 2-10, 5-10, 5-13, reissued 02-28-86
and 5-23. revision 6.
MU-2B-40............... 1, 2, revision log 2, 1- FAA approved 3-2-78
5, 2-10, 5-10, 5-13, 5- reissued 03-25-86
14, and 5-24. revision 4.
MU-2B-60............... 1, 2, revision log 2, 1- FAA approved 3-2-78
5, 2-9, 5-10, 5-13, 5- reissued 09-24-85
14, and 5-24. revision 5.
MU-2B-36 modified by 1 through 31........... FAA approved 2-1-78
STC SA2413SW. reissued 12-18-92
revsion 1.
------------------------------------------------------------------------
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., 5-1 Marunouchi 2 Chome, Chiyoda-ku, Tokyo Japan. Copies may be
inspected at the FAA, Central Region, Office of the Assistant Chief
Counsel, room 1558, 601 E. 12th Street, Kansas City, Missouri, or at
the Office of the Federal Register, 800 North Capitol Street, NW.,
7th floor, suite 700, Washington, DC.
(j) This amendment (39-8920) becomes effective on June 10, 1994.
Issued in Kansas City, Missouri, on May 19, 1994.
Dwight A. Young,
Acting Manager, Small Airplane Directorate, Aircraft Certification
Service.
[FR Doc. 94-12717 Filed 5-26-94; 8:45 am]
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