[Federal Register Volume 62, Number 38 (Wednesday, February 26, 1997)]
[Proposed Rules]
[Pages 8648-8650]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-4718]


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DEPARTMENT OF TRANSPORTATION
14 CFR Part 39

[Docket No. 96-NM-210-AD]
RIN 2120-AA64


Airworthiness Directives; Mitsubishi Model MU-300 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 MU-300 
airplanes. This proposal would require revising the Airplane Flight 
Manual (AFM) to provide pilots with certain operating procedures during 
icing conditions, and to limit the maximum flaps position for flight in 
icing conditions or landing after an icing encounter. The proposal also 
would require installing an ice detector, and accomplishing a 
corresponding AFM revision to address its operation. For certain 
airplanes, the proposal would require converting the airplane 
configuration or modifying the warning horn system of the landing gear; 
and revising the AFM to specify flaps 10 degrees as a normal landing 
flap configuration. The actions specified by the proposed AD are 
intended to prevent uncommanded nose-down pitch at certain flap 
settings during icing conditions.

DATES: Comments must be received by April 7, 1997.

ADDRESSES: Submit comments in triplicate to the Federal Aviation 
Administration (FAA), Transport Airplane Directorate, ANM-103, 
Attention: Rules Docket No. 96-NM-210-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 Mitsubishi Heavy Industries America, Inc., 15303 Dallas 
Parkway, Suite 685, LB-77, Dallas, Texas 75248. This information may be 
examined at the FAA, Transport Airplane Directorate, 1601 Lind Avenue, 
SW., Renton, Washington; or at the FAA, Small Airplane Directorate, 
Wichita Aircraft Certification Office, 1801 Airport Road, Room 100, 
Mid-Continent Airport, Wichita, Kansas.

FOR FURTHER INFORMATION CONTACT: Tina L. Miller, Aerospace Engineer, 
Flight Test Branch, ACE-117W, FAA, Wichita Aircraft Certification 
Office, Small Airplane Directorate, 1801 Airport Road, Room 100, Mid-
Continent Airport, Wichita, Kansas 67209; telephone (316) 946-4168; fax 
(316) 946-4407.

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 96-NM-210-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-103, Attention: Rules 
Docket No. 96-NM-210-AD, 1601 Lind Avenue, SW., Renton, Washington 
98055-4056.

Discussion

    On December 5, 1994, the FAA issued AD 94-25-10, amendment 39-9094 
(59 FR 64112, December 13, 1994), that is applicable to all Raytheon 
(Beech) Model 400, 400A, 400T, and MU-300-10 airplanes, and all 
Mitsubishi Model MU-300 airplanes, to require a revision to the FAA-
approved Airplane Flight Manual (AFM) to provide pilots with special 
operating procedures during icing conditions. That AD was prompted by 
results of icing tests, which demonstrated that ice accumulations on 
the horizontal stabilizer may cause the airplane to pitch down at 
certain flaps settings. The requirements of that AD are intended to 
prevent uncommanded nose-down pitch at certain flap settings during 
icing conditions.

Actions Since Issuance of Previous Rule

    Since the issuance of AD 94-25-10, the FAA reviewed and approved 
Mitsubishi MU-300 Service Bulletin No. 30-007 (including Attachment 1), 
dated January 12, 1996. The service bulletin describes procedures for 
installing a Rosemount ice detector in accordance with Supplemental 
Type Certificate (STC) ST00383WI.
    For Diamond I airplanes, Attachment 1 of the service bulletin 
describes procedures for modifying the warning horn system of the 
landing gear. That action involves modifying the center pedestal and 
the wiring of the warning horn, installing a switch panel assembly on 
the center pedestal, and performing a functional test of the warning 
horn system of the landing gear.
    As an alternative to this modification, the service bulletin 
specifies that Diamond I airplanes may be converted to the Diamond IA 
airplane configuration by accomplishing Mitsubishi MU-300 Diamond 
Service Recommendation SR-001, Revision 2, dated June 1, 1984. That 
action involves upgrading the airplane to conform to an improved 
performance configuration, and includes modifications of the air 
conditioning system, the pitch trim indicator, the warning horn of the 
landing gear, and the engine indicating system.
    Mitsubishi MU-300 Service Bulletin No. 30-007 also references the 
following documents as the additional sources of service information 
for accomplishment of certain other procedures:

    1. Airplane Flight Manual Supplement M300-1003, dated December 
6, 1995, which revises the Introduction, Operating Limitations, 
Emergency Procedures, Abnormal Procedures, Normal Procedures, 
Performance, and Weight and Balance Sections of the AFM to address 
the operation of the ice detector system.
    2. Diamond I Flight Manual, Revision 29, dated January 5, 1996, 
which revises the

[[Page 8649]]

Operating Limitations, Emergency Procedures, Abnormal Procedures, 
Normal Procedures, Performance, and Weight and Balance Sections of 
the AFM to limit the maximum flap position to flaps 10 degrees for 
flight in icing conditions or landing after an icing encounter, to 
allow landing flaps of 30 degrees if the icing encounter meets 
certain criteria, and to specify flaps 10 degrees as a normal 
landing flap configuration for Diamond I airplanes.
    3. Mitsubishi MU-300 Diamond IA Airplane Flight Manual, Revision 
9, dated January 5, 1996, which revises the Operating Limitations, 
Emergency Procedures, Abnormal Procedures, Normal Procedures, and 
Performance Sections of the AFM to limit the maximum flap position 
to flaps 10 degrees for flight in icing conditions or landing after 
an icing encounter, and to allow landing flaps of 30 degrees if the 
icing encounter meets certain criteria.

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, for Model MU-300 airplanes, the proposed AD would 
continue to require the AFM revision, currently required by AD, that 
provides pilots with certain operating procedures during icing 
conditions, and limits the maximum flaps position for flight in icing 
conditions or landing after an icing encounter. This proposal also 
would require installing an ice detector, and accomplishing a 
corresponding AFM revision to address its operation.
    For certain airplanes, the proposal would require converting the 
airplane configuration or modifying the warning horn system of the 
landing gear; and revising the AFM to specify flaps 10 degrees as a 
normal landing flap configuration.
    The proposed actions would be required to be accomplished in 
accordance with the service documents described previously.
    Accomplishment of the requirements of the proposed AD would 
constitute terminating action for the requirements of AD 94-25-10 for 
Model MU-300 airplanes.

Other Relevant Rulemaking

    The FAA is considering issuing separate rulemaking action to 
supersede AD 94-25-10 to remove Model MU-300 airplanes from the 
applicability of the AD. That separate rulemaking action also would 
require, among other things, modification of the ice protection system 
of the horizontal stabilizer on all Beech Model 400, 400A, 400T, and 
MU-300-10 airplanes.

Difference Between Service Bulletin and the Proposed AD

    Operators should note that Mitsubishi MU-300 Service Bulletin No. 
30-007 recommends a compliance time of one year after the date of 
issuance of the service bulletin. However, this proposed AD requires 
that the actions specified in the service bulletin be accomplished 
within two years after the effective date of the AD. The FAA 
established the proposed two-year compliance time to coincide with the 
time specified in the separate rulemaking action to supersede AD 94-25-
10 for Beech Model 400, 400A, 400T, and MU-300-10 airplanes, discussed 
previously. The FAA has determined that the proposed 2-year compliance 
time will not compromise safety, since the currently-required AFM 
revision will remain in effect in the interim.

Cost Impact

    The FAA estimates that 89 Model MU-300 airplanes of U.S. registry 
would be affected by this proposed AD.
    The AFM revision that is currently required by AD 94-25-10 for 
Model MU-300 airplanes takes approximately 1 work hour per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact on U.S. operators of the currently 
required AFM revision is estimated to be $5,340, or $60 per airplane.
    The ice detector installation that is proposed in this AD action 
for all airplanes would take approximately 80 work hours per airplane 
to accomplish, at an average labor rate of $60 per work hour. Required 
parts would cost approximately $7,000 per airplane. Based on these 
figures, the cost impact on U.S. operators of the proposed installation 
of this AD is estimated to be $1,050,200, or $11,800 per airplane.
    The new AFM revisions that are proposed in this AD action for all 
airplanes would take approximately 1 work hour per airplane to 
accomplish, at an average labor rate of $60 per work hour. Based on 
these figures, the cost impact on U.S. operators of the new AFM 
revisions is estimated to be $5,340, or $60 per airplane.
    The conversion of the configuration of the airplane that is 
specified in this AD action as an option for Diamond I airplanes, if 
accomplished, requires actions related to the airframe and the engine. 
The airframe portion of the conversion would take approximately 160 
work hours per airplane to accomplish, at an average labor rate of $60 
per work hour. Required parts would cost approximately $50,000 per 
airplane. The engine portion of the conversion should be accomplished 
during a regular engine overhaul; therefore, it would require no 
additional work hours. Required parts for this action would cost 
approximately $260,000 per airplane. Based on these figures, the cost 
impact of the proposed conversion on U.S. operators, who elect to 
accomplish it, is estimated to be $319,600 per airplane.
    If accomplished, the option for modification of the warning horn 
system that is specified in this AD action for Diamond I airplanes 
would take approximately 6 work hours per airplane to accomplish, at an 
average labor rate of $60 per work hour. Required parts would cost 
approximately $600 per airplane. Based on these figures, the cost 
impact of the proposed modification on U.S. operators is estimated to 
be $960 per airplane.
    The cost impact figures discussed above are 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 
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.

[[Page 8650]]

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:

Mitsubishi Heavy Industries, LTD.: Docket 96-NM-210-AD.

    Applicability: All Model MU-300 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 
otherwise 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 (e) 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 uncommanded nose-down pitch at certain flap settings 
during icing conditions, accomplish the following:
    (a) For all airplanes: Within 20 days after December 28, 1994 
(the effective date of AD 94-25-10, amendment 39-9094), revise the 
Limitations Section and Normal Procedures Section of the FAA-
approved Airplane Flight Manual (AFM) to include the following 
statement. This may be accomplished by inserting a copy of this AD 
in the AFM.

``Icing Conditions

    If icing conditions are encountered during flight, no greater 
than 10 degrees flaps may be utilized for landing unless the 
following conditions are met:
    1. The icing conditions were encountered for less than 10 
minutes, and the Ram Air Temperature (RAT) during such encounter was 
warmer than -8 degrees C. or
    2. A RAT of +5 degrees C or warmer is observed during approach 
and landing.
    If either of the above two conditions are met, 30 degrees flaps 
may be utilized for landing.
    Otherwise:

Flaps (landing flaps setting)--10 degrees
Land Select (LAND SEL) Switch--Flaps 10 degrees

    Use landing data for 10 degrees flaps from Appendix 1 of this 
AD.
    Use landing data for 10 degrees flaps from Section 6, 
Performance.
    (b) For Diamond I airplanes, as identified in Mitsubishi MU-300 
Service Bulletin No. 30-007, dated January 12, 1996: Within 2 years 
after the effective date of this AD, accomplish the requirements of 
paragraphs (b)(1) through (b)(4) of this AD:
    (1) Install an ice detector in accordance with Mitsubishi MU-300 
Service Bulletin No. 30-007, dated January 12, 1996.
    (2) Revise the Introduction, Operating Limitations, Emergency 
Procedures, Abnormal Procedures, Normal Procedures, Performance, and 
Weight and Balance Sections of the FAA-approved AFM to address the 
operation of the ice detector system. This may be accomplished by 
inserting a copy of Airplane Flight Manual Supplement M300-1003, 
dated December 6, 1995, in the AFM.
    (3) Accomplish either paragraph (b)(3)(i) or (b)(3)(ii) of this 
AD.
    (i) Convert the airplane from the Diamond I configuration to the 
Diamond IA configuration in accordance with Mitsubishi MU-300 
Diamond Service Recommendation SR 71-001, Revision 2, dated June 1, 
1984; and accomplish the AFM revision required by paragraph (c)(3) 
of this AD, or
    (ii) Modify the warning horn system of the landing gear in 
accordance with Attachment 1 of Mitsubishi MU-300 Service Bulletin 
No. 30-007, dated January 12, 1996.
    (4) Revise the Operating Limitations, Emergency Procedures, 
Abnormal Procedures, Normal Procedures, Performance, and Weight and 
Balance Sections of the AFM to limit the maximum flap position to 
flaps 10 degrees for flight in icing conditions or landing after an 
icing encounter, to allow landing flaps of 30 degrees if the icing 
encounter meets certain criteria, and to specify flaps 10 degrees as 
a normal landing flap configuration. This may be accomplished by 
inserting a copy of Diamond I Flight Manual, Revision 29, dated 
January 5, 1996, in the AFM.
    (c) For Diamond IA airplanes: Within 2 years after the effective 
date of this AD, accomplish the requirements of paragraphs (c)(1), 
(c)(2), and (c)(3) of this AD.
    (1) Install an ice detector in accordance with Mitsubishi MU-300 
Service Bulletin No. 30-007, dated January 12, 1996.
    (2) Revise the Introduction, Operating Limitations, Emergency 
Procedures,
    Abnormal Procedures, Normal Procedures, Performance, and Weight 
and Balance Sections of the FAA-approved AFM to address the 
operation of the ice detector system. This may be accomplished by 
inserting a copy of Airplane Flight Manual Supplement M300-1003, 
dated December 6, 1995, in the AFM.
    (3) Revise the Operating Limitations, Emergency Procedures, 
Abnormal Procedures, Normal Procedures, and Performance Sections of 
the AFM to limit the maximum flap position to flaps 10 degrees for 
flight in icing conditions or landing after an icing encounter, and 
to allow landing flaps of 30 degrees if the icing encounter meets 
certain criteria. This may be accomplished by inserting a copy of 
Mitsubishi MU-300 Diamond IA Airplane Flight Manual, Revision 9, 
dated January 5, 1996, in the AFM.
    (d) Accomplishment of the requirements of paragraph (b) or (c) 
of this AD, as applicable, constitutes terminating action for the 
requirements of AD 94-25-10, amendment 39-9094 [and paragraph (a) of 
this AD.] Following accomplishment of paragraph (b) or (c) of this 
AD, as applicable, the AFM revision required by paragraph (a) of 
this AD may be removed from the AFM.
    (e) 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, Wichita Aircraft Certification 
Office (ACO), FAA, Small 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, Wichita ACO.

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

    (f) 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.

    Issued in Renton, Washington, on February 20, 1997.
James V. Devany,
Acting Manager, Transport Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. 97-4718 Filed 2-25-97; 8:45 am]
BILLING CODE 4910-13-U