[Federal Register Volume 71, Number 16 (Wednesday, January 25, 2006)]
[Proposed Rules]
[Pages 4072-4075]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E6-912]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2006-23578; Directorate Identifier 2006-CE-01-AD]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration (FAA), Department of 
Transportation (DOT).

ACTION: Notice of proposed rulemaking (NPRM).

-----------------------------------------------------------------------

SUMMARY: The FAA proposes to adopt a new airworthiness directive (AD) 
for all Mitsubishi Heavy Industries (MHI) MU-2B series airplanes. This 
proposed AD would require you to do the following: Remove and visually 
inspect the wing attach barrel nuts, bolts, and retainers for cracks, 
corrosion, and fractures; replace any cracked, corroded, or fractured 
parts; inspect reusable barrel nuts and bolts for deformation and 
irregularities in the threads; replace any deformed or irregular parts; 
and install new or reusable parts and torque to the correct value. This 
proposed AD results from a recent safety evaluation that used a data-
driven approach to evaluate the design, operation, and maintenance of 
the MU-2B series airplanes in order to determine their safety and 
define what steps, if any, are necessary to ensure their safe 
operation. Part of that evaluation was the identification of unsafe 
conditions that exist or could develop on the affected type design 
airplanes. We are issuing this proposed AD to detect and correct 
cracks, corrosion, fractures, and incorrect torque values in the wing 
attach barrel nuts, which could result in failure of the wing barrel 
nuts and/or associated wing attachment hardware. This failure could 
lead to in-flight separation of the outer wing from the center wing 
section and result in loss of controlled flight.

DATES: We must receive comments on this proposed AD by February 27, 
2006.

ADDRESSES: Use one of the following addresses to comment on this 
proposed AD:
     DOT Docket Web site: Go to http://dms.dot.gov and follow 
the instructions for sending your comments electronically.
     Government-wide rulemaking Web site: Go to http://www.regulations.gov and follow the instructions for sending your 
comments electronically.
     Mail: Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-401, 
Washington, DC 20590.
     Fax: 1-202-493-2251.
     Hand Delivery: Room PL-401 on the plaza level of the 
Nassif Building, 400 Seventh Street, SW., Washington, DC, between 9 
a.m. and 5 p.m., Monday through Friday, except Federal holidays.
    Contact Mitsubishi Heavy Industries, Ltd., Nagoya Aerospace Systems 
Works, 10, OYE-CHO, Minato-Ku, Nagoya, Japan, or Turbine Aircraft 
Services, Inc., 4550 Jimmy Doolittle Drive, Addison, Texas 75001; 
telephone: (972) 248-3108; facsimile: (972) 248-3321, for the service 
information identified in this proposed AD.
    You may examine the comments on this proposed AD in the AD docket 
on the Internet at http://dms.dot.gov.

FOR FURTHER INFORMATION CONTACT: Andrew McAnaul, Aerospace Engineer, 
ASW-150 (c/o MIDO-43), 10100 Reunion Place, Suite 650, San Antonio, 
Texas 78216; telephone: (210) 308-3365; facsimile: (210) 308-3370.

SUPPLEMENTARY INFORMATION: 

Comments Invited

    How do I comment on this proposed AD? We invite you to send any 
written relevant data, views, or arguments regarding this proposal. 
Send your comments to an address listed under ADDRESSES. Include the 
docket number, ``FAA-2006-23578; Directorate Identifier 2006-CE-01-AD'' 
at the beginning of your comments. We specifically invite comments on 
the overall regulatory, economic, environmental, and energy aspects of 
the proposed AD. We will consider all comments received by the closing 
date and may amend the proposed AD in light of those comments.
    We will post all comments we receive, without change, to http://dms.dot.gov, including any personal information you provide. We will 
also post a report summarizing each substantive verbal contact with FAA 
personnel concerning this proposed rulemaking. Using the search 
function of the DOT docket web site, anyone can find and read the 
comments received into any of our dockets, including the name of the 
individual who sent the comment (or signed the comment on behalf of an 
association, business, labor union, etc.). You may review the DOT's 
complete Privacy Act Statement in the Federal Register published on 
April 11, 2000 (65 FR 19477-78) or you may visit http://dms.dot.gov.

Examining the Dockets

    Where can I go to view the docket information? You may examine the 
docket that contains the proposal, any comments received and any final 
disposition on the Internet at http://dms.dot.gov, or in person at the 
DOT Docket Offices between 9 a.m. and 5 p.m., Monday through Friday, 
except Federal holidays. The Docket Office (telephone 1-800-647-5227) 
is located on the plaza level of the Department of Transportation 
NASSIF Building at the street address stated in ADDRESSES. Comments 
will be available in the AD docket shortly after the Docket Management 
Facility receives them.

Discussion

    What events have caused this proposed AD? Recent accidents and the 
service history of the Mitsubishi MU-2B series airplanes prompted FAA 
to conduct an MU-2B Safety Evaluation. This evaluation used a data-
driven approach to evaluate the design, operation, and maintenance of 
MU-2B series airplanes in order to determine their safety and define 
what steps, if any, are necessary to ensure their safe operation.
    The safety evaluation provided an in-depth review and analysis of 
MU-2B incidents, accidents, safety data, pilot training requirements, 
engine reliability, and commercial operations. In conducting this 
evaluation, the team employed new analysis tools that provided a much 
more detailed root cause analysis of the MU-2B problems than was 
previously possible.
    Part of that evaluation was to identify unsafe conditions that 
exist or could develop on the affected type design airplanes. One of 
these conditions is the discovery of the right wing upper forward and 
lower forward barrel nuts found cracked during a scheduled 7,500-hour 
inspection on one of the affected airplanes. The manufacturer conducted 
additional investigations of the barrel nuts on other affected 
airplanes. The result of this investigation revealed no other cracked 
barrel nuts. However, it was discovered that several airplanes had 
over-torqued barrel nuts, which could result in cracking.

[[Page 4073]]

    What is the potential impact if FAA took no action? This condition, 
if not detected and corrected, could result in failure of the wing 
barrel nuts and/or associated wing attachment hardware. This failure 
could lead to in-flight separation of the outer wing from the center 
wing section and result in loss of controlled flight.

Relevant Service Information

    Is there service information that applies to this subject? We have 
reviewed Mitsubishi Heavy Industries, Ltd. MU-2 Service Bulletin 
referenced as JCAB T.C.: No. 241, dated July 14, 2004, and MU-2 Service 
Bulletin referenced as FAA T.C.: No. 103/57-004, dated August 2, 2004.
    What are the provisions of this service information? These service 
bulletins describe procedures for:
     Removing and inspecting the wing attach barrel nuts and 
retainer for cracks, corrosion, and fractures;
     Replacing any wing attach barrel nuts and retainer with 
cracks, corrosion, or fractures;
     Inspecting any bolts or barrel nuts to be reused for 
deformation or irregularities in the threads;
     Replacing any bolts or barrel nuts with deformation or 
irregularities in the threads; and
     Reinstalling the wing attach barrel nuts and hardware to 
the correct torque value.
    Since Japan is the State of Design for the affected airplanes on 
one of the two type certificates, did the Japan Civil Airworthiness 
Board (JCAB) take any action? The MU-2B series airplane was initially 
certificated in 1965 and again in 1976 under two separate type 
certificates that consist of basically the same type design. Japan is 
the State of Design for TC No. A2PC, and the United States is the State 
of Design for TC No. A10SW. The affected models are as follows (where 
models are duplicated, specific serial numbers are specified in the 
individual TCs):

------------------------------------------------------------------------
           Type certificate                     Affected models
------------------------------------------------------------------------
A10SW................................  MU-2B-25, MU-2B-26, MU-2B-26A, MU-
                                        2B-35, MU-2B-36, MU-2B-36A, MU-
                                        2B-40, and MU-2B-60.
A2PC.................................  MU-2B, MU-2B-10, MU-2B-15, MU-2B-
                                        20, MU-2B-25, MU-2B-26, MU-2B-
                                        30, MU-2B-35, and MU-2B-36.
------------------------------------------------------------------------

    The JCAB approved Mitsubishi Heavy Industries, Ltd. MU-2 Service 
Bulletin referenced as JCAB T.C.: No. 241, dated July 14, 2004, and MU-
2 Service Bulletin referenced FAA T.C.: No. 103/57-004, dated August 2, 
2004, to ensure the continued airworthiness of these airplanes in 
Japan.

FAA's Determination and Requirements of the Proposed AD

    Why have we determined AD action is necessary and what would this 
proposed AD require? We are proposing this AD to address an unsafe 
condition that we determined is likely to exist or develop on other 
products of this same type design. This proposed AD would require you 
to do the following:
     Remove and visually inspect the wing attach barrel nuts, 
bolts, and retainers for cracks, corrosion, and fractures;
     Replace any cracked, corroded, or fractured wing attach 
barrel nuts, bolts, and retainers with new parts;
     Inspect reusable barrel nuts and bolts for deformation and 
irregularities in the threads; replace any deformed or irregular wing 
attach barrel nuts or bolts with new parts; and
     Install new or reusable parts and torque to the correct 
value.
    This proposed AD would require you to use the service information 
described previously to perform these actions.

Costs of Compliance

    How many airplanes would this proposed AD impact? We estimate that 
this proposed AD affects 397 airplanes in the U.S. registry.
    What would be the cost impact of this proposed AD on owners/
operators of the affected airplanes? We estimate the following costs to 
do the proposed inspection:

----------------------------------------------------------------------------------------------------------------
                                                         Total cost per
            Labor cost                   Parts cost         airplane          Total cost on U.S.  operators
----------------------------------------------------------------------------------------------------------------
1 work hour x $65 per hour = $65..  N/A................             $65  $65 x 397 = $25,805.
----------------------------------------------------------------------------------------------------------------

    We estimate the following costs to do any necessary replacements 
that would be required based on the results of the proposed inspection. 
We have no way of determining the number of airplanes that may need 
this replacement:

----------------------------------------------------------------------------------------------------------------
                                                                       Total cost per airplane to replace all 8
              Labor cost                         Parts cost                           barrel nuts
----------------------------------------------------------------------------------------------------------------
11 work hours x $65 per hour = $715..  $60 for each barrel nut.       $715 + $480 = $1,195.
                                        There are 8 barrel nuts on
                                        each airplane.
                                       Possible total cost of: $60 x
                                        8 = $480..
----------------------------------------------------------------------------------------------------------------

    Are there other actions that FAA is issuing that would present a 
cost impact on the MU-2B series airplane fleet? This is one of several 
actions that FAA is evaluating for unsafe conditions on the MU-2B 
airplanes. To date, this is the first proposed AD action to be taken.

Authority for This Rulemaking

    What authority does FAA have for issuing this rulemaking action? 
Title 49 of the United States Code specifies the FAA's authority to 
issue rules on aviation safety. Subtitle I, Section 106, describes the 
authority of the FAA Administrator. Subtitle VII, Aviation Programs, 
describes in more detail the scope of the Agency's authority.
    We are issuing this rulemaking under the authority described in 
Subtitle VII, Part A, Subpart III, Section 44701, ``General 
requirements.'' Under that section, Congress charges the FAA with 
promoting safe flight of civil aircraft in air commerce by prescribing 
regulations for practices, methods, and procedures the Administrator 
finds necessary for safety in air commerce. This regulation

[[Page 4074]]

is within the scope of that authority because it addresses an unsafe 
condition that is likely to exist or develop on products identified in 
this rulemaking action.

Regulatory Findings

    Would this proposed AD impact various entities? We have determined 
that this proposed AD would not have federalism implications under 
Executive Order 13132. This proposed AD would not have a substantial 
direct effect 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.
    For the reasons discussed above, I certify that the 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. 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.
    We prepared a regulatory evaluation of the estimated costs to 
comply with this proposed AD. See the ADDRESSES section for a location 
to examine the regulatory evaluation.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, under the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 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. The Federal Aviation Administration (FAA) amends Sec.  39.13 by 
adding the following new airworthiness directive (AD):

Mitsubishi Heavy Industries, Ltd.: Docket No. FAA-2006-23578; 
Directorate Identifier 2006-CE-01-AD.

When Is the Last Date I Can Submit Comments on This Proposed AD?

    (a) The FAA must receive comments on this AD action by February 
27, 2006.

What Other ADs Are Affected by This Action?

    (b) None.

What Airplanes Are Affected by This AD?

    (c) This AD affects the following Mitsubishi Heavy Industries, 
Ltd. airplane models and serial numbers that are certificated in any 
category:

------------------------------------------------------------------------
                    Model                            Serial numbers
------------------------------------------------------------------------
MU-2B-10.....................................  101 through 347 (Except
                                                313 and 321).
MU-2B-15.....................................  101 through 347 (Except
                                                313 and 321).
MU-2B-20.....................................  101 through 347 (Except
                                                313 and 321).
MU-2B-25.....................................  101 through 347 (Except
                                                313 and 321), 313SA,
                                                321SA, and 348SA through
                                                394SA.
MU-2B-26.....................................  101 through 347 (Except
                                                313 and 321), 313SA,
                                                321SA, and 348SA through
                                                394SA.
MU-2B-26A....................................  313SA, 321SA, and 348SA
                                                through 394SA.
MU-2B-30.....................................  501 through 696 (Except
                                                652 and 661).
MU-2B-35.....................................  501 through 696 (Except
                                                652 and 661), 652SA,
                                                661SA, and 697SA through
                                                730SA.
MU-2B-36.....................................  501 through 696 (Except
                                                652 and 661), 652SA,
                                                661SA, and 697SA through
                                                730SA.
MU-2B-36A....................................  652SA, 661SA, and 697SA
                                                through 730SA.
------------------------------------------------------------------------

What Is the Unsafe Condition Presented in This AD?

    (d) This AD results from a recent safety evaluation that used a 
data-driven approach to evaluate the design, operation, and 
maintenance of the MU-2B series airplanes in order to determine 
their safety and define what steps, if any, are necessary to ensure 
their safe operation. Part of that evaluation was to identify unsafe 
conditions that exist or could develop on the affected type design 
airplanes. The actions specified in this AD are intended to detect 
and correct cracks, corrosion, fractures, and incorrect torque 
values in the wing attach barrel nuts, which could result in failure 
of the wing barrel nuts and/or associated wing attachment hardware. 
This failure could lead to in-flight separation of the outer wing 
from the center wing section and result in loss of controlled 
flight.

What Must I Do To Address This Problem?

    (e) To address this problem, you must do the following, unless 
already done:

------------------------------------------------------------------------
           Actions                 Compliance            Procedures
------------------------------------------------------------------------
(1) Remove each wing attach   Within the next 200   Follow Mitsubishi
 barrel nut, bolt, and         hours time-in-        Heavy Industries,
 retainer and do a detailed    service (TIS) or 12   Ltd. MU-2 Service
 visual inspection for         months after the      Bulletins
 cracks, corrosion, and        effective date of     referenced as JCAB
 fractures.                    this AD, whichever    T.C.: No. 241,
                               occurs first,         dated July 14,
                               unless already done.  2004, and FAA T.C.:
                                                     No. 103/57-004,
                                                     dated August 2,
                                                     2004, as
                                                     applicable.
(2) If any signs of cracks,   Before further        Follow Mitsubishi
 corrosion, or fractures are   flight after the      Heavy Industries,
 found on any wing attach      inspection required   Ltd. MU-2 Service
 barrel nut during the         in paragraph (e)(1)   Bulletins
 inspection required in        of this AD, unless    referenced as JCAB
 paragraph (e)(1) of this      already done.         T.C.: No. 241,
 AD, replace that wing                               dated July 14,
 attach barrel nut, bolt,                            2004, and FAA T.C.:
 and retainer with new parts                         No. 103/57-004,
 and install to the correct                          dated August 2,
 torque value.                                       2004, as
                                                     applicable, and the
                                                     appropriate
                                                     maintenance manual.

[[Page 4075]]

 
(3) If no signs of cracks,    Before further        Follow Mitsubishi
 corrosion, or fractures are   flight after the      Heavy Industries,
 found during the inspection   inspection required   Ltd. MU-2 Service
 required in paragraph         in paragraph (e)(1)   Bulletins
 (e)(1) of this AD, you may    of this AD, unless    referenced as JCAB
 reuse the barrel nuts and     already done.         T.C.: No. 241,
 bolts if they have been                             dated July 14,
 inspected and are free of                           2004, and FAA T.C.:
 deformation and                                     No. 103/57-004,
 irregularities in the                               dated August 2,
 threads. Reinstall                                  2004, as
 inspected parts to the                              applicable, and the
 correct torque value. If                            appropriate
 the barrel nuts and bolts                           maintenance manual.
 are not free of deformation
 and irregularities in the
 threads, install new parts
 to the correct torque value.
------------------------------------------------------------------------

May I Request an Alternative Method of Compliance?

    (f) The Manager, Fort Worth Airplane Certification Office, FAA, 
has the authority to approve alternative methods of compliance for 
this AD, if requested using the procedures found in 14 CFR 39.19.
    (g) For information on any already approved alternative methods 
of compliance or for information pertaining to this AD, contact 
Andrew McAnaul, Aerospace Engineer, ASW-150 (c/o MIDO-43), 10100 
Reunion Place, Suite 650, San Antonio, Texas 78216; telephone: (210) 
308-3365; facsimile: (210) 308-3370.

Is There Other Information That Relates to This Subject?

    (h) Mitsubishi Heavy Industries, Ltd. MU-2 Service Bulletins 
JCAB T.C.: No. 241, dated July 14, 2004, and FAA T.C.: No. 103/57-
004, dated August 2, 2004, pertain to the subject of this AD.

May I Get Copies of the Documents Referenced in This AD?

    (i) To get copies of the documents referenced in this AD, 
contact Mitsubishi Heavy Industries, Ltd., Nagoya Aerospace Systems 
Works, 10, OYE-CHO, Minato-Ku, Nagoya, Japan, or Turbine Aircraft 
Services, Inc., 4550 Jimmy Doolittle Drive, Addison, Texas 75001; 
telephone: (972) 248-3108; facsimile: (972) 248-3321. To view the AD 
docket, go to the Docket Management Facility; U.S. Department of 
Transportation, 400 Seventh Street, SW., Nassif Building, Room PL-
401, Washington, DC, or on the Internet at http://dms.dot.gov. The 
docket number is Docket No. FAA-2006-23578; Directorate Identifier 
2006-CE-01-AD.

    Issued in Kansas City, Missouri, on January 19, 2006.
John R. Colomy,
Acting Manager, Small Airplane Directorate, Aircraft Certification 
Service.
[FR Doc. E6-912 Filed 1-24-06; 8:45 am]
BILLING CODE 4910-13-P