[Federal Register Volume 65, Number 94 (Monday, May 15, 2000)]
[Rules and Regulations]
[Pages 30865-30874]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 00-11863]


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

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97-CE-21-AD; Amendment 39-11724; AD 2000-09-15]
RIN 2120-AA64


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

AGENCY: Federal Aviation Administration, DOT.

ACTION: Final rule.

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

SUMMARY: This amendment adopts a new airworthiness directive (AD) that 
applies to all Mitsubishi Heavy Industries, Ltd. (Mitsubishi) MU-2B 
series airplanes. This AD requires modifying the airplanes' operating 
systems. This AD results from several icing-related incidents and 
accidents of MU-2B series airplanes, and the Federal Aviation 
Administration's investigation of the airplane design and pilot's 
ability to operate in icing conditions. The actions specified by this 
AD are intended to assist in preventing departure from controlled 
flight while operating in icing conditions.

DATES: This AD becomes effective on July 24, 2000.
    The Director of the Federal Register approved the incorporation by 
reference of certain publications listed in the regulation as of July 
24, 2000.

ADDRESSES: You may get the service information referenced in this AD 
from Mitsubishi Heavy Industries America, Inc., 15303 Dallas Parkway, 
suite 685, LB-77, Dallas, Texas 75248; telephone: (972) 980-5001; 
facsimile: (972) 980-5091. You may examine this information at FAA, 
Central Region, Office of the Regional Counsel, Attention: Rules Docket 
No. 97-CE-21-AD, 901 Locust, Room 506, 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: Contact one of the following for 
questions or more information related to this subject: Mr. John Dow, 
Aerospace Engineer, Small Airplane Directorate, FAA, 901 Locust, Room 
301, Kansas City, Missouri 64106, telephone: (816) 329-4121; facsimile: 
(816) 426-4090; Mr. Carl Fountain, Aerospace Engineer, Los Angeles 
Aircraft Certification Office, FAA, 3960 Paramount Blvd., Lakewood, 
California 90712; telephone:

[[Page 30866]]

(562) 627-5222; facsimile: (562) 627-5228; or Ms. Alma Ramirez-Hodge, 
Aerospace Engineer, FAA, Airplane Certification Office, 2601 Meacham 
Boulevard, Fort Worth, Texas 76193-0150; telephone: (817) 222-5147; 
facsimile: (817) 222-5960.

SUPPLEMENTARY INFORMATION:  

Events Leading to the Issuance of This AD

What caused this AD?

    This AD is the result of several icing-related incidents and 
accidents of MU-2B series airplanes, and FAA's investigation of both 
the airplane design and pilot's ability to operate in icing conditions.

Has FAA taken any action to this point?

    We issued a proposal to amend part 39 of the Federal Aviation 
Regulations (14 CFR part 39) to include an AD that would apply to all 
Mitsubishi MU-2B series airplanes. This proposal was published in the 
Federal Register as a notice of proposed rulemaking (NPRM) on May 21, 
1998 (63 FR 27872). The NPRM proposed to require you to incorporate the 
following modifications on the airplane's operating systems:
    (1) An ice detection system;
    (2) A deice monitoring system;
    (3) An automatic autopilot disconnect system and a trim-in-motion 
alert system;
    (4) An engine continuous-duty ignition replacement system; and
    (5) An auto-ignition (re-light) system.
    The NPRM also proposed to require you to fabricate a placard (using 
\1/8\-inch letters) with the following words and proposed to require 
you to install this placard within the pilot's clear view:
    ``Prior to the first flight of each day, a negative torque sensing 
(NTS) check and a Propeller Feather Valve check must be performed in 
accordance with the Normal Checklist Procedures.''
    Accomplishment of the proposed actions as specified in the NPRM 
would be required in accordance with:
    <bullet> Mitsubishi MU-2 Service Bulletin (SB) No. 217, Revision B, 
dated November 7, 1996;
    <bullet> Mitsubishi MU-2 SB No. 226, which incorporates the 
following pages:

----------------------------------------------------------------------------------------------------------------
                  Pages                            Revision level                           Date
----------------------------------------------------------------------------------------------------------------
2 through 11, 13 through 24, 27 through   A...............................  January 13, 1997.
 57, and 59 through 93.
1, 12, 24, 25, 26, and 58...............  B...............................  February 27, 1997.
----------------------------------------------------------------------------------------------------------------

    <bullet> Mitsubishi MU-2 SB No. 231, dated July 2, 1997, Mitsubishi 
MU-2 SB No. 232, dated July 2, 1997;
    <bullet> Mitsubishi MU-2B SB No. 074/74-001, dated October 9, 1991;
    <bullet> Test Instrumentation, Inc. Document No. MU2-1001, Rev. C, 
dated June 15, 1997;
    <bullet> Test Instrumentation, Inc. Document No. MU2-4001, Rev. C, 
dated June 30, 1997;
    <bullet> Test Instrumentation, Inc. Document No. MU2-5001, Rev. E., 
dated May 21, 1997; and
    <bullet> Test Instrumentation, Inc. Document No. MU2-6005, dated 
September 28, 1997.

Was the Public Invited To Comment?

    Interested persons were afforded an opportunity to participate in 
the making of this amendment through the following avenues:
    <bullet> Comments to the Docket file in accordance with the 
procedures specified in the NPRM; and
    <bullet> Communications with FAA at a public meeting held in 
December 1998. Announcement of this public meeting was published in the 
Federal Register on September, 29, 1998 (63 FR 51865).

Summary of This AD Action

    Several icing-related incidents and accidents of Mitsubishi MU-2B 
series airplanes caused FAA to investigate the airplane design and 
pilot's ability to operate in icing conditions. The FAA conducted a 
special certification review, which focused on factual information 
related to Mitsubishi MU-2B series airplanes involved in icing 
incidents/accidents. This review was named a Focused Fact Finding 
Special Certification Review (FFFSCR). This review shows that several 
accidents and incidents have occurred, and that modifications to the 
airplane design and additional pilot training may prevent future 
accidents/incidents. The training issues were addressed in AD 97-20-14, 
Amendment 39-10150 (62 FR 51594, October 2, 1997).
    The following presents whether FAA has included in or excluded from 
this final rule each action that was proposed in the NPRM:

------------------------------------------------------------------------
                                               Included in or  excluded
                Modification                           from AD
------------------------------------------------------------------------
Ice Detection System.......................  Excluded from AD.
Deice Monitoring System....................  Included in AD.
Automatic Autopilot Disconnect System and    Included in AD.
 Trim-in-motion Alert System.
Engine Continuous-duty Ignition Replacement  Excluded from AD.
 System.
Auto-ignition (Re-light System)............  Included in AD.
Placard to require negative torque sensing   Excluded from AD.
 (NTS) check and Propeller Feather Valve
 check as part of the Normal Checklist
 Procedures.
------------------------------------------------------------------------

    The following presents the actions we proposed in the NPRM, but are 
excluding from the final rule AD. Also included is a brief description 
of why we are excluding each one:
    1. Ice detection system: The Aviation Rulemaking Advisory Committee 
(ARAC) recently established an Ice Protection Harmonization Working 
Group (IPHWG). We are waiting for this group to conclude its study 
before deciding whether to require an ice detection system on the 
affected airplanes;
    2. Engine continuous-duty ignition system: We determined that the 
safety aspect of this AD only required the incorporation of the auto-
ignition (re-light) system or the engine continuous-duty ignition 
system. We chose the auto-ignition (re-light system) because it is 
independent of other pilot actions; and
    3. Placard to require negative torque sensing (NTS) check and 
propeller feather valve check as part of the Normal Checklist 
Procedures: We determined that the safety aspects of including this 
information did not outweigh the confusion that could be

[[Page 30867]]

generated through the installation of such a large placard on the 
instrument panel. If our analysis of the continued airworthiness of the 
affected airplanes shows that this information is necessary, we may 
initiate further rulemaking to require this information to become part 
of the Limitations Section of the Airplane Flight Manual (AFM).
    The FAA has determined that the modifications required in this AD 
will correct the unsafe condition identified in the NPRM. We considered 
all comments received.
    The following paragraphs present the comments received on the NPRM 
and at the public meeting. Also included is FAA's response to each 
comment, including any changes incorporated into the final rule based 
on the comments.

Comment Issue No. 1: Pilot Training

What Is the Commenters' Concern?

    Many commenters state that inadequate pilot training is the cause 
of the referenced incidents and accidents of the Mitsubishi MU-2B 
series airplanes.

What Is FAA's Response to the Concern?

    The FAA partially concurs. The FAA has determined that both systems 
modifications and pilot training are needed to prevent future icing 
accidents and incidents on the Mitsubishi MU-2B series airplanes. 
Training issues were addressed in AD 97-20-14, Amendment 39-10150 (62 
FR 51594, October 2, 1997). The FAA will continue to monitor the need 
for future training and will take any appropriate action. This AD 
addresses the systems modifications.
    We are not changing the AD as a result of these comments.

Comment Issue No. 2: Ice Detection System

What Are the Commenters' Concerns?

    Numerous commenters object to the incorporation of an ice detection 
system because:
    1. Pilot training is the issue and FAA should focus on providing 
the appropriate training.
    2. The ice detection system will not solve the problem because the 
Aerospatiale Model ATR-72 airplane involved in the Roselawn accident 
had an ice detection system installed and a problem still existed.
    3. The Roselawn accident with the Aerospatiale Model ATR-72 
airplane would not have occurred if the autopilot had remained 
connected; therefore, the problem with the Mitsubishi MU-2B series 
airplanes is the autopilot disconnect.
    4. The ice detection system is a bad idea because of the excellent 
visual icing cues of the MU-2B series airplanes and the potential for 
unrecognized mechanical failure.
    5. Based on a commenter's experience in another type of airplane, 
the ice detection system could provide false positive warnings.
    6. Install BF Goodrich Company SMART BOOTS on the affected 
airplanes. These boots incorporate electronic sensors imbedded into the 
surface of the vertical stabilizer deicing system; and detect the 
presence of ice on the surface of the boots, the proper functioning of 
the boots, and the presence of residual ice. The commenter believes 
that this system would allow FAA to learn more about the icing 
environment as it relates to the affected airplanes.
    7. An ice detection system is unnecessary because the pilot would 
use the visual cues to detect ice and could then activate the deicing 
system. This would make the need for an ice detection system 
unnecessary.
    8. Since the pilot is aware of the ice prior to the ice detection 
alert, the system is unnecessary, expensive, and a waste of money.

What Is FAA's Response to the Concerns?

    The Aviation Rulemaking Advisory Committee (ARAC) has established 
an Ice Protection Harmonization Working Group (IPHWG). One of the areas 
this group is currently studying is the safety impact of having ice 
protection systems incorporated on aircraft. Because this study is 
ongoing and the IPHWG has not made any recommendations, we have 
determined not to require the ice detection system in this AD. We will 
evaluate the information that the IPHWG provides at the conclusion of 
the study to determine whether we should initiate rulemaking regarding 
this subject. The Mitsubishi MU-2B series airplanes would be among many 
aircraft evaluated to determine whether an ice detection system should 
be incorporated. The AD requirements for the automatic autopilot 
disconnect system and trim-in-motion alert system provide protection in 
the event of undetected, dangerous ice accretions. We determined that 
the modifications required by this AD, including the automatic 
autopilot disconnect system and trim-in-motion alert system, will 
provide the operators the necessary warning and equipment to safely 
operate their airplanes.
    We excluded the ice detection system requirement from the AD.

Comment Issue No. 3: Stall Recovery

What Is the Commenter's Concern?

    One commenter questions why FAA did not give the option (as a 
method of accomplishing the AD) of advancing the power (engine torque) 
to as high as possible (i.e., in excess of 150 percent, which occurred 
in another type design airplane). This idea is based on the commenter's 
operating experience in recovering from a stall during an icing-related 
incident.

What Is FAA's Response to the Concern?

    We do not concur. When the engine torque is advanced over 100 
percent, the thrust of the propeller may be reduced because of the flow 
separation of portions of the blade. Instead of an increase in thrust, 
a reduction in overall thrust is likely. Airflow over the wing in the 
propwash can be degraded. FAA analysis of the incident that the 
commenter refers to shows that the airplane recovery occurred when the 
flaps were extended from the cruise configuration to 15 degrees and 
when the angle of attack was decreased. The flow over the wing 
returned, control of the airplane was regained, and the roll attitude 
stabilized.
    We are not changing the AD as a result of this comment.

Comment Issue No. 4: Misuse of the AD Process

What Are the Commenter's Concerns?

    One commenter states that (1) AD's are only for defects in design 
or potential equipment failures; and (2) proceeding with the AD would 
be a misuse of the AD process.

What Is FAA's Response to the Concerns?

    We do not concur. An AD is the vehicle that FAA uses to mandate 
modifications, inspections, etc., in order to correct an unsafe 
condition on products (airplanes). That condition could be caused by 
airplane usage (fatigue), quality control, design, maintenance problems 
(where the procedures to accomplish such maintenance are not available 
to the field or the current maintenance procedures are not meeting the 
necessary safety level), or any other problem. The FAA has determined 
that an unsafe condition exists in the Mitsubishi MU-2B series 
airplanes when utilized in icing conditions, and that the airplane 
modifications specified in the AD are necessary to correct this unsafe 
condition. We are not using this

[[Page 30868]]

AD to improve the level of safety or upgrade the certification level of 
the Mitsubishi MU-2B airplanes.
    We are not changing the AD as a result of these comments.

Comment Issue No. 5: Other Airplane Designs Are More Susceptible to 
Icing Problems Than the Mitusbishi MU-2B Series Airplanes

What Is the Commenters' Concern?

    Several commenters suggest that other airplane models (specifically 
Raytheon models) are more susceptible to problems while operating in 
icing conditions than the Mitsubishi MU-2B series airplanes. The 
commenters believe FAA should withdraw the NPRM for this reason.

What Is FAA's Response to the Concern?

    The FAA does not concur that the NPRM should be withdrawn because 
of the statement that other airplanes are more susceptible to problems 
while operating in icing conditions. The FAA analyzes the service 
history and design of each specific airplane make and model type design 
before taking AD action. Based on the service history and design of the 
Mitsubishi MU-2B series airplanes, FAA has determined that AD action is 
necessary. This does not mean that FAA will not take AD action on any 
other type design airplanes or that the Mitsubishi MU-2B series 
airplanes are being singled out from other type design airplanes. The 
FAA will continue to analyze the service history and design of each 
specific airplane make and model type design, and initiate and 
implement any appropriate rulemaking action.
    We are not changing the AD as a result of these comments.

Comment Issue No. 6: No Evidence That the Affected Airplanes Are 
Susceptible to Undetectable Ice Accumulation

What Is the Commenter's Concern?

    One commenter objects to the stated purpose and provisions 
specified in the NPRM. In particular, the commenter states that there 
is no evidence that the Mitsubishi MU-2B series airplanes are 
susceptible to undetectable ice accumulation.

What Is FAA's Response to the Concern?

    The FAA does not concur. In one reported incident of undetectable 
ice accumulation on one of the affected airplanes, a pilot in 14 CFR 
part 135 operations experienced a 20-knot decrease in airspeed and a 
change of positive climb rate to a descent. After examining the 
airplane surfaces, the crew saw no evidence of ice and instead only saw 
a shiny appearance on the leading edge of the wing. At this time, the 
crew operated the deicing boots and witnessed approximately 1-inch of 
ice shedding from the leading edge of the wing. Airplane performance 
was restored to the level that existed before the airplane entered the 
icing condition and before operation of the deicing boots. The bulk of 
the ice was on the surface of the boots and not the unprotected areas 
of the fuselage or the propellers. Transparent (clear) ice can result 
from high liquid water conditions, high airspeed, static air 
temperatures just below freezing, large droplets, or a combination of 
any of these conditions. The Mitsubishi MU-2B series airplanes have 
shown flight characteristics in icing conditions with clear ice 
formation that are hazardous. These hazards may be attributed to a 
decreased stall angle, suddenness and the degree of roll upset, a 
subsequent rapid increase in airspeed, the consequent loss of control 
after ice accumulation, and difficulty in recovering from any of the 
above problems. We determined that the modifications required by this 
AD, including the automatic autopilot disconnect system and trim-in-
motion alert system, will provide the operators the necessary warning 
and equipment to safely operate their airplanes.
    We are not changing the AD as a result of this comment.

Comment Issue No. 7: High Incident/Accident Rate for the Mitsubishi 
MU-2B Series Airplanes

What Is the Commenter's Concern?

    One commenter states that, of the 700 Mitsubishi MU-2B series 
airplanes in service, over 100 have been involved in incidents/
accidents.

What Is FAA's Response to the Concern?

    The FAA infers from this that the commenter agrees with and 
supports the AD.
    We are not changing the AD as a result of this comment.

Comment Issue No. 8: No AD Justification Based on the FFFSCR

What Is the Commenters' Concern?

    Several commenters state that, since the Mitsubishi MU-2B series 
airplanes ``passed all the tests'' in the FFFSCR, issuing an AD 
requiring modifications would be contrary to the FFRSCR. The commenters 
do not believe FAA should issue the AD because the airplane meets the 
appropriate certification regulations.

What Is FAA's Response to the Concern?

    We do not concur. The FFFSCR specifically addressed flight into 
icing conditions. The tests were not pass/fail situations. The FFFSCR 
specifies that several accidents have occurred, and that future 
accidents/incidents may be prevented by modifications to the airplane 
design and by additional training to enhance the pilot's ability to 
manage the airplane in adverse operating conditions.
    As discussed previously, an AD is the vehicle that FAA uses to 
correct unsafe conditions in type design products. A product that meets 
all certification requirements can still be found to have an unsafe 
condition that could exist or develop; also, an unsafe condition does 
not necessarily exist for products that do not meet certification 
requirements. Whether a product is in compliance with other regulations 
is unrelated to whether AD action should be taken on that product.
    We are not changing the AD as a result of these comments.

Comment Issue No. 9: Unsafe Condition Already Covered by Existing 
AD's

    What Is the Commenter's Concern?
    One commenter states that the unsafe condition referenced in this 
AD is already addressed by current AD's that apply to Mitsubishi MU-2B 
series airplanes:
    <bullet> One that requires training for the pilots of the affected 
airplanes;
    <bullet> One that requires incorporating a minimum speed 
limitation; and
    <bullet> One that addresses actions to take when flying into severe 
icing.
    For this reason, the commenter requests that FAA withdraw the NPRM.

What Is FAA's Response to the Concern?

    We do not concur. The current AD's that address severe icing and a 
minimum speed limitation contain information that applies to many type 
design airplanes, not just the Mitsubishi MU-2B series airplanes. Pilot 
training and system modifications are specific to the type design of 
the Mitsubishi MU-2B series airplanes. The FFFSCR specifies that 
several accidents have occurred, and that future accidents/incidents 
may be prevented by modifications to the airplane design and by 
additional training to enhance the pilot's ability to manage the 
airplane in adverse operating conditions. We have determined that both 
systems modifications and pilot training are needed to prevent future 
icing incidents on the Mitsubishi MU-2B series airplanes. Training 
issues were addressed in AD 97-20-14, Amendment 39-10150 (62 FR 51594, 
October 2, 1997). The FAA will continue to monitor the need for future 
training and

[[Page 30869]]

will take appropriate action. This AD addresses the systems 
modifications.
    We are not changing the AD as a result of this comment.

Comment Issue No. 10: Trim-in-Motion

What Is the Commenters' Concern?

    Several commenters oppose the incorporation of a trim-in-motion 
system. The commenters state that the trim-in-motion system will 
annunciate during normal trim activation and the pilot will hear the 
trim-in-motion alert continuously and ``tune it out.'' The commenters 
would like FAA to eliminate the trim-in-motion system requirement.

What Is FAA's Response to the Concern?

    We do not concur. The trim-in-motion system for the MU-2B series 
airplanes annunciates only after the trim wheel has rotated more than 
30 degrees in the nose-up direction when the flaps are retracted. This 
should eliminate ``nuisance alerts''.
    We are not changing the AD as a result of these comments.

Comment No. 11: Automatic Autopilot Disconnect

What Are the Commenters' Concerns?

    Several commenters oppose the incorporation of an automatic 
autopilot disconnect. The commenters express the following concerns:
    1. The automatic autopilot disconnect is dangerous in that the 
autopilot could become disconnected in high workload conditions.
    2. The Mitsubishi MU-2B series airplane is a one-pilot airplane and 
the autopilot provides a useful function as a workload reliever.
    3. The automatic autopilot disconnect is unnecessary because no 
accidents have occurred since the AD was issued that required a minimum 
180 knot indicated airspeed (KIAS). The commenters would like FAA to 
eliminate the automatic autopilot disconnect requirement.
    4. The autopilot would disconnect at a speed slightly faster than 
the best rate of climb speed for certain weight and altitude 
combinations. The commenters state that icing rarely occurs above 
25,000 feet. This is the desired altitude in certain weather conditions 
where the slowest airspeeds are required for the best rate of climb. 
The commenters believe that a hazardous situation would exist if the 
pilot were to hand fly the airplane to achieve the best rate of climb 
instead of utilizing the autopilot.

What Are FAA's Responses to the Concerns?

    The following presents FAA's response to each of the concerns 
regarding the automatic autopilot disconnect:
    1. We concur that high workload conditions exist. However, the 
objective of the automatic autopilot disconnect is to prevent the 
autopilot from applying nose-up elevator control with pitch trim until 
the airplane stalls. When implemented, the pilot will be forced to take 
control of the airplane before the autopilot applies pitch control in 
the full trimmed nose-up direction. If the autopilot controls the 
airplane into a stall, then the chance of a recovery is unlikely. The 
automatic autopilot disconnect would, prior to a stall condition, give 
control to the pilot and allow detection and prevention of a stall. The 
automatic autopilot disconnects well below the cruise speed and just 
above the stall speed.
    2. We concur that the Mitsubishi MU-2B series airplane is a single-
pilot airplane and the autopilot provides a useful function as a 
workload reliever. The airplane was certificated without the autopilot 
and is considered optional equipment. Any pilot of this aircraft should 
be able to handle situations without the use of the autopilot the same 
as with the autopilot. As discussed above, the automatic disconnect 
function activates at a speed that provides increased margin to 
contaminated stall. This places the pilot in situations where the 
continued reliance on the autopilot may mask natural stall warnings 
prior to stall and upset.
    3. We do not concur with the commenter that no accidents have 
occurred since the AD was issued to require a minimum 180 KIAS in icing 
conditions, and therefore the automatic autopilot disconnect is 
unnecessary. Since 1993 when the 180 KIAS minimum speed was 
established, an airplane upset occurred in an accident in Malad City, 
Utah. Speeds were lower than 180 KIAS.
    4. We do not concur that a hazardous situation would exist if the 
pilot would hand fly the airplane at altitudes above 25,000 feet. 
Cumulonimbus clouds account for the icing above 25,000 feet. These 
clouds contain some of the most severe forms of icing conditions. Icing 
accrued at lower altitudes may easily remain on the airfoil and then 
the airplane could carry this ice to higher altitudes. As discussed 
earlier, these airplanes were certificated without the autopilot and 
the autopilot is considered optional equipment. Any pilot of this 
aircraft should be able to handle situations without the use of the 
autopilot the same as with the autopilot.
    We are not changing the AD as a result of these comments.

Comment Issue No. 12: Require Either an Auto-ignition (Re-light) 
System or an Engine Continuous-Duty Ignition Replacement System

What Is the Commenters' Concern?

    The commenters believe that requiring either the engine continuous-
duty ignition replacement system or the auto-ignition (re-light) system 
is acceptable. The commenters state that requiring both is redundant 
and FAA has not provided justification for requiring both.

What Is FAA's Response to the Concern?

    We concur that both of these systems should not be required. Based 
upon the operating record of other airplanes equipped with the auto-
ignition (re-light) system, FAA believes that this system is the best 
for restoring engine power because:
    <bullet> Manual selection of the ignition after ice detection 
depends on the pilot seeing the ice and knowing when the airplane is no 
longer in a condition conducive to flameout; and
    <bullet> Use of the engine continuous-duty ignition replacement 
system for extended periods of time incurs repetitive igniter 
replacement costs. The use of the auto-ignition (re-light) system is 
independent of pilot ice detection. This system is also energized for a 
short period of time so it incurs less operating cost.
    We excluded the requirement of incorporating an engine continuous-
duty ignition replacement system.

Comment Issue No. 13: Experienced MU-2B Series Airplanes Operators 
Were Not Contacted

What Is the Commenters' Concern?

    Several commenters question why FAA never contacted ``experienced'' 
MU-2B series airplane operators.

What Is FAA's Response to the Concern?

    We contacted several MU-2B series airplane operators to seek 
information on possible upsets or near upsets in icing conditions. 
Among these were pilots in 14 CFR part 91 and part 135 operations.
    We are not changing the AD as a result of these comments.

[[Page 30870]]

Comment Issue No. 14: Specific Accidents Are Unrelated to This AD

What Are the Commenters' Concerns?

    Several commenters believe that most of the MU-2B series airplane 
accidents are unrelated to the subject matter of this AD. The 
commenters state that FAA should not take AD action because the 
accidents were related to pilot error or judgement. Some of the 
commenters state that, when you take the pilot error or judgement 
issues away, there are not enough accidents to warrant AD action.

What Is FAA's Response to the Concerns?

    We do not concur. We determined that human error has not accounted 
for all accidents and incidents involving MU-2B series airplanes. The 
type and severity of the icing conditions in these accidents has 
resulted in fatalities to the occupants of these MU-2B series 
airplanes. This is because they were in uncontrolled flight into 
terrain from altitudes of 16,000 feet to 22,000 feet. Accidents are not 
a prerequisite for issuing an AD. The only prerequisite is an unsafe 
condition that is likely to exist or develop in other airplanes of the 
same type design.
    We are not changing the AD as a result of these comments.

Comment Issue No. 15: Operation Outside the Design Envelope

What Is the Commenter's Concern?

    One commenter states that the AD is not justified because the 
pilots of the Mitsubishi MU-2B series airplanes are flying outside the 
design limits of the airplane.

What Is FAA's Response to the Concern?

    We do not concur. The FAA does not have evidence of the affected 
airplanes being flown outside of the design limits up to the moment of 
loss of control.
    We are not changing the AD as a result of this comment.

Comment Issue No. 16: The MU-2B Passed All Tests

What Are the Commenters' Concerns?

    One commenter states that AD action is unnecessary because the MU-
2B series airplanes passed all the tests during the FFFSCR. Another 
commenter states that the MU-2B airplanes passed all the tests during 
the special certification review (SCR) that FAA performed in 1984.

What Is FAA's Response to the Concerns?

    We do not concur. The purpose of the 1984 SCR was for the overall 
aspects of the airplane, and was not specific to icing-related 
problems. The 1996 FFFSCR specifically addressed flight into icing 
conditions. The tests during this FFFSCR were not pass/fail situations. 
The final report of the FFFSCR includes all the findings and 
conclusions and makes 14 different recommendations, including equipment 
and training recommendations.
    We are not changing the AD as a result of these comments.

Comment Issue No. 17: Power is the Key to Exiting Icing Conditions

What Is the Commenter's Concern?

    One commenter states that the one key to exiting icing conditions 
is power. The commenter requests that FAA focus on increasing power 
instead of system modifications.

What Is FAA's Response to the Concern?

    We do not concur. While power is a key when a pilot immediately 
exits icing conditions, airfoil lift and stall aerodynamics are most 
significant in icing conditions. The significant aerodynamic 
characteristics for the MU-2B series airplanes are the stall angle of 
attack and lift coefficient with ice accretion. These could lead to 
increased drag, which may result in an insufficient amount of engine 
power (thrust) available to exit the icing conditions. The level of 
thrust necessary to overcome all icing conditions could be more than 
the MU-2B series airplanes can provide. Nominal changes in propeller 
effectiveness with ice accretion decrease propeller performance.
    We are not changing the AD as a result of this comment.

Comment Issue No. 18: Similar Action Necessary for Other Aircraft

What Is the Commenter's Concern?

    One commenter states that the icing accident statistics of other 
airplanes are higher than the Mitsubishi MU-2B series airplanes. The 
commenter specifically calls out the statistics for the Cessna Model 
421 airplanes. Another commenter states that FAA should require similar 
actions on the Commander Model 114 airplanes.

What Is FAA's Response to the Concern?

    The Cessna Model 421 airplanes and the Commander Model 114 
airplanes are a different type design to that of the Mitsubishi MU-2B 
series airplanes. The FAA looks at the service history and design of 
each particular aircraft to determine whether an unsafe condition 
exists or is likely to develop, and AD action is necessary. The FAA 
will issue an AD if it determines that similar action needs to be taken 
on any other type design aircraft.
    We are not changing the AD as a result of these comments.

Comment Issue No. 19: MU-2B Attracts Financially Weak Operators

What Is the Commenter's Concern?

    One commenter states that the MU-2B series airplanes attract 
operators who do not have the financial strength to properly maintain 
their aircraft and train their crews. The commenter indicates that this 
is due to the affected airplanes being market bargains because of 
factors such as the issuance of the NPRM and the mandatory training AD 
against the MU-2B series airplanes. The FAA infers that the commenter 
believes the AD is only necessary to those operators without proper 
financial resources.

What Is FAA's Response to the Commenter's Concern?

    The FAA does not concur. The unsafe condition exists when the 
airplane is flying in icing conditions. The FAA initiates AD action 
based only on whether an unsafe condition exists or could develop on 
type design aircraft. The market value of the affected airplanes or the 
financial status of the owners/operators of those airplanes does not 
enter into FAA's decision.
    We are not changing the AD as a result of this comment.

Comment Issue No. 20: Severity of Ice Testing

What Is the Commenters' Concern?

    Several commenters question the severity of the icing problems 
found during the tanker testing conducted with the FFFSCR. The 
commenters state that the AD is not necessary because they believe this 
testing is the primary justification for the AD.

What Is FAA's Response to the Concern?

    We do not concur. The tanker testing was intended to examine only 
the ice accretion aft of the active portion of the deicing boots. This 
was where the ice accretion was found on the ATR airplane in the 
Roselawn accident. During this testing, only small portions of the 
airplane were exposed to the icing cloud at any particular time because 
the icing effect could not be accomplished simultaneously on all 
airplane surfaces located behind the tanker.
    The entire natural icing environment cannot be replicated using 
computational fluid dynamics (CFD). This environment also cannot be 
sampled during flight testing in natural

[[Page 30871]]

icing conditions. Each condition is unique and variable. If you then 
account for airplane design, the chances for developing the most severe 
ice shape for any one aerodynamic characteristic is difficult.
    This information reveals that neither the testing nor other tools 
are able to address all possible hazardous conditions on the Mitsubishi 
MU-2B series airplanes. The FAA has determined that the systems 
modifications required by this AD will give the pilot the best chance 
of maintaining control of the airplane in icing conditions.
    We are not changing the AD as a result of these comments.

Comment Issue No. 21: Congressional Pressure

What Is the Commenters' Concern?

    Several commenters believe that FAA yielded to congressional 
pressures in conducting the FFFSCR and issuing the NPRM. These 
commenters state that the FFFSCR was precipitated by a letter from a 
U.S. congressman relating to an accident in Zwingle, Iowa. The MU-2B 
series airplane in this accident experienced an uncontained propeller 
blade failure and then struck a silo. The commenters believe the AD is 
unnecessary and FAA is taking action because of politics.

What Is FAA's Response to the Concern?

    Although it was part of the information we reviewed when deciding 
to conduct the FFFSCR, the congressional letter was not the determining 
factor. The FAA was already analyzing the service history of the 
Mitsubishi MU-2B series airplanes. The decision to issue the NPRM was 
based on:
    <bullet> The conclusions made from the FFFSCR;
    <bullet> The review of the affected airplanes' service history; and 
-
    <bullet> The testing and approval of the system modifications 
included in the NPRM.
    Our analysis of the situation does not link the Iowa accident 
referenced in the congressman's letter to the icing problems of the MU-
2B series airplanes.
    We are not changing the AD as a result of these comments.

Comment Issue No. 22: AD is an Economic Burden

What Are the Commenters' Concerns?

    Several commenters addresss the economic impact caused by this AD 
and recent AD's against the MU-2B airplanes, including:
    1. The AD's are senseless and have gone beyond reason;
    2. The apparent bending of the regulatory rules against the MU-2B 
series airplanes has resulted in higher insurance premiums, higher 
parts costs, and decreased aircraft values; and
    3. The NPRM, if adopted as a final rule, will cost each owner/
operator about $27,000.

What Are FAA's Responses to the Concerns?

    Our response to each concern follows:
    1. We do not concur. The FAA presumes that the commenters are 
referring to the NPRM and other AD's written against the MU-2B series 
airplanes. Each AD, including the NPRM, must be justified through the 
identification of an unsafe condition. The FAA followed all regulatory 
processes for the AD's, including the NPRM, against the affected 
airplanes;
    2. The FAA does not concur. As stated above, FAA followed all 
regulatory processes for the AD's, including the NPRM, against the 
affected airplanes; and
    3. The FAA concurs that the NPRM as written would cost 
approximately $27,000 per airplane. The final rule will actually cost 
less than that proposed in the NPRM since the requirement for the ice 
detection system modification and the engine continuous-duty ignition 
replacement system modification are excluded. The FAA completed a 
Regulatory Flexibility Analysis on the NPRM. This analysis included the 
above modifications. The FAA has determined that the safety problems 
that would exist if this AD was not required outweigh the negative cost 
impact of this AD upon the public.
    We Are not changing the AD as a result of these comments.

Comment Issue No. 23: Product Improvement Modifications

What Are the Commenters' Concerns?

    Several commenters state that the installations specified in the 
NPRM are product improvements and do not address a true unsafe 
condition. The commenters indicate that Mitsubishi developed the 
modifications and issued the service bulletins before the FFFSCR.
    Another commenter believes that FAA will use this AD as an example 
in mandating other product improvements in equipment such as global 
positioning systems (GPS) and stormscopes.

What Is FAA's Response to the Concerns?

    We concur that a few of the modifications were developed prior to 
the FFFSCR. Since FAA had not mandated these modifications through an 
AD, they could have been considered product improvements at that time. 
Since that time, FAA performed the FFFSCR; determined that an unsafe 
condition exists and an AD should be issued; and analyzed the 
modifications that Mitsubishi developed. Part of addressing the unsafe 
condition is incorporating the modifications that were developed prior 
to the FFFSCR. The FAA can only mandate modifications that exist 
through an AD. An unsafe condition must be demonstrated for any AD 
action.
    We are not changing the AD as a result of these comments.

Comment Issue No. 24: Require a Type Rating and Copilot for Certain 
Operations

What Are the Commenter's Concerns?

    One commenter states that the following should be required when 
operating MU-2B series airplanes under 14 CFR part 135:
    1. The pilot-in-charge should have a type rating; and
    2. All Mitsubishi MU-2B series airplanes should have a copilot.

What Are FAA's Responses to the Concerns?

    We do not concur with these concerns for the following reasons:
    1. During the special certification review performed in 1984, FAA 
determined that a type rating was not necessary. Nothing has changed to 
warrant the need for a type rating.
    2. Mandating a copilot in 14 CFR part 135 operations is beyond the 
scope of AD action. The FAA would need to make a rulemaking change to 
the specific regulation.
    We are not changing the AD as a result of these comments.

Comment Issue No. 25: Delete the Requirement for Installing a 
Placard on the Instrument Panel

What Is the Commenters' Concern?

    Several commenters request that the FAA delete the requirement to 
install a placard to require a negative torque sensing (NTS) check and 
propeller feather valve check as part of the Normal Checklist 
Procedures. The commenters state that confusion could be generated 
through the installation of such a large placard on the instrument 
panel.

What Is FAA's Response to the Concern?

    We concur that a placard is not the best way of accomplishing this 
action. These checks are currently part of the

[[Page 30872]]

Normal Checklist Procedures Section of the AFM. The FAA encourages 
accomplishment of all actions specified in this section. However, the 
only mandatory actions in the AFM are those included in the Limitations 
Section.
    Mandating these checks as part of an addition to the Limitations 
Section of the AFM would impose actions that go beyond the scope of 
what was already proposed in the NPRM. If our analysis of the continued 
airworthiness of the affected airplanes shows that it is necessary to 
mandate these actions, we may initiate further rulemaking to require 
this information to become part of the Limitations Section of the AFM.
    We excluded the placard requirement from the AD.

The FAA's Determination

What Is FAA's Final Determination on This Issue?

    After reviewing all available information related to the subject 
presented above, we have determined that air safety and the public 
interest require the adoption of the rule as proposed except for the 
changes described above and minor editorial corrections.

How Do These Changes and Corrections Affect the AD?

    We have determined that the addition and minor corrections will not 
change the meaning of the AD and will not add any additional burden 
upon the public than was already proposed.

Compliance Time of This AD

What Is the Compliance Time of This AD?

    The compliance time of this AD is within the next 12 calendar 
months after the effective date.

Why Is the Compliance in Calendar Time Instead of Hours Time-in-
Service?

    We have determined that the compliance time of this AD should be 
specified in calendar time instead of hours time-in-service. Although 
the condition addressed by this AD is unsafe while the airplane is in 
flight, the condition is not a result of repetitive airplane operation. 
The potential for the unsafe condition occurring is the same on the 
first flight as it is for subsequent flights. The compliance time of 
``12 calendar months after the effective date of this AD'' will not 
inadvertently ground airplanes and will assure that all owners/
operators of the affected airplanes accomplish this action in a 
reasonable time period.

Regulatory Flexibility Determination and Analysis

    The Regulatory Flexibility Act of 1980 was enacted by Congress to 
assure that small entities are not unnecessarily or disproportionately 
burdened by government regulations. This Act establishes ``as principle 
of regulatory issuance that agencies shall endeavor, consistent with 
the objectives of the rule and of applicable statutes, to fit 
regulatory and informational requirements to the scale of the 
businesses, organizations, and governmental jurisdictions subject to 
regulation.'' To achieve this principle, the Act requires agencies to 
solicit and consider flexible regulatory proposals and to explain the 
rationale for their actions. The Act covers a wide range of small 
entities, including small businesses, not-for-profit organizations, and 
small governmental jurisdictions.
    Agencies must perform a review to determine whether a rule will 
have a ``significant economic impact on a substantial number of small 
entities.'' If the determination is that it will, the agency must 
prepare a Regulatory Flexibility Analysis as described in the Act. 
However, if after a review for a proposed or final rule, an agency 
determines that a rule is not expected to have a significant economic 
impact on a substantial number of small entities, section 605(b) of the 
Act provides that the head of the agency may so certify and a 
Regulatory Flexibility Analysis is not required. A statement providing 
the factual basis for this determination must be included in the Docket 
file, and the reasoning should be clear.
    The FAA has determined that this AD will have a significant 
economic impact on a substantial number of small entities. After a 
review of alternatives, as required by section 603(c) of the Act, this 
AD is the least costly alternative to reduce the possibility of an 
unsafe condition on Mitsubishi MU-2B series airplanes when operating in 
icing conditions.
    The entities affected by this AD are believed to be mostly in 
Standard Industrial Classification (SIC) 4522, ``Air Transportation, 
Nonscheduled.'' Under the Small Business Administration (SBA), Table of 
Size Standards, March 1, 1996, an entity in SIC 4522 would be a small 
business if it has fewer than 1,500 employees.
    The U.S. Registered Aircraft Database shows approximately 200 
operators of Mitsubishi MU-2B series airplanes in the United States, 
but that only 13 entities operate 2 or more of these airplanes. 
Ownership of more than 1 MU-2B series airplane is believed to be 
limited to 5 percent of the affected aircraft owners. Only one of these 
operators had 10 or more of these airplanes. The total number of owners 
operating MU-2B series airplanes is in the range of 320 to 340, and the 
names of the owners suggest that the majority of these airplanes are 
operated by small entities. Consequently, this AD is likely to affect a 
substantial number of small entities.
    The initial cost for each owner/operator of an MU-2B series 
airplane is estimated to be approximately $25,728. Reported usage rates 
of 32 to 33 hours per month (almost 400 hours per year) indicate that 
an airplane will be subject to a total of four inspections per year. At 
a nominal inspection time of 1 workhour per inspection and labor cost 
of $60 per workhour, the annual inspection costs will be approximately 
$240 per airplane. These estimates include costs for the associated 
record keeping. A reasonable range of costs arising from this AD is 
suggested in the following table:

----------------------------------------------------------------------------------------------------------------
                                                  Remaining life          Annualized cost
                 Cost of capital                    of aircraft  --------------------------------  Present value
                                                    (in years)        Initial          Total       of total cost
----------------------------------------------------------------------------------------------------------------
10%/year........................................              20          $3,022          $3,262         $27,771
15%/year........................................              20           4,110           4,350          27,230
10%/year........................................              10           4,187           4,427          27,203
15%/year........................................              10           5,126           5,366          26,933
----------------------------------------------------------------------------------------------------------------

    The remaining life for an affected airplane will depend on the 
demand for the types of service provided (such as cargo delivery and 
medical evacuation), as well as the difference in cost between 
providing this service with the MU-2B series airplanes and the cost of 
using alternative aircraft or modes of transportation. According to the

[[Page 30873]]

manufacturer, detailed inspections show that deterioration of the 
airframes has been quite small, so that a 20-year life expectancy may 
be a reasonable presumption. In addition, the manufacturer acknowledged 
recent instances of retired MU-2B series airplanes being returned to 
service. These considerations suggest that it is reasonable to presume 
a relatively long expected life for many of the MU-2B series airplanes, 
so that the annualized cost per affected aircraft may average less than 
$5,000.
    With an average annual cost per airplane in the range of $3,200 to 
$5,400 (consistent with 10 to 20 years of remaining life and capital 
costs of 10 to 15 percent per year), the present value of the total 
cost will be approximately $27,000 per airplane. The total annualized 
cost of this AD for the U.S. fleet will be in the range of $1 million 
(320  x  $3,200 = $1,024,000) to $1.8 million (340  x  $5,400 = 
$1,836,000). The present discounted value of total costs imposed by 
this AD are in the range of $8.6 million to $9.4 million. Market values 
for the affected airplanes are believed to be in the range of $300,000 
to $800,000, depending on the airplane's age, condition, and installed 
equipment. Therefore, the AD costs will be about 3.5 percent to 9 
percent (($27,000 / $800,000)  x  100% = 3.5% to ($27,000 / $300,000) 
x  100% = 9%) of the market value of the airplane. Because the costs 
imposed by this AD will be proportionately higher for less expensive 
airplanes, it is likely that they will also be proportionately higher 
for smaller, less financially strong operators than for larger 
operators.
    In developing the Regulatory Flexibility Analysis, several 
alternatives to this AD were considered. The alternatives included:

Option No. 1

    Take no action, including not issuing this AD.
    The FAA's Position on Option No. 1: Taking no action will permit 
the continuation of current conditions that could result in a repeat of 
icing-related accidents similar to those that have occurred over the 
past 10 years.

Option No. 2

    Require additional training.
    The FAA's Position on Option No. 2: The FAA addressed the training 
issue in AD 97-20-14, Amendment 39-39-10150 (62 FR 51594). This AD 
requires periodic training for the pilots and crew flying any 
Mitsubishi MU-2 series airplane. The training provides information 
relative to flight into possible or forecast icing conditions. This 
training should assist in reducing future ice-related accidents for the 
affected airplanes.

Option No. 3

    Issue AD action to restrict the MU-2B series airplanes operators 
from flight into known or suspected icing conditions.
    The FAA's Position on Option No. 3: The FAA has determined that 
restricting flight into known or suspected icing conditions will not 
eliminate inadvertent encounters with icing conditions. Such 
restrictions may have little effect on flying into unforecast icing 
conditions with inoperable anti-ice equipment and insufficient flight 
planning. Unknown forecast conditions and insufficient flight planning 
contributed to two of the accidents (and 13 of the 14 fatalities) 
cited. In addition, such a restriction will impose costs on owners/
operators because the airplanes will be prevented from making flights, 
despite being outfitted with anti-ice equipment.

Option No. 4

    Require the actions in this AD.
    The FAA's Position on Option No. 4: The FAA has determined that 
requiring the modifications in this AD will help prevent undetected 
failure conditions and provide a timely warning prior to upset. This 
warning will enable the pilot to manually control the airplane before 
an unsafe condition develops.
    The FAA has determined that this AD is likely to have benefits in 
excess of costs and is not aware of a less costly alternative that will 
be likely to address the unsafe condition addressed in this AD.
    A copy of the complete Regulatory Flexibility Analysis may be 
obtained from FAA, Central Region, Office of the Regional Counsel, 901 
Locust, Room 506, Kansas City, Missouri .

Regulatory Impact

    The regulations adopted herein will 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. Therefore, FAA 
determines that this final rule does not have federalism implications 
under Executive Order 13132.
    The FAA has determined 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) Could have a significant economic impact on a substantial 
number of small entities under the criteria of the Regulatory 
Flexibility Act. We have placed a copy of the draft regulatory 
evaluation prepared for this action in the Rules Docket. You may obtain 
a copy of it at 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, under 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. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. FAA amends Sec. 39.13 by adding a new airworthiness directive 
(AD) to read as follows:

2000-09-15  Mitsubishi Heavy Industries, LTD.: Amendment 39-11724; 
Docket No. 97-CE-21-AD.

    (a) What airplanes are affected by this AD? This AD applies to 
all serial numbers of the following Mitsubishi airplane models, 
certificated in any category:

MU-2B
MU-2B-10
MU-2B-15
MU-2B-20
MU-2B-25
MU-2B-26
MU-2B-26A
MU-2B-30
MU-2B-35
MU-2B-36
MU-2B-36A
MU-2B-40
MU-2B-60

    (b) Who must comply with this AD? Anyone who wishes to operate 
any of the above airplanes on the U.S. Register must comply with 
this AD.
    (c) What problem does this AD address? The actions specified by 
this AD are intended to assist in preventing departure from 
controlled flight while operating in icing conditions.
    (d) What actions must I accomplish to address this problem? 
Within the next 12 calendar months after July 24, 2000 (the 
effective date of this AD), you must incorporate the following 
modifications:
    (1) Install a pneumatic deice monitoring system. You must use 
the procedures contained in Test Instrumentation, Inc. Document No. 
MU2-5001, Rev. E., dated

[[Page 30874]]

May 21, 1997; and Mitsubishi MU-2 Service Bulletin (SB) No. 232, 
dated July 2, 1997.
    (2) Install a trim-in-motion alerting system and automatic 
autopilot disconnect system. Use the procedures contained in Test 
Instrumentation, Inc. Document No. MU2-1001, Rev. C, dated June 15, 
1997; Test Instrumentation, Inc. Document No. MU2-4001, Rev. C, 
dated June 30, 1997; and Mitsubishi MU-2 SB No. 231, dated July 2, 
1997.
    (3) Install an auto-ignition (re-light) system. Use the 
procedures contained in Mitsubishi MU-2 SB No. 226, which 
incorporates the following pages:

------------------------------------------------------------------------
                                       Revision
                Pages                    level             Date
------------------------------------------------------------------------
2 through 11, 13 through 23, 27              A   January 13, 1997.
 through 57, and 59 through 93.
1, 12, 24, 25, 26, and 58............        B   October 27, 1997.
------------------------------------------------------------------------

    (e) Can I comply with this AD in any other way?
    (1) You may use an alternative method of compliance or adjust 
the compliance time if:
    (i) Your alternative method of compliance provides an equivalent 
level of safety; and
    (ii) The Manager of one of the following approves your 
alternative. Submit your request through an FAA Principal 
Maintenance Inspector, who may add comments and then send it to the 
Manager.
    (A) Los Angeles Aircraft Certification Office, FAA, 3960 
Paramount Blvd., Lakewood, California 90712; or
    (B) Fort Worth Airplane Certification Office, FAA, 2601 Meacham 
Boulevard, Fort Worth, Texas 76193-0150.
    (2) 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 (e)(1) 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 you have not eliminated the unsafe 
condition, specific actions you propose to address it.
    (f) Where can I get information about any already-approved 
alternative methods of compliance? Contact one of the following:
    (1) Small Airplane Directorate, FAA, 901 Locust, Room 301, 
Kansas City, Missouri 64106; telephone: (816) 329-4121; facsimile: 
(816) 426-4090;
    (2) Los Angeles Aircraft Certification Office, FAA, 3960 
Paramount Blvd., Lakewood, California 90712; telephone: (562) 627-
5222; facsimile: (562) 627-5228; or
    (3) Fort Worth Airplane Certification Office, FAA, 2601 Meacham 
Boulevard, Fort Worth, Texas 76193-0150; telephone: (817) 222-5147; 
facsimile: (817) 222-5960.
    (g) What if I need to fly the airplane to another location to 
comply with this AD? The FAA can issue a special flight permit under 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate your airplane to a location where 
you can accomplish the requirements of this AD.
    (h) Are any service bulletins incorporated into this AD by 
reference?
    (1) You must accomplish the actions required by this AD in 
accordance with the following:
    (i) Mitsubishi MU-2 SB No. 226, which incorporates the following 
pages:

------------------------------------------------------------------------
                                       Revision
                Pages                    level             Date
------------------------------------------------------------------------
2 through 11, 13 through 23, 27              A   January 13, 1997.
 through 57, and 59 through 93.
1, 12, 24, 25, 26, and 58............        B   October 27, 1997.
------------------------------------------------------------------------

    (ii) Mitsubishi MU-2 SB No. 231, dated July 2, 1997;
    (iii) Mitsubishi MU-2 SB No. 232, dated July 2, 1997;
    (iv) Test Instrumentation, Inc. Document No. MU2-1001, Rev. C, 
dated June 15, 1997, and attachments;
    (v) Test Instrumentation, Inc. Document No. MU2-4001, Rev. C, 
dated June 30, 1997, and attachments; and
    (vi) Test Instrumentation, Inc. Document No. MU2-5001, Rev. E., 
dated May 21, 1997, and attachments.
    (2) The Director of the Federal Register approved this 
incorporation by reference under 5 U.S.C. 552(a) and 1 CFR part 51.
    (3) You can get copies from Mitsubishi Heavy Industries America, 
Inc., 15303 Dallas Parkway, suite 685, LB-77, Dallas, Texas. You can 
look at copies at FAA, Central Region, Office of the Regional 
Counsel, 901 Locust, Room 506, Kansas City, Missouri, or at the 
Office of the Federal Register, 800 North Capitol Street, NW, suite 
700, Washington, DC.
    (i) When does this amendment become effective? This amendment 
becomes effective on July 24, 2000.

    Issued in Kansas City, Missouri, on May 5, 2000.
Michael Gallagher,
Manager, Small Airplane Directorate, Aircraft Certification Service.
[FR Doc. 00-11863 Filed 5-12-00; 8:45 am]
BILLING CODE 4910-13-U