27872 Federal Register / Vol. 63, No. 98 /Thursday, May 21, 1998 / Proposed Rules

accordance with paragraph 2 of the

Instructions section of DG Flugzeugbau

Technical Note No. 826/32, dated July 19,

1996, and WORKING INSTRUCTION No. 1

for TN 826/32, dated July, 1996.

(b) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the glider to a

location where the requirements of this AD

can be accomplished.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an equivalent level of safety may be

approved by the Manager, Small Airplane

Directorate, FAA, 1201 Walnut, suite 900,

Kansas City, Missouri 64106. The request

shall be forwarded through an appropriate

FAA Maintenance Inspector, who may add

comments and then send it to the Manager,

Small Airplane Directorate.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Small Airplane

Directorate.

(d) Questions or technical information

related to DG Flugzeugbau Technical Note

No. 826/32, dated July 19, 1996, and DG

Flugzeugbau WORKING INSTRUCTION No.

1 for TN 826/32, dated July, 1996, should be

directed to DG Flugzeugbau GmbH, P.O. Box

4120, 76625 Bruchsal, Germany; telephone:

+49 7257–89–0; facsimile: +49 7257–8922.

This service information may be examined at

the FAA, Central Region, Office of the

Regional Counsel, Room 1558, 601 E. 12th

Street, Kansas City, Missouri 64106.

Note 3: The subject of this AD is addressed

in German AD 96–243 DG–Flugzeugbau,

dated August 29, 1996.

Issued in Kansas City, Missouri, on May

13, 1998.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft

Certification Service.

[FR Doc. 98–13518 Filed 5–20–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–CE–21–AD]

RIN 2120–AA64

Airworthiness Directives; Mitsubishi

Heavy Industries, Ltd. Models MU–2B

Series Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Notice of proposed rulemaking

(NPRM).

SUMMARY: This document proposes to

adopt a new airworthiness directive

(AD) that would apply to certain

Mitsubishi Heavy Industries, Ltd.

(Mitsubishi) MU–2B series airplanes.

The proposed action would require

incorporating several modifications to

the operating systems and installing a

placard with operating limitations

within the pilot’s clear view. Service

history of the affected airplanes

prompted the FAA to examine the

design of these airplanes and analyze

the ability of the pilots of these

airplanes to fly and operate in icing

conditions. The actions specified by the

proposed AD are intended to prevent

departure from controlled flight and to

assist the pilot in detecting ice

accumulation on the airplane when

flying in icing conditions that exceed

the airplane’s ice protection capability,

which could result in possible loss of

control of the airplane.

DATES: Comments must be received on

or before July 22, 1998.

ADDRESSES: Submit comments in

triplicate to the Federal Aviation

Administration (FAA), Central Region,

Office of the Regional Counsel,

Attention: Rules Docket No. 97–CE–21–

AD, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106. Comments

may be inspected at this location

between 8 a.m. and 4 p.m., Monday

through Friday, holidays excepted.

Service information that applies to the

proposed AD may be obtained from

Mitsubishi Heavy Industries America,

Inc., 15303 Dallas Parkway, suite 685,

LB–77, Dallas, Texas 75248; telephone

(972) 980–5001; facsimile (972) 980–

5091. This information also may be

examined at the Rules Docket at the

address above.

FOR FURTHER INFORMATION CONTACT: Mr.

John Dow, Aerospace Engineer, Small

Airplane Directorate, 1201 Walnut, suite

900, Kansas City, Missouri 64106,

telephone (816) 426–6934; facsimile

(816) 426–2169.

SUPPLEMENTARY INFORMATION:

Comments Invited

Interested persons are invited to

participate in the making of the

proposed rule by submitting such

written data, views, or arguments as

they may desire. Communications

should identify the Rules Docket

number and be submitted in triplicate to

the address specified above. All

communications received on or before

the closing date for comments, specified

above, will be considered before taking

action on the proposed rule. The

proposals contained in this notice may

be changed in light of the comments

received.

Comments are specifically invited on

the overall regulatory, economic,

environmental, and energy aspects of

the proposed rule. All comments

submitted will be available, both before

and after the closing date for comments,

in the Rules Docket for examination by

interested persons. A report that

summarizes each FAA-public contact

concerned with the substance of this

proposal will be filed in the Rules

Docket.

Commenters wishing the FAA to

acknowledge receipt of their comments

submitted in response to this notice

must submit a self-addressed, stamped

postcard on which the following

statement is made: ‘‘Comments to

Docket No. 97–CE–21–AD.’’ The

postcard will be date stamped and

returned to the commenter.

Availability of NPRMs

Any person may obtain a copy of this

NPRM by submitting a request to the

FAA, Central Region, Office of the

Regional Counsel, Attention: Rules

Docket No. 97–CE–21–AD, Room 1558,

601 E. 12th Street, Kansas City, Missouri

64106.

Discussion

Service history of the Mitsubishi MU–

2B series airplanes prompted the FAA

to examine the design of these airplanes

and analyze the ability of the pilots of

these airplanes to fly and operate in

icing conditions. The FAA recently

conducted a special certification review

(SCR) for the Mitsubishi MU–2B series

airplanes. This examination shows 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. The training

issues were addressed in AD 97–20–14.

Indications are that the pilot is not

detecting or properly interpreting the

visual cues of ice build-up on the

airframe. The pilots of the airplanes

involved in the accidents did not exit

the icing conditions, but instead, relied

on the autopilot to fly the airplane. In

these accidents, the airplanes stalled

while on autopilot, which resulted in

departure from controlled flight into a

spin or near vertical spiral until ground

contact was made.

Explanation of Departure From

Controlled Flight

Airplanes that fly in these severe icing

conditions, although infrequently

encountered, can accumulate ice

formations that increase drag quickly

and raise stall speeds significantly.

Combining these elements with a loss of

airspeed can cause aerodynamic flow

separation or stall on one or both wings.

This stall can result in an uncontrolled
Federal Register / Vol. 63, No. 98 /Thursday, May 21, 1998 / Proposed Rules 27873

rolling or pitching, especially if yawing

is present at the stall. Heavy ice-induced

stalls can occur very suddenly at

airspeeds well in excess of normal stall

speeds, with no artificial warning (stick

shaker) or natural pre-stall buffet (stick

shaker) to advise the pilot that the

airplane is about to stall. If the pilot has

put the airplane controls on autopilot,

and takes no corrective actions during

the ice induced slowdown, the autopilot

then contributes to the departure from

controlled flight.

The certification tests and operation

of the MU–2B series airplanes reveal

that these airplanes have the capability

to cope with normal icing conditions.

However, the FAA’s current

understanding of freezing rain and

drizzle, known as supercooled large

drops (SLD), shows that atmospheric

icing conditions exist that exceed the

capability of the pneumatic ice

protection found on turbopropeller

airplanes, including the MU–2B series

airplanes. Flight into SLD, or freezing

rain and freezing drizzle, can cause ice

accretion on and beyond the active

portion of the de-icing boots, on the

upper and lower surfaces of the wing, as

well as other unprotected surfaces of the

airplane. The ice that forms beyond the

boots cannot be removed. Ice increases

drag, leading to decreased airspeed, and

if level flight is maintained, increased

angle-of-attack. This evolution can

ultimately lead to aerodynamic flow

separation over the wing, or stall. Ice

can also form around the engine inlets.

The accumulated ice might then loosen

and be ingested into the engine,

interrupt the airflow, and flame out the

engine at a critical time.

Relevant Service Information

Mitsubishi has issued the following

service bulletins which specify

procedures that address the concerns in

this proposed action.

• Test Instrumentation, Inc.

Document No. MU2–1001, Rev. C.,

dated June 15, 1997, and Mitsubishi

MU–2 Service Bulletin (SB) No. 231,

dated July 2, 1997: these documents

include procedures for incorporating an

audible trim-in-motion alert system to

notify the pilot that the trim is trimming

nose-up while the autopilot is engaged;

• Test Instrumentation, Inc.

Document No. MU2–5001, Rev. E.,

dated May 21, 1997, and Mitsubishi

MU–2 SB No. 232, dated July 2, 1997:

these documents include procedures for

modifying the existing pneumatic deicing system to assure that both wing

and tailplane boots are receiving enough

inflation pressure when the De-Ice

System Annunciation is in the ‘‘ON’’

position, and circuit breaker

modification is made;

• Mitsubishi MU–2 SB No. 217,

Revision B, dated November 7, 1996 and

Test Instrumentation Inc. Document No.

MU2–6005, dated September 28, 1997:

these documents include procedures for

incorporating an ice detector system

that includes an ice probe that will

enunciate the presence of actual icing

conditions.

The service bulletin specifies using a

Rosemont ice detector, part number

(P/N) 0871CT1, but this part may be

substituted with Rosemont P/N

0871HL1/HL2 or an FAA-approved

equivalent part number;

• Test Instrumentation, Inc.

Document No. MU2–4001, Rev. C, dated

June 30, 1997, and Mitsubishi MU–2 SB

No. 231, dated July 2, 1997: these

documents include procedures for

incorporating an automatic autopilot

disconnect system that turns off the

autopilot when the airspeed of the

airplane falls between 130 to 140 knots

indicated airspeed (KIAS);

• Mitsubishi MU–2 SB No. 226B,

Revision B, dated October 27, 1997: this

document includes procedures for

incorporating an auto-ignition (re-light)

system; and

• Mitsubishi MU–2 SB No. 074/74–

001, dated October 9, 1991: this

document includes procedures for

incorporating an engine ignition unit

replacement (to increase the engines

tolerance of ice) and reduce the chances

of engine flame-out during critical

phases of flight.

The FAA’s Determination

After examining the circumstances

and reviewing all available information

related to the accidents described above,

including the previously referenced

service information, the FAA has

determined that AD action should be

taken. Taking AD action is needed to

prevent departure from controlled flight

and to assist the pilot in detecting ice

accumulation on the airplane when

flying in icing conditions that exceed

the airplane’s ice protection capability,

which could result in possible loss of

control of the airplane.

Explanation of the Provisions of the

Proposed AD

Since an unsafe condition has been

identified that is likely to exist or

develop in other MU–2B series

airplanes of the same type design, the

proposed AD would require

incorporating the following:

(1) An ice detection system,

(2) A de-ice monitoring system,

(3) An automatic autopilot disconnect

system and a trim-in-motion alert

system,

(4) An engine continuous-duty

ignition unit replacement,

(5) An auto-ignition (re-light) system,

and

(6) Fabricating a placard (using 1⁄8-

inch letters) and installing this placard

within the pilot’s clear view with the

following words:

Prior to the first flight of the each day, a

negative torque sensing (NTS) check and a

Propeller Feather Valve check must be

performed in accordance with the Normal

Checklist Procedures.

Proposed Compliance Time

The FAA has determined that the

compliance time of the proposed AD

should be specified in calendar time

instead of hours time-in-service.

Although the condition addressed by

the proposed 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

proposed compliance time of ‘‘12

calendar months after the effective date

of this AD’’ would not inadvertently

ground airplanes and would assure that

all owners/operators of the affected

airplanes accomplish the proposed

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
27874 Federal Register / Vol. 63, No. 98 /Thursday, May 21, 1998 / Proposed Rules

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. The Certification must

include a statement providing the

factual basis for this determination, and

the reasoning should be clear.

The FAA has determined that this

proposed AD would 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, the proposed AD is

the least costly alternatives to improve

the safety of the Mitsubishi MU–2B

series airplanes that may encounter inflight 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 two or more of these

airplanes. Ownership of more than one

MU–2B series airplane is believed to be

limited to five percent of the affected

aircraft owners. Only one of these

operators had ten or more of these

airplanes. The total number of owners

operating of 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

proposed 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 would be

subject to a total of four inspections per

year. At a nominal inspection time of

one hour per inspection and labor cost

of $60 per hour, the proposed annual

inspection costs would be

approximately $240 per airplane. These

estimates include costs for the

associated record keeping. A reasonable

range of costs arising from this proposed

AD is suggested in the following table:

Cost of capital Remaining life of aircraft

Annualized cost Present

value of

Initial Total total cost

10%/year ............................................................... 20 years ................................................................ $3,022 $3,262 $27,771

15%/year ............................................................... 20 years ................................................................ 4,110 4,350 27,230

10%/year ............................................................... 10 years ................................................................ 4,187 4,427 27,203

15%/year ............................................................... 10 years ................................................................ 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

manufacturer, detailed inspections

show that deterioration of the airframes

has been quite small, so that a 20-year

life expectancy may be a reasonable

assumption. 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 assume 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 would be approximately

$27,000 per airplane. The total

annualized cost of this proposed AD for

the U.S. fleet would be in the range of

$1 million (320×$3,200 = $1,024,000) to

$1.8 million (340×$5,400 = $1,836,000).

The present discounted value of total

costs imposed by the proposed 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

proposed AD costs would be about 3.5

percent to 9 percent (($27,000/

$800,000)×100% = 3.5% to ($27,000/

$300,000) ×100% = 9%) of the market

value of the airplane. Because the costs

imposed by the proposed AD would be

proportionately higher for less

expensive airplanes, it is likely that they

would also be proportionately higher for

smaller, less financially strong operators

than for larger operators.

Based on the above-referenced

conditions, the proposed AD would

have a substantial economic impact on

a significant number of small entities.

Cost Versus Benefits

The purpose of the proposed AD is to

improve flight safety under icing

conditions for Mitsubishi MU–2B series

airplanes. The National Transportation

Safety Board (NTSB) Accident-Incident

Database indicates that three Mitsubishi

MU–2B airplane accidents occurred

from 1982 through 1996, with a total of

14 fatalities. All three accidents were

related to loss of control of the airplane

while flying in severe icing conditions.

These three airplane accidents amount

to about one percent of the MU–2B

series airplane fleet. All were part 91

operations.

In one of these accidents, involving

eight fatalities in 1996, the pilot

continued flight into (unforecast) severe

icing conditions with known inoperative anti-ice gear. The NTSB report

attributed the accident to flying with

known equipment deficiencies and

failure to maintain airspeed.

In a second accident, involving five

fatalities in 1990, the NTSB noted that

the probable cause included improper

flight planning, which resulted in flight

into icing conditions, along with failure

to maintain adequate airspeed and

control. Pilot inexperience in this

Mitsubishi MU–2B series airplane was

also cited as a related factor.

In a third accident involving one

fatality in 1988, the pilot was the sole

occupant. The pilot of the 1988 accident

reported an uncontrolled descent

shortly after starting to climb, following

a descent that had been made in order

to remove structural icing. Although the

reason for this accident was indicated to

be undetermined, the airplane was

believed to have had problems with

cabin pressurization, as well as some

structural damage associated with

landing in an overweight condition,

prior to encountering the icing. Crew

error was found to be one of the causes

of the first two accidents, and seems
Federal Register / Vol. 63, No. 98 /Thursday, May 21, 1998 / Proposed Rules 27875

likely in the third accident. Timely

warnings of the ice forming on the

airframe may have prevented some or

all of these accidents.

In developing this Regulatory

Flexibility Analysis several alternatives

to proposing this AD were considered.

The alternatives included: (1) taking no

action, including issuance of the

proposed AD, (2) requiring additional

training and the provision of special

instructions relating to operating in

icing conditions for MU–2B series

pilots, (3) banning the MU–2B series

airplanes from flights into known or

suspected icing conditions, and (4)

issuing the proposed AD.

Alternative (1): taking no action.

Taking no action would 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.

Alternative (2): requiring additional

training. A requirement for additional

training is addressed in AD 97–20–14,

Amendment 39–10150 (62 FR 51594)

issued on September 26, 1997, which

requires periodic training of pilots and

crew flying any Mitsubishi MU–2 series

airplane into possible or forecast icing

conditions. This training should assist

in reducing future ice-related accidents

for the affected airplanes.

Alternative (3): banning flight into

known or suspected icing conditions.

Banning flight into known or suspected

icing conditions would not eliminate

inadvertent encounters with icing

conditions aloft. Such restrictions may

have little effect flying into unforecast

icing conditions with inoperable antiice equipment and insufficient flight

planning. Unknown forecast conditions

aloft and insufficient flight planning

contributed to two of the accidents (and

13 of the 14 fatalities) cited. In addition,

such a ban would impose costs on

owners/operators in the form of

significant losses in value for the

airplanes, since the airplanes would be

prevented from making flights, despite

being outfitted with anti-ice equipment.

Alternative (4): issuing the proposed

AD. Issuing the proposed AD would

result in the installation of equipment

that would provide a timely warning at

the onset of icing conditions, so that

most accidents resulting from

inadvertent encounters with severe

icing conditions could possibly be

prevented.

A benefit/cost comparison for this

proposed AD can be made by noting

that the present value of the costs

imposed by this rule are on the order of

$9 million. The present value of a single

life saved sometime over the next 20

years (making use of the Department of

Transportation’s value for an avoided

fatality of $2.7 million) is approximately

$1.43 million. This figure reflects 1/20

of an annual avoided fatality ($2.7

million / 20 = $135,000) discounted

over 20 years at the Office of

Management and Budget-specified

discount rate of 7 percent.

With these figures in mind, the

proposed AD would have benefits in

excess of costs if it were to result in the

avoidance of a single accident that

involves 6 or 7 fatalities ($9 million /

$1.43 million = 6.29 avoided fatalities)

over the next 20 years. Adding the

benefit of avoiding the loss of an

airplane worth nearly a half million

dollars to the benefit presented above

increases the benefits relative to costs

related to the proposed actions.

Although it may be assumed that

current operators of these airplanes are

now aware of the dangers posed by icing

conditions, so that icing-related

accidents are now less likely than in the

recent past, the avoidance of 6 or 7

icing-related fatalities over the next 20

years is not implausible. These

airplanes can carry up to 12 passengers

and crewmembers. The past 10 years’

experience implies an annual icingrelated accident rate of 0.33 (3/10 =

0.33) with an annual icing-related

fatality rate of 1.4 (14/10 = 1.4). Seven

avoided fatalities over the next 20 years

implies an annual avoided fatality rate

of 0.35 (7/20 = 0.35), or one-fourth of

the average Mitsubishi MU–2B airplane

icing-related fatality rate observed over

the past 10 years.

For reasons outlined above, the FAA

has determined that the proposed AD is

likely to have benefits in excess of costs

and is not aware of a less costly

alternative that would be likely to bring

about a significant improvement in the

safety of Mitsubishi MU–2B series

airplanes that encounter in-flight icing

conditions.

Regulatory Impact

The regulations proposed herein

would not have substantial direct effects

on the States, on the relationship

between the national government and

the States, or on the distribution of

power and responsibilities among the

various levels of government. Therefore,

in accordance with Executive Order

12612, it is determined that this

proposal would not have sufficient

federalism implications to warrant the

preparation of a Federalism Assessment.

For the reasons discussed above, I

certify that this action (1) is not a

‘‘significant regulatory action’’ under

Executive Order 12866; (2) is not a

‘‘significant rule’’ under DOT

Regulatory Policies and Procedures (44

FR 11034, February 26, 1979); and (3) if

promulgated, will have a significant

economic impact, positive or negative,

on a substantial number of small entities

under the criteria of the Regulatory

Flexibility Act. A copy of the draft

regulatory evaluation prepared for this

action has been placed in the Rules

Docket. A copy of it may be obtained by

contacting the Rules Docket at the

location provided under the caption

ADDRESSES.

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Safety.

The Proposed Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration proposes to amend part

39 of the Federal Aviation Regulations

(14 CFR part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 USC 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding a new airworthiness directive

(AD) to read as follows:

Mitsubishi Heavy Industries, Ltd.: Docket

No. 97–CE–21–AD.

Applicability: Models 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,

and MU–2B–60 airplanes (all serial

numbers), certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

modified, altered, or repaired in the area

subject to the requirements of this AD. For

airplanes that have been modified, altered, or

repaired so that the performance of the

requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (i) of this AD. The

request should include an assessment of the

effect of the modification, alteration, or repair

on the unsafe condition addressed by this

AD; and, if the unsafe condition has not been

eliminated, the request should include

specific proposed actions to address it.

Compliance: Required within the next 12

calendar months after the effective date of

this AD, unless already accomplished.

To prevent departure from controlled flight

and to assist the pilot in detecting ice

accumulation on the airplane when flying in

icing conditions that exceed the airplane’s

ice protection capability, which could result

in possible loss of control of the airplane,

accomplish the following:
27876 Federal Register / Vol. 63, No. 98 /Thursday, May 21, 1998 / Proposed Rules

(a) Incorporate an ice detection system in

accordance with the instructions in

Mitsubishi MU–2 Service Bulletin (SB) No.

217, Revision B, dated November 7, 1996,

and Test Instrumentation Inc. Document No.

MU2–6005, dated September 28, 1997.

Note 2: The Rosemount ice detection probe

(part number (P/N) 0871 HL1/HL2 or an

FAA-approved equivalent part number) may

be substituted for the Rosemount P/N

0871CT1 called out in Mitsubishi MU–2B SB

No. 217, Revision B, dated November 7,

1996, and Test Instrumentation Inc.

Document No. MU2–6005, dated September

28, 1997.

(b) Incorporate a pneumatic de-ice

monitoring system in accordance with the

instructions in Test Instrumentation, Inc.

Document No. MU2–5001, Rev. E., dated

May 21, 1997, and Mitsubishi MU–2 SB No.

232, dated July 2, 1997.

(c) Incorporate a trim-in-motion alerting

system and an automatic autopilot

disconnect system in accordance with the

instructions 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.

(d) Incorporate an engine ignition unit

replacement in accordance with the

instructions in Mitsubishi MU–2B SB No.

074/74–001, dated October 9, 1991.

(e) Incorporate an auto-ignition (re-light)

system in accordance with the instructions in

Mitsubishi MU–2 SB No. 226B, Revision B,

dated October 27, 1997.

(f) Fabricate a placard with the following

words and install this placard within the

pilot’s clear view:

Prior to the first flight of the day, a negative

torque sensing (NTS) check and a Propeller

Feather Valve check must be performed in

accordance with the Normal Checklist

Procedures.

(g) Paragraph (f) of this AD can be

accomplished by the owner/operator holding

at least a private pilot certificate as

authorized by section 43.7 of the Federal

Aviation Regulations (14 CFR 43.7), and must

be entered into the aircraft records showing

compliance with this AD in accordance with

section 43.9 of the Federal Aviation

Regulations (14 CFR 43.9).

(h) Special flight permits may be issued in

accordance with sections 21.197 and 21.199

of the Federal Aviation Regulations (14 CFR

21.197 and 21.199) to operate the airplane to

a location where the requirements of this AD

can be accomplished.

(i) An alternative method of compliance or

adjustment of the compliance time that

provides an equivalent level of safety may be

approved by the Manager, Small Airplane

Directorate, 1201 Walnut, suite 900, Kansas

City, Missouri 64106. The request shall be

forwarded through an appropriate FAA

Maintenance Inspector, who may add

comments and then send it to the Manager,

Small Airplane Directorate.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Small Airplane

Directorate.

(j) All persons affected by this directive

may obtain copies of the documents referred

to herein upon request to Mitsubishi Heavy

Industries America, Inc., 15303 Dallas

Parkway, suite 685, LB–77, Dallas, Texas; or

may examine these documents at the FAA,

Central Region, Office of the Regional

Counsel, Room 1558, 601 E. 12th Street,

Kansas City, Missouri 64106.

Issued in Kansas City, Missouri, on May

13, 1998.

Michael Gallagher,

Manager, Small Airplane Directorate, Aircraft

Certification Service.

[FR Doc. 98–13517 Filed 5–20–98; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Parts 91 and 150

[Docket No. 2923]

Compatible Land Use Planning

Initiative

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Request for comments.

SUMMARY: The FAA is seeking new ideas

regarding how the agency can better

influence land use decisions around

airports. Noise contours around airports

will continue to shrink with the

elimination of noisier Stage 2 airplanes

by the year 2000. The FAA now seeks

to develop a process that will better

influence long-term land use planning

and zoning around airports. This notice

solicits suggestions about methods the

FAA can use to encourage and help

State and local governments achieve

and maintain land use compatibility

around airports.

DATES: Comments must be received on

or before June 22, 1998.

ADDRESSES: Comments should be

mailed in triplicate to: Federal Aviation

Administration, Office of the Chief

Counsel, Attention: Rules Docket (AGC–

200), Docket No. 29231, 800

Independence Avenue, SW.,

Washington, DC 20591. Comments may

also be sent electronically to the Rules

Docket by using the following Internet

address: 9-nprm-cmts@faa.dot.gov.

Comments must be marked Docket No.

29231. Comments may be examined in

the Rules Docket in Room 915G on

weekdays between 8:30 a.m. and 5:00

p.m., except on Federal holidays.

FOR FURTHER INFORMATION CONTACT:

Alan Trickey, Policy and Regulatory

Division, AEE–300, Federal Aviation

Administration, 800 Independence

Avenue, SW., Washington, DC 20591;

telephone, (202) 267–3496; facsimile,

(202) 267–5594; email,

alan.trickey@faa.dot.gov.

SUPPLEMENTARY INFORMATION:

Background

Aircraft noise is a serious problem for

communities around airports. Federal,

state and local governments have spent

several billion dollars for the acquisition

of land, soundproofing, changes in

airport operations and airspace, and

processing of complaints. The airline

industry has expended billions more to

acquire quieter aircraft that reduce noise

exposure levels. Although this

collective effort has resulted in

significant progress, additional

measures are needed to maintain

current gains and prevent the

development of new noncompatible

land uses around airports.

The FAA has been actively engaged in

measures to solve the problem of aircraft

noise since the 1960’s. Specifically, the

FAA has issued regulations phasing out

noisier airplanes. The noisiest Stage 1

airplanes were phased out of

commercial operations in the United

States by 1988. The current phaseout

will eliminate large Stage 2 airplanes

from operations in the contiguous

United States by the year 2000. The

FAA provides grants to airport operators

willing to undertake noise abatement

measures such as the purchase of land

and soundproofing of residences.

Based on several studies, the FAA

expects noise contours at most airports

to continue to shrink for several years

into the 21st century due to the

elimination of noisier aircraft. After the

completion of the Stage 2 phaseout by

the year 2000, the FAA anticipates that

these contours could begin to expand

again at some airports primarily due to

increases in operations. It is essential for

local jurisdictions to plan ahead to

maintain the land use compatibility

already achieved near airports and to

control land uses to prevent new noisesensitive development within an agreed

upon protection zone.

The U.S. Constitution, gives

individual States the authority over land

use, though such authority is often

delegated to local governments. Some

airports are operated by the state or

municipal governments that have the

power to achieve appropriate land use

controls through zoning and other

authorities. But even when

governmental bodies are themselves

airport operators, the noise effects of

their airports often occur in areas

outside their jurisdictions. Land use

decisions generally reflect the needs of

the community, which include but are