66512 Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

97–26–10 Raytheon Aircraft Company

(Formerly Raytheon Aircraft

Corporation; Beech Aircraft

Corporation; Raytheon Corporate Jets,

Inc.; British Aerospace, PLC;

deHavilland; Hawker Siddeley):

Amendment 39–10253. Docket 97–NM–

140–AD.

Applicability: Model Hawker 1000 series

airplanes; serial numbers 258151, 258159,

and 259003 through 259052 inclusive;

certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

otherwise modified, altered, or repaired in

the area subject to the requirements of this

AD. For airplanes that have been modified,

altered, or repaired so that the performance

of the requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (b) 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.

To prevent contact between the cowl

sealant surface and the lever of the engine

mechanical over-speed control system, which

could cause the over-speed system to

function improperly and consequent engine

structural failure; accomplish the following:

(a) Within 150 flight hours or 3 months

after the effective date of this AD, whichever

occurs first, modify the aft core cowl nozzles

of the left- and right-hand engine nacelles in

accordance with Raytheon Service Bulletin

SB.71–48–25F021B, dated May 20, 1997.

Note 2: The Raytheon service bulletin

references Nordam Hawker 1000 Service

Bulletin PW300 71–9, dated April 29, 1995,

as the appropriate source of service

information for accomplishment of the

modification.

(b) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Wichita

Aircraft Certification Office (ACO), FAA,

Small Airplane Directorate. Operators shall

submit their requests through an appropriate

FAA Principal Maintenance Inspector, who

may add comments and then send it to the

Manager, Wichita ACO.

Note 3: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Wichita ACO.

(c) 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.

(d) The modification shall be done in

accordance with Raytheon Service Bulletin

SB.71–48–25F021B, dated May 20, 1997.

This incorporation by reference was

approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from Raytheon Aircraft Company, Manager,

Service Engineering, Hawker Customer

Support Department, P.O. Box 85, Wichita,

Kansas 67201–0085. Copies may be inspected

at the FAA, Transport Airplane Directorate,

1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Small Airplane

Directorate, Wichita Aircraft Certification

Office, 1801 Airport Road, Room 100, MidContinent Airport, Wichita, Kansas; or at the

Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington,

DC.

(e) This amendment becomes effective on

January 23, 1998.

Issued in Renton, Washington, on

December 11, 1997.

Gilbert L. Thompson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–32998 Filed 12–18–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 97–NM–46–AD; Amendment

39–10249; AD 97–26–06]

RIN 2120–AA64

Airworthiness Directives; Empresa

Brasileira de Aeronautica, S.A.

(EMBRAER) Model EMB–120 Series

Airplanes

AGENCY: Federal Aviation

Administration, DOT.

ACTION: Final rule.

SUMMARY: This amendment adopts a

new airworthiness directive (AD),

applicable to all EMBRAER Model

EMB–120 series airplanes, that requires

revising the Airplane Flight Manual

(AFM) to include requirements for

activation of the ice protection systems,

and to add information regarding

operation in icing conditions. This

amendment also requires installing an

ice detector system and revising the

AFM to include procedures for testing

system integrity. This amendment is

prompted by reports indicating that

flightcrews experienced difficulties

controlling the airplane during (or

following) flight in normal icing

conditions, when the ice protection

system either was not activated when

ice began to accumulate on the airplane,

or the ice protection system was never

activated. These difficulties may have

occurred because the flightcrews did not

recognize that a significant enough

amount of ice had formed on the

airplane to require activation of the

deicing equipment. The actions

specified by this AD are intended to

ensure that the flightcrew is able to

recognize the formation of significant

ice accretion and take appropriate

action; such formation of ice could

result in reduced controllability of the

airplane in normal icing conditions.

DATES: Effective January 23, 1998.

The incorporation by reference of

certain publications listed in the

regulations is approved by the Director

of the Federal Register as of January 23,

1998.

ADDRESSES: The service information

referenced in this AD may be obtained

from EMBRAER, Empresa Brasileira De

Aeronautica S/A, Sao Jose Dos Campos,

Brazil. This information may be

examined at the Federal Aviation

Administration (FAA), Transport

Airplane Directorate, Rules Docket,

1601 Lind Avenue, SW., Renton,

Washington; or at the FAA, Small

Airplane Directorate, Atlanta Aircraft

Certification Office, Campus Building,

1701 Columbia Avenue, suite 2–160,

College Park, Georgia; or at the Office of

the Federal Register, 800 North Capitol

Street, NW., suite 700, Washington, DC.

FOR FURTHER INFORMATION CONTACT:

Carla Worthey, Aerospace Engineer,

Systems and Flight Test Branch, ACE–

116A, FAA, Small Airplane Directorate,

Atlanta Aircraft Certification Office,

Campus Building, 1701 Columbia

Avenue, suite 2–160, College Park,

Georgia 30337–2748; telephone (770)

703–6062; fax (770) 703–6097.

SUPPLEMENTARY INFORMATION: A

proposal to amend part 39 of the Federal

Aviation Regulations (14 CFR part 39) to

include an airworthiness directive (AD)

that is applicable to all EMBRAER

Model EMB–120 series airplanes was

published in the Federal Register on

May 13, 1997 (62 FR 26258). That action

proposed to require revising the

Airplane Flight Manual (AFM) to

include requirements for activation of

the ice protection systems, and to add

information regarding operation in icing

conditions. That action also proposed to

require installing an ice detector system

and revising the AFM to include

procedures for testing system integrity.

Interested persons have been afforded

an opportunity to participate in the

making of this amendment. Due

consideration has been given to the

comments received.

Support for the Proposal

Several commenters support the

FAA’s intent to revise the FAAapproved AFM procedures for flight in
Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations 66513

icing conditions and/or to require

installation of an ice detector system.

Compliance Time To Install Ice

Detector

Two commenters request additional

time to install the ice detector system.

One of the commenters states that the

manufacturers of the ice detector

installations (Grimes for the cockpit

indications, and Rosemount Aerospace

for the ice detector) will not have kits

available for all U.S. operators until the

end of January 1998, although at least

120 kits were available on October 31,

1997. The other commenter states that 6

months is an unreasonable schedule for

retrofitting their fleet of aircraft and

requests a 24-month compliance time.

Another commenter requests additional

time to provide operators the

opportunity to consider other options of

ice detection and flightcrew response to

such conditions, as proposed under the

FAA’s Inflight Aircraft Icing Plan. The

commenter did not request a specific

period of time for the extension.

The FAA concurs that the compliance

time can be extended somewhat, since

parts will not be available for all aircraft

early enough to allow completion

within 6 months. The FAA finds that,

once parts are available, operators must

comply with the AD prior to the next

icing season. Therefore, paragraph (b) of

the final rule has been revised to specify

a compliance time of 10 months after

the effective date of the AD. The FAA

does not consider that this extension

will adversely affect safety. If an

operator obtains FAA design and

installation approval for an alternative

to the ice detector, the operator may

request approval of an alternative

method of compliance in accordance

with paragraph (c) of the final rule.

Master Minimum Equipment List

(MMEL) Requirements

One commenter requests that any ice

detection equipment installed on an

aircraft must be operational prior to

dispatch into known or forecasted icing

conditions. Two other commenters

request that the MMEL grant relief for

dispatch with inoperative ice detector

equipment.

The FAA acknowledges the

commenters’ requests. However, MMEL

requirements are determined by the

FAA Flight Operations Evaluation

Board (FOEB). The FOEB has

determined that it is permissible to

dispatch with an inoperative ice

detection system provided that all ice

protection systems are turned on (except

leading edge deicing during takeoff) and

AFM limitations and normal procedures

for operating in icing conditions are

complied with whenever operating in

visible moisture at temperatures below

10 degrees Centigrade (50 degrees

Fahrenheit). Revision 5c of the MMEL

for EMBRAER Model EMB–120 series

airplanes, dated October 9, 1997,

incorporated this relief.

Additional Analysis

One commenter states that flight

control difficulties of the airplanes in

icing conditions were reported and

known as far back as 1989, but action

is only being taken now. The

commenter requests that additional

analysis be conducted on the previous

icing events, and the proposal be

revised based on the results of that

analysis. The commenter believes that

the proposed AD tends to fall short of

what is required to preclude subsequent

reports of aircraft control problems on

Model EMB–120 series airplanes.

The FAA does not concur that

additional analysis is required. The

initial certification test data for flight

into known icing approval indicate that

Model EMB–120 series airplanes meet

all of the certification requirements

specified in Appendix C of part 25

(‘‘Airworthiness Standards: Transport

Category Airplanes’’) of the Federal

Aviation Regulations (14 CFR part 25),

provided the ice protection systems are

activated properly. In addition,

available information concerning the

roll upset event history of the EMB–120

has been analyzed thoroughly by the

FAA; the Centro Tecnico Aeroespacial

(CTA), which is the airworthiness

authority for Brazil; and the airplane

manufacturer. That analysis indicates

that the flightcrews did not activate the

de-ice boots prior to the roll upset

events. Based on this analysis, the FAA

has determined that sufficient data exist

to require that an AD be issued to

ensure that the flightcrew is able to

recognize the formation of significant

ice accretion and take appropriate

action.

Another commenter requests that roll

upset, tailplane icing, and

uncommanded roll and/or pitch studies

be completed prior to issuing the final

rule. The commenter also suggests that

additional research should be done

regarding the location of ice detectors

on the airframe.

The FAA does not concur that

additional research is needed. Roll

upset, tailplane icing, and

uncommanded roll and/or pitch studies

have been completed, as suggested by

the commenter.

Further review of the event history

revealed occurrences of controllable

departures from normal flight in icing

conditions after loss in airspeed when

the ice protection systems of the lifting

and control surfaces were not activated.

Additionally, operational experience

and flight testing conducted by the

manufacturer indicate that maintaining

proper airspeeds and the additional

action of activating the ice protection

system at the first detection of airframe

icing will eliminate future occurrences

of roll upset events.

The FAA finds that supplementing

appropriate visual cues for icing with

dependable detection and annunciation

of encountering icing conditions by an

ice detector will ensure flightcrew

recognition of icing conditions. In

addition, the revision of the FAAapproved AFM, as required by this final

rule, will help to ensure activation of

the ice protection system, regardless of

whether detection of icing is from visual

cues or the ice detector, and will require

appropriate minimum operating speeds.

The FAA finds that additional

research need not be done regarding the

location of ice detectors. The FAA and

CTA have already conducted a thorough

review of that issue, including analysis

of flight test data that show that the

proposed location of the ice detector

will provide early and consistent

indication of ice accretion on the

airframe.

‘‘Bridging’’ Phenomenon

Several commenters express concern

that the FAA proposal to mandate use

of the deicing equipment at the first sign

of ice accretion, rather than delaying

until 1⁄4- to 1⁄2-inch ice has accumulated,

could result in ice forming the shape of

an inflated boot, which would make

further attempts to de-ice difficult.

These commenters request that this

phenomenon, commonly referred to as

‘‘bridging,’’ be addressed in terms of its

validity prior to mandating the change

to the AFM procedures. Another

commenter noted that, even though the

manufacturer already issued Revision

43, dated April 23, 1996, of the AFM to

indicate the ice protection systems

should be activated with the first sign of

ice accretion, some operators continue

to caution pilots about ‘‘prematurely’’

activating the de-ice boots because of

the ‘‘bridging’’ concern.

The FAA does not concur that it is

necessary to withdraw the proposal

until ‘‘bridging’’ is addressed further.

The FAA is aware that the ‘‘bridging’’

condition continues to influence the

attitudes of many pilots and operators

with respect to the use of de-ice boots.

However, prior to approving Revision

43 of the AFM, the FAA and CTA, along

with the manufacturer, investigated

activating the de-ice boots at the first

sign of ice to determine whether
66514 Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations

‘‘bridging’’ of the de-ice boots was a

concern. It was noted that the de-ice

system is controlled by a timer that

inflates the de-ice boots in a threeminute cycle in ‘‘light’’ mode and in a

one-minute cycle in ‘‘heavy’’ mode.

Since there are approximately three

minutes when the boots are deflated in

the ‘‘light’’ cycle, it is likely that

inflation cycles have already been

occurring in service with less than the

earlier recommended 1⁄4- to 1⁄2-inch ice

accumulation, with no documented

indication of ‘‘bridging.’’

The FAA was not able to find

documented evidence of ‘‘bridging’’

occurring on the airplane. The National

Transportation Safety Board (NTSB)

also noted in its response to the

proposed rule that it ‘‘* * * knows of

no documented evidence of ‘bridging’

occurring on current generation

turbopropeller airplanes.’’ Moreover, deicing system technology has improved

over the years by using higher pressures,

smaller chambers, more rapid inflation

and deflation, and greater coverage of

the leading edge, which have increased

the system’s ability to shed smaller

accretions.

Unsafe Condition

Two commenters state that the Model

EMB–120 series airplane has completed

extensive testing in icing conditions and

was found to have no adverse flight

characteristics associated with ice

accreted on the aircraft. Additionally, it

was found to perform well within

established safety parameters. This

testing included natural icing tests

within icing conditions specified in

Appendix C of part 25 of the Federal

Aviation Regulations (14 CFR part 25) as

part of the original icing certification,

testing of ice contaminated tailplane

stall characteristics, and subsequent

investigations of susceptibility to roll

control anomalies following flight in

supercooled large droplet icing

conditions. One commenter states that

the airplane was properly certified for

flight into known or forecast icing

conditions in 1985, and remains in

complete compliance with current icing

requirements and all FAA policies,

practices, and procedures.

Two commenters state that all turboprop aircraft are tested to the same

criteria, and that if the EMB–120

requires an ice detector, then all turboprop aircraft should be required to

install a detector. Another commenter

states that the justification given for the

AD to ‘‘enable the flight crew to more

accurately determine the need to

activate the ice protection systems on

the airplane and to take appropriate

action’’ is insufficient reason to

distinguish Model EMB–120 series

airplanes from other airplane models.

Another commenter notes that

another aircraft type with an ice

detector system installed experienced a

recent accident (Roselawn, Indiana)

where icing conditions were determined

to be a contributing cause. The

commenter states that after the

Roselawn accident, the FAA, in

conjunction with the Brazilian aviation

certification authorities, conducted an

extensive review of the Model EMB–120

series airplanes and concluded that the

aircraft was safe to fly in inadvertent

icing environments without adverse

handling or flight characteristics.

The FAA infers that these

commenters request the FAA withdraw

the notice of proposed rulemaking

(NPRM), since they believe that an

unsafe condition has not been

established. The FAA acknowledges the

previous testing and results. However, a

review of the service history of Model

EMB–120 series airplanes reveals that

there have been several roll upset events

in icing conditions, that the flightcrews

did not activate the de-ice system prior

to the events, and that they did not

maintain proper airspeed. This indicates

the flightcrews were either unaware of

the ice accretion or underestimated the

depth of ice accreted and the resultant

loss in airplane performance, and

delayed activation of the de-ice system

too long. As stated in the NPRM, it is

this lack of recognition of icing

conditions, and the consequent failure

to deploy the ice protection systems,

rather than the performance of the

airplane once this system is activated,

that constitute the unsafe condition

addressed by this AD. In this regard, the

service history of the Model EMB–120 is

significantly different from that of other

turbo-prop aircraft. The requirements of

the final rule will increase the level of

pilot awareness, ensure appropriate

flightcrew actions, and increase the

operational level of safety over that

which currently exists.

As further information is obtained,

the FAA may consider addressing the

question of requiring an ice detector to

supplement visual icing cues for all

commercial air transports as a part of

future rulemaking actions.

Flightcrew Training

Several commenters request that crew

training be instituted to increase pilot

awareness of the criticality of aircraft

performance degradation during an

icing encounter, in lieu of the proposed

rule to mandate installation of an ice

detector.

One of these commenters states that

the installation of an ice detector is not

necessary, is overly burdensome, and

that proper training of the flightcrews to

the visual cues associated with ice

formation on the propeller spinner is

the best solution.

Another commenter, the

manufacturer, states that the FAA’s

review of the icing related incidents

cited in the proposed rule revealed that

pilot indecision (as to when to activate

the aircraft’s de-ice system), and the

lack of appreciation of the criticality of

aircraft performance degradation during

an icing encounter were the basic causes

of the reported icing occurrences. The

manufacturer concludes that, in

addition to mandating immediate

activation of the de-ice system,

improved pilot training and recurrent

training is needed to ensure that the

information gained in recent years about

icing is passed along to line pilots.

A third commenter agrees with the

proposed requirement to install an ice

detection system, but notes that pilots

have been trained for years to operate

the de-ice boots only after 1⁄4- to 1⁄2-inch

of ice has accumulated on the wings.

The commenter states that the pilots

need to be provided training to unlearn

old habits and to emphasize the new

icing procedures.

The FAA does not concur that

substituting training for installation of

an ice detector is an adequate solution

to address the unsafe condition.

However, the FAA supports the

development of advisory materials and

periodic training to increase awareness

of the potential for aircraft performance

degradation during an icing encounter,

including ensuring that flightcrews are

aware of the visual icing cues available

to determine if the aircraft is in severe

icing conditions. The FAA

acknowledges that pilot indecision as to

when to activate the de-ice system may

have been a factor in the roll upset

events. Training to ensure that

flightcrews activate the ice protection

systems at the first sign of ice

accumulation will help address this

issue. Part 121 (‘‘Certification and

Operations: Domestic, Flag, and

Supplemental Air Carriers and

Commercial Operators of Large

Aircraft’’) of the Federal Aviation

Regulations (14 CFR part 121), and part

135 (’’Air Taxi Operators and

Commercial Operators,’’) of the Federal

Aviation Regulations (14 CFR part 135),

require that appropriate training

concerning limitations such as those

contained in this AD are incorporated

into air carriers’ training programs.

However, based on the roll upset

event history of Model EMB–120 series

airplanes, the FAA considers that the

use of advisory materials and training
Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations 66515

alone are not adequate to address the

subject unsafe condition. Therefore, the

FAA has determined that installation of

an ice detection system is necessary to

achieve an acceptable operational level

of safety.

Availability of Adequate Visual Cues

Several commenters request that the

requirement for an ice detection system

be removed from the proposal because

the visual cues of ice accumulation

already provide notification of icing

conditions. One of the commenters

further states that the ice detector is

simply another indicator of the presence

of ice, and that it does not have the

ability to measure ice or alert the crews

to icing environments beyond the

capability of the de-ice system.

The manufacturer states that the

FAA’s brief discussion of the icing

related incidents in the NPRM indicates

that the natural visual cues of icing

accretions are unsatisfactory or

insufficient, thus necessitating the

installation of the additional means of

ice detection. The manufacturer

disagrees with this conclusion because

a review of the icing related incidents

cited in the NPRM indicates that the

common contributing factor to the icing

related incidents was a lack of crew

attentiveness, rather than a lack of

availability of visual cues.

One commenter wrote that there is a

definite difference in the visual pattern

of ice buildup on the propeller spinner

between supercooled large droplet

(SLD) and ‘‘normal’’ ice buildup. The

commenter concludes that the

installation of an ice detector system is

not the best option for dealing with ice

on the aircraft.

Another commenter states that the

visual cues for detecting icing

conditions and operating de-icing

equipment are inadequate and must be

researched further.

The FAA does not concur with the

request to remove the requirement for

an ice detection system. The FAA

acknowledges that natural icing testing

conducted during the initial

certification indicated that the visual

cues for ice detection were adequate.

Later testing revealed that the visual

cues in freezing drizzle were adequate

to provide identification of possible

severe icing conditions. Nevertheless, a

review of service history reveals that in

several roll upset events in icing

conditions, the flightcrew did not

activate the de-ice system, and

subsequently allowed the airspeed to

decrease prior to the roll upset event.

The fact that the flightcrews did not

activate the de-ice system indicates that

the flightcrews were either unaware of

the ice accretion or underestimated the

depth of ice accreted, and delayed

activation of the de-ice system too long.

The FAA acknowledges the fact that

the ice detector system does not have

the ability to measure the amount of ice

or to alert crews when icing

environments are beyond the capability

of the de-ice system. The FAA concurs

that the visual cues associated with the

SLD icing conditions, including ice on

the propeller spinner farther aft than

normally observed, are adequate to

indicate severe icing conditions.

Additionally, the FAA finds that the roll

control characteristics testing in SLD

conditions has shown that once the

flightcrews are alerted that they are in

icing conditions and activate the de-ice

system, the handling characteristics are

adequate to allow the crews to safely

exit the severe icing conditions.

Therefore, an adequate level of safety

will be provided by alerting the crew

that they are in icing conditions and

requiring them to immediately activate

the de-ice system. (Since the crew will

be alerted to the presence of icing

conditions, they will be able to monitor

the aircraft for the visual cues associated

with severe icing conditions, in

accordance with the procedures

currently provided in the FAAapproved AFM, and take appropriate

action.)

The FAA does not concur that further

research is warranted before issuance of

the final rule. The visual cues available

for detecting ice accumulation have

already been defined for both Appendix

C of part 25 of the Federal Aviation

Regulations (14 CFR part 25), and SLD

icing conditions; further research is

unlikely to improve these available

cues. However, the roll upset events

indicate that flightcrews relying on

these visual cues are not consistently

activating the de-ice system at the

proper time. Therefore, installation of

an ice detection system which provides

early and active annunciation to the

flightcrew that they are in icing

conditions, in conjunction with

continuous flightcrew monitoring of the

visual cues available, is necessary to

provide an acceptable level of safety.

Installation of Ice Evidence Probe

One commenter indicates that it

disagrees with the need to install an ice

detection system. However, if the FAA

requires some additional means other

than visual cues to assist the crews in

identifying icing conditions, the

commenter suggests installing an ice

evidence probe similar to the probe

installed on Aerospatiale Model ATR

series airplanes instead of an ice

detector. Such a probe would indicate

the first sign of ice on the airframe and

would also be the last location to have

ice sublimate from the airframe. The

commenter states that the installation of

this type of probe would require a

minimum amount of time to install, and

would take less time to train flightcrews

in its operation than the proposed ice

detection system.

The FAA does not concur that an ice

evidence probe should be required to be

installed in lieu of an ice detector. The

FAA finds that the service histories of

Model EMB–120 series airplanes and

Aerospatiale Model ATR series

airplanes warrant different approaches

to satisfy an acceptable level of safety.

An ice evidence probe is a passive

device that would provide another

visual indication of ice accretion, but

would require the flightcrew to monitor

and assess the appearance of the probe

in order to be effective. Conversely, the

ice detection system is an active system

that provides an amber light on the

multiple alarm panel, an aural warning

system chime, and illumination of the

master caution light. These multiple

indications provide early and active

notification to the flightcrew that they

are in icing conditions. The ice

detection system also provides a high

level of pilot awareness without

constant monitoring, and will increase

the level of safety over the installation

of a passive system such as an ice

evidence probe. Consequently, the FAA

has determined that the service history

of Model EMB–120 series airplanes

warrants installation of an ice detector

to meet an acceptable level of safety.

Proposed Ice Detection System

One commenter states that ice

detection equipment installed on an

aircraft must have the capability of

detecting all types and severity of ice

accretions, as specified in Appendix C

of part 25 of the Federal Aviation

Regulations (14 CFR part 25), as well as

those types and severities of ice

accretions outside the scope of

Appendix C. The commenter further

states that such a system must also have

the capability to differentiate between

the two conditions and annunciate to

the flightcrew which condition is being

encountered. Additionally, the

commenter states that monitoring of

icing conditions should be conducted at

all times during a flight. The commenter

also states that any ice detection

equipment installed on an aircraft

should be considered an aid to

flightcrew recognition and should not

be considered a primary ice detection

method.

The FAA does not concur with the

commenter’s suggestion that ice
66516 Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations

detection equipment must have the

capability to differentiate between the

severity and types of ice accretion. The

intent of this AD is to ensure that the

flightcrew is able to recognize the

formation of ice accretion and to take

appropriate action. It is unnecessary to

provide an ice detector that is capable

of distinguishing between icing

conditions that are defined in Appendix

C and those icing conditions that are not

defined in Appendix C in order to

accomplish this intent.

The FAA has determined that the

combination of early ice detection and

the additional visual cues associated

with severe icing conditions are

adequate to determine if severe icing

conditions have been encountered and

should be exited. Additionally, the roll

control characteristics testing of the

Model EMB–120 series airplane in SLD

conditions conducted in early 1996 has

shown that once the flightcrew activates

the de-ice system, the handling

characteristics are adequate to allow the

airplane to safely exit the severe icing

conditions. The installation of an ice

detection system, as required by the

final rule, will provide a clear

annunication of the presence of ice that

will alert the flightcrew to monitor the

aircraft for ice accumulation. The

flightcrew will then be responsible for

determining whether the visual cues

associated with severe icing conditions

are present and for taking appropriate

action in accordance with procedures

currently provided in the FAAapproved AFM. The FAA finds that

reliance on the flightcrew to make this

determination, in conjunction with the

installation of an ice detection system,

will provide an adequate level of safety.

The FAA concurs that the flightcrew

has the primary responsibility for

monitoring the icing conditions and for

taking appropriate action. The FAA also

concurs that the ice detection system

required by the final rule is an aid to the

flightcrew for early recognition of icing

conditions. The FAA considers the

definition of a ‘‘primary’’ ice detection

system as one that is sufficiently reliable

to serve as the sole source of

information for flightcrew recognition of

icing conditions. Primary systems do

not require the flightcrew to monitor the

icing conditions to determine if the ice

protection equipment should be

activated; the FAA does not consider

the ice detection system required by the

final rule as a ‘‘primary’’ system. Ice

accumulation is signaled by either

illumination of the ‘‘ICE CONDITION’’

light on the multiple alarm panel, or by

flightcrew observation of other visual

cues.

Installation of Ice Detector

One commenter states that

compliance with § 25.1419 of the

Federal Aviation Regulations (14 CFR

25.1419) concerning ice protection

requirements is optional. The

commenter also states that the FAA can

only mandate operational limitations on

the aircraft based on whether or not

these requirements have been met. The

commenter further states that such

limitations could be so stringent that it

would not be economical to operate the

airplane in scheduled operations.

Additionally, the commenter states that

the need to install ice detection systems

on the aircraft should be determined

solely by the operator.

The FAA does not concur. As

described in the NPRM, this AD is based

on the FAA’s finding that an unsafe

condition exists on Model EMB–120

series airplanes, not that the type design

does not comply with 14 CFR 25.1419.

The FAA has determined that the

operating limitations prescribed in this

AD are necessary to address the

identified unsafe condition. Therefore,

the FAA is fully authorized under 49

U.S.C. 44701 and 14 CFR part 39 to

impose these limitations by AD. The

FAA considers these limitations to be

highly cost effective, and the commenter

has provided no information to the

contrary.

Regarding the applicability of 14 CFR

25.1419, although the commenter is

correct that compliance with this

section is optional, the decision to

comply is made only by applicants for

type certificates (in this case,

EMBRAER), and changes to those

certificates, rather than by individual

operators. EMBRAER chose to show

compliance with 14 CFR 25.1419, and

the Model EMB–120 is therefore

permitted to operate in icing conditions.

Any operator that does not wish

approval to operate into known or

forecast icing conditions may request

approval of an alternative method of

compliance with the requirements of

this AD in accordance with the

provisions stated in paragraph (c) of the

final rule.

Conflict With FAA’s Inflight Aircraft

Icing Plan

One commenter requests that the

proposed rule be withdrawn because the

FAA’s Inflight Aircraft Icing Plan

contains a task to consider a regulation

to install ice detectors, aerodynamic

performance monitors, or other means

to warn flightcrews of ice accumulation

on critical surfaces. Therefore, the

commenter concludes that the proposed

rule is in conflict with the FAA’s

Inflight Aircraft Icing Plan.

The FAA does not concur that the

proposed rule conflicts with the FAA’s

Inflight Aircraft Icing Plan. As the

commenter stated, the icing plan does

identify a task to consider a regulation

to require ice detectors. However, in the

case of Model EMB–120 series

airplanes, the FAA has identified an

unsafe condition and has determined

that installation of an ice detector is

warranted. The potential for future

adoption of a regulation to require an

ice detector neither negates nor conflicts

with the need to correct the existing

unsafe condition.

AFM Procedures

One commenter requests that the FAA

revise paragraph (a)(2) of the NPRM

which currently requires revision of the

‘‘. . . Normal Procedures Section of the

AFM by removing any icing procedures

that contradict the procedures specified

in (a)(1) and (a)(3) of this AD. . . .’’ The

commenter requests that the FAA

specify which portions of the Normal

Procedures Section of the AFM should

be revised rather than leaving this open

to interpretation by individual

operators.

One commenter requests that the FAA

compare the recently proposed AFM

changes in NPRM Docket Number 97–

NM–46–AD to those AFM changes

mandated by AD 96–09–24, amendment

39–9600 (61 FR 20677, May 7, 1996), as

some of the procedures appear to

conflict with one another. In particular,

the commenter is concerned that the

procedure in AD 96–09–24 indicates

that flaps should be left wherever they

are, whereas the current proposed rule

indicates that flaps must be left up.

One commenter states that there is

presently no guidance to many

flightcrews to operate their deicing

equipment at the first sign of ice

accretions. The commenter further

states that this guidance must first be

evaluated for its validity and

subsequently generated for flightcrew

use.

Another commenter states that all

temperature references and limitations

specified in the proposed rule should be

referenced in terms of Indicated Outside

Air Temperature.

Two commenters request that the

FAA review the language of the

proposed AD specified in paragraph

(a)(1) to validate whether continuous

ignition should be used for extended

periods of time. The current proposal is

for a new limitation to require ‘‘Turn on

. . . Ignition Switches . . . When

atmospheric or ground icing conditions

exist.’’ One of the commenters states
Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations 66517

that operation of the ignition system on

the ground while taxiing may mask

other engine or fuel control problems. In

addition, one commenter requests that

the FAA review the language of the

proposed AD to validate whether

deicing equipment should be operated

on the ground for extended periods of

time.

One commenter notes that there is

currently no guidance provided in the

AFM concerning when to use the heavy

or light modes of operation of the ice

protection system.

One commenter questioned paragraph

(a)(3) of the proposed AD, which states:

‘‘Daily Checks of the Ice Protection

System, add the following: Ice Detector

System Test Button (if

installed) * * * Press. Check normal

test sequence.’’ The commenter states

that system reliability on similar aircraft

do not require daily tests of this system,

and that the system should be checked

prior to dispatch into known or forecast

icing conditions.

The FAA concurs that clarification is

necessary to specify which portions of

the Normal Procedures Section of the

AFM should be revised. Since the

issuance of the NPRM, the manufacturer

has advised the FAA of new, revised

procedures of the AFM. Therefore, the

FAA has clarified and combined the

requirements of paragraphs (a)(2) and

(a)(3) of the proposal into a new

paragraph (a)(2) of this final rule. The

new paragraph (a)(2) of the final rule

includes complete information to be

incorporated into the AFM under the

Normal Procedures Section for

‘‘Operation in Icing Conditions for

Flying into Icing Conditions.’’ However,

it should be noted that this information

does not replace or revise any of the

current AFM information provided

under the subsequent section of the

AFM regarding severe icing conditions.

The FAA does not concur that

procedures specified in AD 96–09–24

conflict with the procedure of this final

rule. AD 96–09–24 required revising the

AFM to provide the flightcrew with

recognition cues for severe icing

conditions and procedures for exiting

from severe icing conditions, and to

limit or prohibit the use of various flight

control devices, including flaps, in

those severe icing conditions. The

Limitations and Normal Procedures

changes included in this final rule

ensure that the flightcrew will be

advised of when to operate the ice

protection system during any icing

condition. Therefore, the FAA finds that

the change to AFM procedures do not

conflict with the earlier AD

requirements.

The FAA does not concur that

operators (flightcrews) have not been

provided guidance to operate the

deicing equipment at the first sign of ice

accretion. The FAA has approved

Revision 43 of the AFM, dated April 23,

1996. This revision included a change

in the Normal Procedures section for

flight in icing conditions to indicate that

wing and tail leading edges, engine air

inlet, and windshield ice protection

systems should be turned on at the first

sign of ice formation. The originally

approved AFM suggested a delay in

activation of the wing and tail de-ice

boots until 1⁄4- to 1⁄2-inch ice had

accumulated. However, the FAA

recognizes that not all EMB–120

operators incorporated this change in

procedures into their Operators

Manuals. Therefore, the final rule

requires that this procedure be added to

the Limitations Section of the FAAapproved AFM, as well as in the Normal

Procedures Section. As previously

stated, Federal Aviation Regulations

require that all operating limitations

such as those specified in this AD be

incorporated into air carriers’ training

programs and operators’ manuals. In

addition, as explained previously, the

FAA has already determined the

validity of the revised procedure to

activate the ice protection systems at the

first sign of ice accumulation, and has

determined that this change is required

in order to provide an adequate level of

safety.

The FAA concurs that the

temperature references specified in the

final rule should be Indicated Outside

Air Temperature, and has revised the

final rule accordingly.

The FAA does not concur that

continuous ignition should not be used

for extended periods of time or that the

operation of the ignition system on the

ground while taxiing may mask other

engine or fuel control problems. The

FAA has reviewed information

indicating that CTA, EMBRAER, and

Pratt & Whitney have reviewed

operation of continuous ignition, and

the results indicate that extended use of

continuous ignition does not have a

detrimental effect on the operation of

the engine, although it may decrease the

life of the igniters. That information also

indicated that engine or fuel control

problems are diagnosed by monitoring

other parameters available for the

flightcrew. In addition, the FAA has

reviewed the language of the AD

concerning the extended operation of

deicing equipment on the ground. The

FAA has determined that operation of

the deicing equipment for extended

periods on the ground will not result in

any adverse operating characteristics of

the deicing equipment.

The FAA concurs that there is

currently no guidance in the AFM

regarding when, or under what

conditions, to use the light or heavy

modes of the ice protection system.

However, the EMBRAER Operators

Manual recommends that the pilot

assess the severity and rate of accretion

of ice and select the appropriate mode

using pilot judgment. Paragraph (a)(2) of

the final rule has been revised to

provide that guidance by adding the

following procedures in the Normal

Procedures Section of the FAAapproved AFM under Operation in Icing

Conditions for Flying into Normal Icing

Conditions: ‘‘Visually evaluate the

severity of the ice encounter and the

rate of accretion and select light or

heavy mode (1 minute or 3 minute

cycle) based on this evaluation.’’

The FAA concurs that the ice

protection system is required to be

checked only once a day prior to

dispatch into known or forecast icing

conditions. The AFM change required

by paragraph (a) of the final rule adds

the ice detection system under ‘‘Daily

Checks of the Ice Protection System.’’

Both the CTA and the FAA interpret

this AFM guidance to mean that the

daily checks of the ice protection system

must be performed once a day before

operation into known or forecast icing

conditions, rather than before every

flight into icing. To further clarify this

procedure, the final rule has been

revised to add the following procedures

of the AFM under ‘‘Daily Checks of the

Ice Protection System:’’ ‘‘The following

tests must be performed prior to the first

flight of the day for which known or

forecast icing conditions are

anticipated.’’

Minimum Airspeed in Icing Conditions

A number of commenters question the

validity of the minimum airspeed

specified in paragraph (a)(3) of the

proposed AD that would require

addition of the following: ‘‘Operation in

Icing Conditions for Flying Into Normal

Icing Conditions: Airspeed * * * 160

KIAS Minimum. If buffet onset occurs,

increase airspeed.’’

One commenter states that buffet

onset is dangerously close to the

recommended minimum operating

speed in icing conditions and should

not be considered a prerequisite for

speed additives. The commenter further

states that the recommended minimum

speed in icing lacks empirical data to

substantiate its usage, and that any

recommended minimum speeds must be

scientifically determined.
66518 Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations

Another commenter agrees that

setting a clear 160-knot minimum

airspeed in icing conditions will

provide an immediate improvement in

safety and should be implemented.

However, the commenter questions

whether the language provided in the

proposed AD establishes appropriate

speeds for all conditions (i.e., all flap

settings and phases of flight) as

proposed in the National Transportation

Safety Board’s Safety Recommendation

A–97–31. The commenter also notes

that further tests may show that a higher

minimum airspeed is required to

provide an adequate safety margin.

Several commenters also questioned

the adequacy of the revised approach

procedure specified in paragraph (a)(3)

of the proposed AD which states:

‘‘Operation in Icing Conditions for

Flying Into Normal Icing Conditions:

Approach procedure: Increase approach

speeds (according to flap setting) by 10

KIAS until landing is assured.’’

One commenter recommends the

establishment of minimum operating

speeds for each flap configuration to

include no flaps, regardless of whether

or not the aircraft is operating in icing

conditions. With flaps up, the

commenter recommends the use of

1.4Vs @ 30° bank; for approach

procedures, the commenter

recommends the use of 1.3Vs @ 30°

bank. The commenter further

recommends that climb procedures in

the AFM be revised to reflect the higher

speeds required with ice accumulation.

Another commenter asks what

approach speed should be utilized since

an approach speed has not been defined

by the manufacturer.

The FAA concurs that clarification of

the justification of the minimum

airspeed specified in paragraph (a) of

the proposal is necessary. The 160-knot

minimum speed was defined by

EMBRAER as the recommended holding

speed for icing conditions during the

original icing certification. The

simulated ice shapes on unprotected

surfaces used for the handling qualities

and stall testing prior to icing approval

were defined using the leading edge

impingement criteria associated with

this speed. These tests demonstrated

that the aircraft can be maneuvered at

this speed (160 KIAS) up to 30° of bank

angle, the normal maximum bank angle

for holding, with an adequate stall

margin to the buffeting boundary, stick

shaker, and stick pusher with these ice

shapes on the aircraft. In addition,

natural icing tests were conducted at

this speed and ice shapes accumulated

were recorded and compared to the

simulated ice shapes to determine their

validity. These tests demonstrate that

the airplane meets the requirements

specified in part 25 of the Federal

Aviation Regulations (14 CFR part 25)

during flight in icing conditions,

provided the ice protection systems are

properly activated. The flight tests also

demonstrated that there is a minimum

airspeed margin of at least 15 knots

indicated airspeed (KIAS) in turns and

20 KIAS in level flight between the

initial buffeting with ice on the

unprotected surfaces, and the minimum

recommended airspeed of 160 KIAS.

Therefore, the FAA has determined that

the recommended minimum speed with

flaps up of 160 KIAS in icing conditions

has not only been scientifically

determined, but also has been validated

by certification flight tests and has

shown adequate margin to buffet

boundary and to stall. Consequently, the

FAA has determined that the procedure

in the proposed rule that stated ‘‘If

buffet onset occurs, increase airspeed’’

is not necessary, and has been removed

from the final rule.

The FAA concurs that appropriate

speeds for flap settings and phases of

flight following flight in icing

conditions should be provided in the

final rule. The proposed AD provided a

change to the Normal Procedures

Section of the AFM that stated: ‘‘When

flying into known or forecast icing

conditions, proceed as follows:

AIRSPEED * * * 160 KIAS MINIMUM.

If buffet onset occurs, increase

airspeed.’’ The FAA recognizes that this

proposed change does not clearly

indicate that this is the minimum speed

for the flaps up, gear up configuration

only. The FAA also acknowledges that,

without clarification, some operators

may be led to believe this is the

minimum speed for all gear and flap

configurations, even though additional

proposed information states: ‘‘Approach

procedure: Increase approach speeds

(according to flap setting) by 10 KIAS

until landing is assured.’’

Therefore, the FAA has revised the

wording in paragraph (a) of this AD to

clarify the procedures for flying into

known or forecast icing conditions,

approach and landing procedures, and

go-around procedures.

The FAA has determined that this

revised information will provide

adequate information regarding

minimum speeds to be used for all

configurations after a continuous

maximum icing encounter, which has

been determined to provide the most

severe ice accumulation on the airplane.

The FAA has further determined that no

change to the normal takeoff speeds is

necessary as ice accumulation during

this phase of flight with the ice

protection system operating should have

no impact on the flight characteristics of

the airplane, provided the takeoff is

accomplished with a properly de-iced

aircraft.

The FAA does not concur with the

commenter’s recommendations for

revision of in-flight minimum operating

speeds. Those speeds are established by

FAA regulations as V2 speed for takeoff,

a minimum speed of 1.25VS to meet

final takeoff climb requirements in the

cruise configuration, and a climb speed

established in connection with normal

landing procedures, but not exceeding

1.5VS to meet approach climb gradient

requirements. Landing speed is required

to be not less than 1.3VS or the

minimum control speed. These speeds,

and their associated maneuver margins

to stall warning, are in part defined by

assuming an engine failure.

Consideration is also given to ensuring

adequate maneuver and stall warning

margins as the wing trailing edge flaps

are retracted or extended. Experience

has shown these minimum speeds to be

acceptable. Increasing the minimum

operating speeds to those suggested

would improve maneuver and stall

warning margins beyond accepted

levels. Moreover, use of the suggested

higher flaps extended minimum

operational speeds would significantly

increase takeoff and landing field length

requirements, and unnecessarily

adversely affect the operating economics

of the airplane. However, under the

provisions of paragraph (c) of the final

rule, the FAA may consider requests for

approval of an alternative method of

compliance if sufficient data are

submitted to substantiate that such a

design change would provide an

acceptable level of safety.

The FAA concurs that the

recommended approach speeds for

operations in non-icing conditions are

not clearly defined in the current FAAapproved AFM. Consequently, the final

rule has been revised to include the

following information in the Approach

Checklist for Operation in Non-icing

Conditions: ‘‘Minimum Airspeed * * *

Appropriate to Flap Position. Gear Up/

Flaps 0, Minimum Recommended

Airspeed 150 KIAS. Gear Up/Flaps 15,

Minimum Recommended Airspeed 130

KIAS.’’ The requirements of the final

rule to increase approach speeds by 10

KIAS following flight in icing

conditions would, therefore, give

minimum approach speeds of 160 KIAS

and 140 KIAS for flaps 0 and 15,

respectively.

Incorporation of AFM Changes Into

Operators Manuals

Several commenters expressed

concern that the NPRM does not specify
Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations 66519

how the changes to the Normal

Procedures Section of the FAAapproved AFM will be implemented in

operator flight manuals and training

programs. This concern stems from the

fact that although EMBRAER issued

revision number 43 to the Normal

Procedures Section of its AFM in April

1996 to require activating the de-ice

boots ‘‘at the first sign of ice formation,’’

this new icing procedure has not yet

been implemented by several operators.

The FAA acknowledges that the final

rule does not specify how changes to the

Normal Procedures Section of the AFM

should be implemented in operator

flight manuals and training programs.

FAA Order 8400.10 recognizes that

operators may rewrite these AFM

procedures to tailor them to the

operators’ operation and to make them

more suitable for flightcrew use in

operation under parts 121 and 135 of

the Federal Aviation Regulations (14

CFR parts 121 and 135). However, the

FAA has chartered a team to review the

process being used to transfer

information in the manufacturer’s

flightcrew operating documents,

including AFM’s, to operators’

documents. The team will make

recommendations to revise the current

process, which could lead to a higher

level of safety. However, this issue is

beyond the scope of this rulemaking,

and no change has been made to the

final rule.

Cost Impact Information

Two commenters state that the cost of

retrofit will be substantially higher than

the estimated cost in the NPRM if

aircraft down time and canceled/

rescheduled equipment are considered.

One commenter requests an

explanation as to why a complete costbenefit analysis is unnecessary and

redundant. This commenter states that

the explanation given in the NPRM

relates to FAA’s position not to consider

additional costs of accomplishment of

the AD after a determination has been

made by the FAA that an unsafe

condition exists in a product.

Nevertheless, the commenter believes a

cost-benefit analysis should be used to

determine if a rule should be adopted in

the first place.

The FAA acknowledges the concerns

of the commenters of the cost of retrofit

required by this final rule. The FAA

recognizes that, in accomplishing the

requirements of any AD, operators may

incur other costs in addition to the

‘‘direct’’ costs that are estimated in the

cost impact. However, the FAA makes

every effort to consider all other costs

(such as downtime and canceled/

rescheduled equipment, etc.) to

operators in establishing the terms of

compliance in a AD. For example, the

FAA generally establishes AD

compliance times that coincide with

most operators’ maintenance schedules,

unless safety considerations dictate

more urgent corrective action. The FAA

also frequently revises AD’s when

commenters identify less costly

alternatives to address the unsafe

condition.

Finally, since the issuance of the

NPRM, EMBRAER has issued Service

Bulletin No. 120–30–0027, dated May 9,

1997, which describes procedures for

installation of an ice detector that will

enable the flightcrew to more accurately

determine the need to activate the ice

protection systems on the airplane and

to take appropriate action. The service

bulletin includes specific costs for the

installation of the ice detector. Those

figures have enabled the FAA to provide

a more realistic estimate in the cost

impact section of the final rule.

The FAA does not concur that further

discussion is necessary to explain why

a complete cost-benefit analysis is

unnecessary and redundant, since those

reasons were stated in the NPRM.

Further, the FAA does not concur that

a cost-benefit analysis should be used to

determine if a rule should be adopted in

the first place. Once an unsafe condition

is identified, as in this case, it must be

corrected regardless of cost. When the

FAA has determined what actions are

necessary to correct an unsafe

condition, the FAA is obligated to

require that those actions be

accomplished. This obligation arises

from the statutory requirement that the

FAA, not aircraft operators, determines

the minimum required safety standards

for civil aircraft. Therefore, it would be

inappropriate in issuing AD’s for the

FAA to engage in the same kind of

balancing of costs and benefits as when

it is considering regulations to improve

an already high level of safety. If an

operator has an alternative method of

compliance that would ease the

economic burden for the operator, as

well as provide an acceptable level of

safety, the operator may request

approval of that alternative method of

compliance, as provided by paragraph

(c) of the final rule.

Conclusion

After careful review of the available

data, including the comments noted

above, the FAA has determined that air

safety and the public interest require the

adoption of the rule with the changes

previously described. The FAA has

determined that these changes will

neither increase the economic burden

on any operator nor increase the scope

of the AD.

Cost Impact

There are approximately 282

EMBRAER Model EMB–120 series

airplanes of the affected design in the

worldwide fleet. The FAA estimates that

220 airplanes of U.S. registry will be

affected by this AD.

The FAA estimates that it will take

approximately 1 work hour per airplane

to accomplish the AFM revisions, and

that the average labor rate is $60 per

work hour. Based on these figures, the

cost impact of the AD on U.S. operators

is estimated to be $13,200, or $60 per

airplane.

The FAA estimates that it will take

approximately 47 work hours per

airplane to accomplish the proposed

installation, and that the average labor

rate is $60 per work hour. Required

parts will cost approximately $13,054

per airplane. Based on these figures, the

cost impact of the proposed AD on U.S.

operators is estimated to be $3,492,280,

or $15,874 per airplane.

The cost impact figure discussed

above is based on assumptions that no

operator has yet accomplished any of

the requirements of this AD action, and

that no operator would accomplish

those actions in the future if this AD

were not adopted.

Regulatory Impact

The regulations adopted herein will

not have substantial direct effects on the

States, on the relationship between the

national government and the States, or

on the distribution of power and

responsibilities among the various

levels of government. Therefore, in

accordance with Executive Order 12612,

it is determined that this final rule does

not have sufficient federalism

implications to warrant the preparation

of a Federalism Assessment.

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)

will not have a significant economic

impact, positive or negative, on a

substantial number of small entities

under the criteria of the Regulatory

Flexibility Act. A final evaluation has

been prepared for this action and it is

contained in the Rules Docket. A copy

of it may be obtained from the Rules

Docket at the location provided under

the caption ADDRESSES.
66520 Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations

List of Subjects in 14 CFR Part 39

Air transportation, Aircraft, Aviation

safety, Incorporation by reference,

Safety.

Adoption of the Amendment

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the Federal Aviation

Administration amends part 39 of the

Federal Aviation Regulations (14 CFR

part 39) as follows:

PART 39—AIRWORTHINESS

DIRECTIVES

1. The authority citation for part 39

continues to read as follows:

Authority: 49 U.S.C. 106(g), 40113, 44701.

§ 39.13 [Amended]

2. Section 39.13 is amended by

adding the following new airworthiness

directive:

97–26–06 Empresa Brasileira de

Aeronautica, S.A., (EMBRAER):

Amendment 39–10249. Docket 97–NM–

46–AD.

Applicability: All Model EMB–120 series

airplanes, certificated in any category.

Note 1: This AD applies to each airplane

identified in the preceding applicability

provision, regardless of whether it has been

otherwise modified, altered, or repaired in

the area subject to the requirements of this

AD. For airplanes that have been modified,

altered, or repaired so that the performance

of the requirements of this AD is affected, the

owner/operator must request approval for an

alternative method of compliance in

accordance with paragraph (c) of this AD.

The request should include an assessment of

the effect of the modification, alteration, or

repair on the unsafe condition addressed by

this AD; and, if the unsafe condition has not

been eliminated, the request should include

specific proposed actions to address it.

Compliance: Required as indicated, unless

accomplished previously.

To ensure that the flightcrew is able to

recognize the formation of significant ice

accretion, which could result in reduced

controllability of the airplane in normal icing

conditions, accomplish the following:

(a) Within 30 days after the effective date

of this AD, accomplish paragraphs (a)(1) and

(a)(2) of this AD.

(1) Revise the Limitations Section of the

FAA-approved Airplane Flight Manual

(AFM) to include the following requirements

for activation of the ice protection systems.

This may be accomplished by inserting a

copy of this AD in the AFM.

‘‘TURN ON ICE PROTECTION SYSTEM

and IGNITION SWITCHES AS FOLLOWS:

• AOA, TAT, SLIP, ENGINE AIR INLET,

and IGNITION SWITCHES:

—When atmospheric or ground icing

conditions exist.

• PROPELLER:

—When atmospheric or ground icing

conditions exist, OR

—At the first sign of ice formation anywhere

on the aircraft.

WING and TAIL LEADING EDGES, and

WINDSHIELD:

—At the first sign of ice formation anywhere

on the aircraft.

Note: On takeoff, delay activation of the

wing and tail leading edge de-ice systems

until reaching the final segment speed.

Note: Atmospheric icing conditions exist

when:

—Indicated Outside Air Temperature (OAT)

during ground operations or Total Air

Temperature (TAT) in flight is 10 degrees

C or below; and

—Visible moisture in any form is present

(such as clouds, fog with visibility of one

mile or less, rain, snow, sleet, or ice

crystals).

Note: Ground icing conditions exist when:

—Indicated OAT during ground operations is

10 degrees C or below; and

—Surface snow, standing water, or slush is

present on the ramps, taxiways, or

runways.

Note: For Operation in Atmospheric Icing

Conditions:

—Follow the procedures in the Normal

Procedures Section under Operation in

Icing Conditions.’’

(2) Revise the Normal Procedures Section

of the FAA-approved Airplane Flight Manual

(AFM) to include the following additional

and revised information regarding operation

in icing conditions. This may be

accomplished by inserting a copy of this AD

in the AFM.

‘‘Under DAILY CHECKS of the Ice

Protection System, add the following:

The following tests must be performed

prior to the first flight of the day for which

known or forecast icing conditions are

anticipated.

Ice Detector System TEST Button (if

installed)..........................................PRESS

Check normal test sequence.

Under APPROACH Checklist, add the

following:

Minimum Airspeed...........APPROPRIATE TO

FLAP POSITION (See Table Below)

Gear/Flap Minimum Recommended

Airspeed

UP/0° .......... 150 KIAS

UP/15° ........ 130 KIAS

Under OPERATION IN ICING

CONDITIONS for FLYING INTO ICING

CONDITION, replace the current AFM

section information for normal icing

conditions with the following:

—During flight, monitoring for icing

conditions should start whenever the

indicated outside air temperature is near or

below freezing or when operating into icing

conditions, as specified in the Limitations

Section of this manual.

—When operating in icing conditions, the

front windwhield corners (unheated areas),

propeller spinners, and wing leading edges

will provide good visual cues of ice

accretion.

—For airplanes equipped with an ice

between system, icing conditions will also

be indicated by the illumination of the ICE

CONDITION light on the multiple alarm

panel.

—When atmospheric or ground icing

conditions exist, proceed as follows:

AOA, TAT, SLIP, and ENGINE AIR

INLET ....................................................ON

IGNITION Switches ....................................ON

AIRSPEED (Flaps and Gear UP) .......160 KIAS

MINIMUM

—When atmospheric or ground icing

conditions exist, OR

—At the first sing of ice formation any where

on the aircraft, proceed as follows:

PROPELLER Deicing Switch.......................ON

Select NORM mode if indicated OAT is

above ¥10° C (14° F) or COLD mode if

indicated OAT is below ¥10° C (14° F).

—At the first sign of ice formation anywhere

on the aircraft, proceed as follows:

WINDSHIELD ..............................................ON

WING and TAIL LEADING EDGE...............ON

Visually evaluate the severity of the ice

encounter and the rate of accretion and select

light or heavy mode (1 minute or 3 minute

cycle) based on this evaluation.

Note: On takeoff, delay activation of the

wing and tail leading edge de-ice systems

until reaching the final segment speed.

Note: The minimum NH required for

proper operation of the pneumatic deicing

system is 80%. At lower NH values, the

pneumatic deicing system may not totally

inflate, and the associated failure lights on

the overhead panel may illuminate. If this

occurs, increase NH.

Holding configuration:

Landing Gear Lever......................................UP

Flap Selector Lever ......................................UP

Np ............................................85% MINIMUM

Increase Np as required to eliminate

propeller vibrations.

Approach and Landing procedure:

Increase approach and landing speeds,

according to the following flap settings, until

landing is assured. Reduce airspeed to cross

runway threshold (50 ft) at VREF.

Flaps 15—Increase Speed by 10 KIAS

(130+10)

Flaps 25—Increase Speed by 10 KIAS

(VREF25+10)

Flaps 45—Increase Speed by 5 KIAS

(VREF45+5)

Go-Around procedure:

Reduce values from Maximum Landing

Weight Approach Climb Limited charts by:

1500 lbs. for PW 118 Engines

1544 lbs. for PW 118A and 118B Engines

Flaps 15—Increase approach climb speed by

10 KIAS (V2+10); Decrease approach

climb gradient by:

3.0% for PW 118 Engines

2.9% for PW 118A and 118B Engines

Flaps 25—Increase landing climb speed by

10 KIAS (VREF25+10)

Flaps 45—Increase landing climb speed by 5

KIAS (VREF+5)

CAUTION: The ice protection systems must

be turned on immediately (except leading

edge de-icers during takeoff) when the ICE

CONDITION light illuminates on the

multiple alarm panel or when any ice

accretion is detected by visual observation or

other cues.
Federal Register / Vol. 62, No. 244 / Friday, December 19, 1997 / Rules and Regulations 66521

CAUTION: Do not interrupt the automatic

sequence of operation of the leading edge deice boots once it is turned ON. The system

should be turned OFF only after leaving the

icing conditions and after the protected

surfaces of the wing are free of ice.

(b) Within 10 months after the effective

date of this AD, install an ice detector in

accordance with EMBRAER Service Bulletin

No.: 120–30–0027, dated May 9, 1997.

(c) An alternative method of compliance or

adjustment of the compliance time that

provides an acceptable level of safety may be

used if approved by the Manager, Atlanta

ACO. Operators shall submit their requests

through an appropriate FAA Principal

Operations Inspector, who may add

comments and then send it to the Manager,

Atlanta ACO.

Note 2: Information concerning the

existence of approved alternative methods of

compliance with this AD, if any, may be

obtained from the Atlanta ACO.

(d) 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.

(e) The installation of the ice detector shall

be done in accordance with EMBRAER

Service Bulletin No. 120–30–0027, dated

May 9, 1997. This incorporation by reference

was approved by the Director of the Federal

Register in accordance with 5 U.S.C. 552(a)

and 1 CFR part 51. Copies may be obtained

from EMBRAER, Empresa Brasileira De

Aeronautica S/A, Sao Jose Dos Campos,

Brazil. Copies may be inspected at the FAA,

Transport Airplane Directorate, 1601 Lind

Avenue, SW., Renton, Washington; or at the

Office of the Federal Register, 800 North

Capitol Street, NW., suite 700, Washington,

DC.

(f) This amendment becomes effective on

January 23, 1998.

Issued in Renton, Washington, on

December 11, 1997.

Gilbert L. Thompson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service.

[FR Doc. 97–33000 Filed 12–18–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF THE TREASURY

Customs Service

19 CFR Part 4

[T.D. 98–3]

RIN 1515—AC27

Addition of Hong Kong to the List of

Nations Entitled to Special Tonnage

Tax Exemption

AGENCY: U.S. Customs Service,

Department of the Treasury.

ACTION: Final rule.

SUMMARY: Pursuant to information

provided by the Department of State, the

United States Customs Service has

found that Hong Kong does not impose

or levy any discriminating duties of

tonnage or imposts upon vessels wholly

belonging to citizens of the United

States, or upon the produce,

manufactures, or merchandise imported

in these vessels from the United States

or any foreign country and that,

accordingly, vessels of Hong Kong are

exempt from the payment of special

tonnage taxes and light money in ports

of the United States. This document

amends the Customs Regulations by

adding Hong Kong to the list of nations

whose vessels are exempt from the

payment of any higher tonnage duties

than are applicable to vessels of the

United States and from the payment of

light money.

EFFECTIVE DATE: The amendment to the

19 CFR 4.22 is effective on December

19, 1997. The exemption from special

tonnage tax and light money for vessels

registered in Hong Kong became

effective on July 1, 1997.

FOR FURTHER INFORMATION CONTACT:

Craig Clark, Entry and Carrier Rulings

Branch (202) 927–2320.

SUPPLEMENTARY INFORMATION:

Background

Generally, the United States imposes

regular and special tonnage taxes, and a

duty of a specified amount per ton

denominated ‘‘light money’’, on all

foreign vessels which enter United

States ports (46 U.S.C. App. 121 and

128). Vessels of a foreign nation,

however, may be exempted from the

payment of such special tonnage taxes

and light money upon presentation of

satisfactory proof that no discriminatory

duties of tonnage or impost are imposed

by that foreign nation on United States

vessels or their cargoes (46 U.S.C. App.

141). The list of nations whose vessels

have been found to be reciprocally

exempt from the payment of any higher

tonnage duties than are applicable to

vessels of the United States and from

the payment of light money is found at

§ 4.22, Customs Regulations (19 CFR

4.22). Nations granted these commercial

privileges that subsequently impose

discriminatory duties are subject to

retaliatory suspension of the

commercial privileges (46 U.S.C. App.

141 and 142).

Treatment of Hong Kong

On July 1, 1997, Hong Kong became

a Special Administrative Region of the

People’s Republic of China. Before that

date, vessels from Hong Kong had an

exemption from special tonnage tax by

virtue of Hong Kong’s status as a British

colony.

The Department of State has

requested that Customs add Hong Kong

to the list of nations under § 4.22 in

order that vessels from Hong Kong

receive the same treatment as they did

prior to July 1, 1997. In addition, the

Department of State has submitted

information regarding the absence of

discriminatory duties of tonnage or

impost imposed on U.S. vessels in the

ports of Hong Kong.

The Department of State’s request is

consistent with the terms of section 2 of

the Act of October 5, 1992, referred to

as the United States-Hong Kong Policy

Act (Pub. L. 102–383, 106 Stat. 1448)

codified in title 22, United States Code,

section 5701, et seq., which embodies

the policy of the United States

applicable to dealing with Hong Kong

following reversion, including trade and

commerce matters. That law

demonstrates that dealings with Hong

Kong after June 30, 1997, are to be

conducted without change until and

unless the Administration (the

President) makes a determination that

different treatment is warranted.

Finding

Based on the request and information

submitted by the Department of State,

and based on 22 U.S.C. 5701, et seq., in

order that vessels from Hong Kong

remain exempt from the payment of

special tonnage tax following reversion,

the Customs Service has determined

that Hong Kong should be added to the

list of nations contained in 19 CFR 4.22,

effective July 1, 1997. The Customs

Regulations are amended accordingly.

Inapplicability of Public Notice and

Delayed Effective Date Requirements,

the Regulatory Flexibility Act, and

Executive Order 12866

Because this amendment merely

implements a statutory requirement and

confers a benefit upon the public,

pursuant to 5 U.S.C. 553(b)(B), notice

and public procedure are unnecessary;

further, for the same reasons, good cause

exists for dispensing with a delayed

effective date under 5 U.S.C. 553(d)(1)

and (3). Since this document is not

subject to the notice and public

procedure requirements of 5 U.S.C. 553,

it is not subject to the provisions of the

Regulatory Flexibility Act (5 U.S.C. 601

et seq.). Furthermore, this amendment

does not meet the criteria for a

‘‘significant regulatory action’’ as

specified in Executive Order 12866.

List of Subjects in 19 CFR Part 4

Cargo vessels, Customs duties and

inspection, Maritime carriers, Vessels.