This section of the FEDERAL REGISTER

contains regulatory documents having general

applicability and legal effect, most of which

are keyed to and codified in the Code of

Federal Regulations, which is published under

50 titles pursuant to 44 U.S.C. 1510.

The Code of Federal Regulations is sold by

the Superintendent of Documents. Prices of

new books are listed in the first FEDERAL

REGISTER issue of each week.

Rules and Regulations Federal Register

45523

Vol. 62, No. 167

Thursday, August 28, 1997

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM–134; Special Conditions

No. 25–ANM–131]

Special Conditions: Empresa Brasileira

de Aeronautica S.A., (EMBRAER)

Model EMB–145 Airplane; Thrust

Reverser Systems

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final special conditions.

SUMMARY: These special conditions are

for the Empresa Brasileira de

Aeronautica S.A., (EMBRAER) Model

EMB–145 airplane. This airplane will

have a novel or unusual design feature

associated with thrust reversers as

optional equipment. These special

conditions contain the additional safety

standards which the Administrator

considers necessary to establish a level

of safety equivalent to that established

by the airworthiness standards of part

25 of the Federal Aviation Regulations

(FAR).

EFFECTIVE DATE: September 29, 1997.

FOR FURTHER INFORMATION CONTACT:

Colin Fender, FAA, Flight Test and

Systems Branch of the Transport

Standards Staff, ANM–111, Transport

Airplane Directorate, Aircraft

Certification Service, 1601 Lind Avenue

SW, Renton, Washington 98055–4056;

telephone 425–227–2191.

SUPPLEMENTARY INFORMATION:

Background

Embraer first made application for a

U.S. Type Certificate for the Model

EMB–145 on August 30, 1989, to the

FAA Atlanta Aircraft Certification

Office through the Brazilian Centro

Te ́cnico Aeroespacial (CTA). On June 2,

1992, Embraer filed for an extension of

that application. The EMB–145 is a 50

passenger, pressurized, low-winged,

‘‘T’’ tailed, transport category airplane

with retractable tricycle type landing

gear. The airplane is powered by two

Allison Model AE3007A high bypass

ratio turbofan engines mounted on the

aft fuselage, which are controlled by a

Full Authority Digital Engine Control

(FADEC). The cockpit will include a

complete set of Electronic Flight

Instrumentation and Engine Indication

and Crew Alerting Systems (EFIS and

EICAS).

Embraer has proposed to certificate

and market the EMB–145 with thrust

reversers as optional equipment. Thrust

reversers have been shown to play a

significant role in reducing acceleratestop distances on wet and contaminated

runways and have contributed to the

transport category airplane fleet’s

accelerate-stop safety record.

The establishment of the transport

category airplane safety record, with

regard to accelerate-stop and landing

overruns, is tied to the availability of

auxiliary braking means that are

independent of wheel-brake, tire, and

runway surface interaction. On early

transport category airplanes with

propellers driven by reciprocating

engines or turbine powerplants,

auxiliary braking was provided by

commanding the propellers to a reverse

pitch position, causing a deceleration,

rather than acceleration, of air through

the propeller disk. Due to the large

diameter of the propellers, this was

quite an effective braking means.

Though these early transports did not

have the high operating speeds of

today’s jet fleet, they also did not benefit

from the sophisticated wheel-brake

antiskid systems available today. As

runway friction conditions degrade to

those associated with a surface covered

by ice, even today’s antiskid systems

will provide little in the way of stopping

force. As runway friction conditions

degrade, the braking contribution of

reverse pitch systems increases

considerably.

As the first generation turbojetpowered transport category airplanes

went into service in the latter half of the

1950s, thrust reverser systems were

developed to provide this same type of

auxiliary braking as reverse pitch

propellers by reversing the engine

exhaust flow. As powerplant technology

evolved and low bypass ratio turbofan

engines entered commercial service in

the early 1960’s, thrust reversers were

developed to reverse both the fan and

core exhaust flows, thus maintaining the

availability of auxiliary braking. With

the advent of large high bypass ratio

turbofan engines in the late 1960s, many

thrust reverser systems reversed the fan

exhaust flow only, which provided a

substantial auxiliary braking effect due

to the majority of the total inlet flow

going through the fan section.

Numerous test programs, by both

research organizations and aerospace

manufacturers, have substantiated the

increased stopping benefit provided by

thrust reversers as runway surface

friction conditions deteriorate.

The vast majority of jet-powered

transport category airplanes in service

have been of the large, passenger

carrying variety. Research shows that

with the exception of a very limited

number of airplane types, some of

which had considerably slower takeoff

and landing speeds than their

counterparts, all these large, passenger

carrying, turbojet/turbofan-powered

transports included thrust reverser

systems as part of their basic design

(i.e., as standard equipment). The last

such aircraft certified without thrust

reversers as part of the basic design was

the British Aerospace 146 (BAe 146) in

1983. When the sheer numerical

majority of these large transports is

combined with their high-use operating

environment, often requiring takeoffs

and landings to be made on slippery

runway surfaces, it is clear that thrust

reversers must have played a role in

establishing their excellent safety

record.

It should also be noted that as the

number of small transport category

airplanes in service has increased,

notably corporate jets and regional

airliners, there has been an increasing

tendency for these airplanes to be

equipped with some type of thrust

reversing system. Nearly all the regional

airliners are turbopropeller-powered

with reverse pitch capability, and an

increasing number of corporate jets

include thrust reversers as standard

equipment.

The accelerate-stop and landing

distances presented in the FAA

approved Airplane Flight Manual

(AFM) are determined from

measurements of the various influential

parameters taken during certification

flight tests. These flight tests are
45524 Federal Register / Vol. 62, No. 167 / Thursday, August 28, 1997 / Rules and Regulations

accomplished by FAA test pilots (or

manufacturers’ Designated Engineering

Representative (DER) test pilots) under

controlled conditions on dry runways.

In the operational environment, even on

dry runways, the ability of an airplane

to match the AFM accelerate-stop

performance is based on many factors,

including the correct and timely

execution of procedures by the pilot and

maximum stopping performance being

available from the wheel braking

system. As runway surface conditions

degrade to wet, contaminated, or icy,

the accompanying reduction in

available friction will result in an

increase in stopping distances, causing

the wet runway accelerate-stop

distances to exceed the dry runway

accelerate-stop distances published in

the AFM. Obviously, if the takeoff is

runway length-limited as determined

from the dry runway AFM acceleratestop distances, and the runway surface

is anything but dry, the probability for

an overrun accident is increased

significantly. (This increased risk factor

is acknowledged for the landing

scenario in part 121, the operating rules

for air carriers and commercial

operators of large aircraft, which

requires an increase in the landing field

length required for landings on wet

runways.)

In the operating conditions described

above, any additional braking means,

such as thrust reversers, will be

beneficial. This is particularly true since

the braking contribution of reverse

thrust increases as runway surface

friction decreases. This inverse

relationship between reverse thrust

braking contribution and runway

surface friction is further enhanced as

ground speed increases.

Since 1990 the Transport Airplane

Directorate (TAD) has been developing

new part 25 accelerate-stop criteria that

includes accountability for the

degradation in stopping force due to wet

runway surfaces. Test results obtained

from several research organizations

showed a fixed stopping distance factor

of two, relative to dry runway stopping

distances, to be representative of what

could be expected in normal operations.

The proposed accelerate-stop standards,

published as Notice of Proposed

Rulemaking (NPRM) 93–8, assumed a

similar degradation in braking by

prescribing a wet/dry braking coefficient

of friction ratio of one-half (i.e., μ WET

= 0.5 μ DRY) as the primary basis for

calculating wet runway accelerate-stop

distances. An integral part of the

proposed wet runway accelerate-stop

rule is credit for the amount of reverse

thrust available (provided certain

reliability and controllability criteria are

met).

The accelerate-stop certification basis

for the EMB–145 is § 25.109, as

amended by Amendment 25–42,

effective March 1, 1978. Thrust

reversing systems are not required by

the FAR and, when installed, no

performance credit is granted for their

availability in the dry runway

accelerate-stop distances required by

§ 25.109, as amended by Amendment

25–42, effective March 1, 1978.

However, the vast majority of transport

category airplanes in service at the time

the regulatory changes of Amendment

25–42 were promulgated were equipped

with thrust reversers. Consequently, the

certification of transport category

airplanes intended to be operated in

Part 121-type commercial service

without thrust reversers was not

envisaged at the time Amendment 25–

42 was promulgated.

In consideration of the intended

operation of the EMB–145, the FAA

considers the non-inclusion of thrust

reversers into the basic airplane to be an

unusual design feature that is not

adequately addressed by the

airworthiness regulations of part 25, and

therefore proposes to apply special

conditions to the EMB–145 in

accordance with § 21.16. In accordance

with the preamble material to

Amendment 25–54 (page 274),

addressing the definition of a novel or

unusual design feature (as used in

§ 21.16), the non-inclusion of thrust

reversers in the basic EMB–145 design

can be considered a ‘‘novel or unusual

design feature’’ since such designs were

not envisaged at the time the current

airworthiness standard (i.e., § 25.109,

Amendment 25–42) was developed.

This application requires the

development of requirements not fully

addressed by part 25 nor by any

published FAA guidance.

These special conditions provide all

the necessary requirements to determine

acceptability of the EMB–145 without

the incorporation of thrust reversers.

Type Certification Basis

Under the provisions of 14 CFR 21.17,

Empresa Brasileira de Aeronautica S.A.

must show that the Model EMB–145

meets the applicable provisions of part

25, as amended by Amendments 25–1

through 25–84.

In addition to the applicable

airworthiness regulations and special

conditions, the Model EMB–145 must

comply with the fuel vent and exhaust

emission requirements of 14 CFR part

34 and the noise certification

requirements of 14 CFR part 36, and the

FAA must make a finding of regulatory

adequacy pursuant to section 611 of

Public Law 92–574, the ‘‘Noise Control

Act of 1972.’’

If the Administrator finds that the

applicable airworthiness regulations

(i.e., part 25 as amended) do not contain

adequate or appropriate safety standards

for the Model EMB–145 because of a

novel or unusual design feature, special

conditions are prescribed under the

provisions of § 21.16.

Special conditions, as appropriate, are

issued in accordance with § 11.49 after

public notice, as required by §§ 11.28

and 11.29(b), and become part of the

type certification basis in accordance

with § 21.17(a)(2).

Special conditions are initially

applicable to the model for which they

are issued. Should the type certificate

for that model be amended later to

include any other model that

incorporates the same novel or unusual

design feature, these special conditions

would also apply to the other model

under the provisions of § 21.101(a)(1).

Novel or Unusual Design Features

The Model EMB–145 will have an

unusual design feature which is the lack

of incorporation of thrust reversers as

standard equipment.

Discussion of Comments

Notice of Proposed Special

Conditions No. SC–96–7–NM for the

Empresa Brasileira de Aeronautica S.A.,

(EMBRAER) Model EMB–145, was

published in the Federal Register on

November 18, 1996. Three commenters

submitted comments.

All commenters state the special

conditions are inappropriate since

thrust reversers are not required for part

25 certification and part 25 airplanes

not equipped with thrust reversers have

exhibited the same level of safety as

those with thrust reversers. The FAA

does not contest the fact that part 25

does not require thrust reversers. With

regard to the level of safety issue, it is

obvious that the additional braking

provided by reverse thrust will always

improve safety, and the amount of that

improvement will increase with

decreasing runway surface friction. The

only accelerate-stop performance

information required to be in the

Airplane Flight Manual (AFM) by the

current part 25 airworthiness

regulations is based on a dry runway

surface; these dry runway acceleratestop distances may (and will) be used

with no adjustments for takeoffs made

on wet and contaminated runways. This

could be of critical importance for an

airplane the size of the EMB–145, which

in all likelihood will see a sizable

number of operations on relatively short
Federal Register / Vol. 62, No. 167 / Thursday, August 28, 1997 / Rules and Regulations 45525

runways, thus increasing the probability

of its being dry runway takeoff or

landing field length-limited.

One commenter states that the main

consideration of the special conditions

is that the non-inclusion of thrust

reversers is classified as an unusual

design feature because the EMB–145 is

intended for operation in part 121-type

commercial service. Consequently, the

commenter states the special conditions

are not appropriate under part 25 since

the certification basis is independent of

the rules an airplane might be operated

under. The FAA does not agree with the

commenter’s statement. The overall

operational safety of an airplane is as

much the concern of the Aircraft

Certification Service of the FAA as it is

the Flight Standards Service,

particularly where aircraft performance

is a consideration since it is the Aircraft

Certification Service personnel who

witness the flight testing and approve

the resulting Airplane Flight Manual

performance that scheduled operations

will be based on.

Similarly, another commenter states

that if performance credit is of

established benefit in part 121-type

commercial operations, the appropriate

rule to require thrust reversers would be

under part 121 and not the certification

rules (i.e., part 25). The FAA questions

the use of the term ‘‘performance credit’’

since no performance credit has been

given in the past, as discussed in the

preceding paragraph. The FAA

understands this comment to mean if

thrust reversers have provided benefits

in part 121-type operations, then any

rule to require their installation should

be proposed under part 121. The FAA

disagrees with this comment. The FAA’s

job is to ensure the safety of the

traveling public; whether that is done

through the Aircraft Certification

Service or the Flight Standards Service

is irrelevant in this case. As discussed

in the notice of proposed special

conditions, the thrust reverser issue is

addressed in this context because the

FAA has found that Embraer’s type

certificate application presents a novel

or unusual design feature for which the

applicable airworthiness standards do

not provide adequate safety standards.

In accordance with 14 CFR § 21.16,

special conditions are the appropriate

mechanism for dealing with such issues.

One commenter states that if the FAA

considers the increased stopping benefit

provided by thrust reversers as

substantiation (sic) for requiring their

installation, then performance credit

should be granted for their use. The

FAA has for many years gone on record

as being opposed to granting general

performance credit for the use of thrust

reversers. One of the primary reasons for

this position is that thrust reversers

provided some compensation for the

minimal amount of conservatism

assumed in determining the acceleratestop distances that takeoffs will be

predicated on rejected takeoff accident

data indicate that pilots do not always

recognize and respond to a failure

condition at or near V1 in the time

period assumed in calculating the AFM

accelerate-stop distances. The FAA has

proposed to grant performance credit for

thrust reversers in the determination of

accelerate-stop distances on wet

runways, provided the stopping

distances are based on the associated

reduced wheel-brake stopping force

available and certain reliability and

controllability criteria are met.

One commenter notes that the

proposed special conditions do not

address the Master Minimum

Equipment List (MMEL) allowance for

airplanes to have thrust reversers

rendered inoperative, and that the FAA

did not consider the economic

implications of this issue. The FAA

does not consider this to be a relevant

argument against requiring the

installation of thrust reversers on the

EMB–145. The MMEL allowance

referred to by the commenter is

classified as Level C which, among

other things, places a 10-day limitation

on the thrust reversers being

inoperative. The 10-day limitation is, in

part, based on the probability of

occurrence of a situation in which the

additional braking force provided by

reverse thrust would be beneficial.

One commenter states that the

inclusion of a proposed rule (i.e., NPRM

93–8) as a certification requirement was

not appropriate. A related comment

from another commenter noted that

FAA’s Aircraft Certification Service

management has stated the FAA would

not invoke unadopted regulations or

policy on active certification programs.

The FAA is not mandating compliance

with the criteria of NPRM 93–8 as a

certification requirement. Embraer has

the option of installing thrust reversers

on the airplane and determining

accelerate-stop distances in accordance

with part 25 at the amendment level

described in the type certification basis

for the EMB–145. It should also be

noted that in ongoing certification

programs, the FAA Transport Airplane

Directorate routinely considers

proposed rules as showing an

equivalent level of safety to existing part

25 regulations.

One commenter also states that NPRM

93–8 is not harmonized with the

European Joint Aviation Authorities

(JAA) requirements. This statement is

incorrect. The criteria of NPRM 93–8

was developed in conjunction with the

JAA; requirements identical to those of

NPRM 93–8 can be found in the

equivalent AAA Notice of Proposed

Amendment.

One commenter requests the FAA

submit this major change in certification

philosophy to the appropriate

regulatory/industry forum. The FAA

discussed the philosophy embodied in

Notice No. SC–96–7–NM with flight test

specialists from several foreign civil

airworthiness authorities during its

development. The FAA is within its

legal bounds by treating airplanes on a

case-by-case basis with special

conditions in accordance with § 21.16.

The FAA does not believe it is necessary

to submit the certification philosophy

embodied in Notice No. SC–96–7–NM

to a regulatory/industry forum since the

wet runway accelerate-stop criteria in

NPRM 93–8, which gives performance

credit for available reverse thrust on wet

runways, will encourage manufacturers

to incorporate thrust reversers as part of

the basic design of their airplanes.

One commenter states that the FAA’s

contention that thrust reversers have

played a significant role in the safety

record of transport category airplanes is

not supported by any form of factual

information or data. The FAA disputes

this commenter’s position. A significant

amount of testing has been conducted

over the last 40 years that has repeatedly

proven the increased benefit of reverse

thrust as the runway surface condition

deteriorates in terms of available wheelbraking force. It is obviously difficult to

point at a particular rejected takeoff as

an example since any successful field

length-limited RTO that may have

occurred on a wet or contaminated

runway, whose takeoff weight was

limited by a dry runway accelerate-stop

distance, would not have been recorded.

However, it stands to reason that the

probability of such a case occurring

would be very low without the

additional braking force contribution

provided by thrust reversers.

As discussed above, these special

conditions are applicable to the EMB–

145. Should Empresa Brasileira de

Aeronautica S.A. apply at a later date

for a change to the type certificate to

include another model incorporating the

same novel or unusual design feature,

the special conditions would apply to

that model as well under the provisions

of § 21.101(a)(1).

Conclusion: This action affects only

certain novel or unusual design features

on one model of airplane. It is not a rule

of general applicability, and it affects

only the manufacturer who applied to
45526 Federal Register / Vol. 62, No. 167 / Thursday, August 28, 1997 / Rules and Regulations

the FAA for approval of these features

on the airplane.

List of Subjects in 14 CFR Part 25

Aircraft, Aviation safety, Federal

Aviation Administration, Reporting and

recordkeeping requirements.

The authority citation for these

special conditions is as follows:

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

44702, 44704.

The Special Conditions

Accordingly, pursuant to the

authority delegated to me by the

Administrator, the following special

conditions are issued as part of the type

certification basis for the Empresa

Brasileira de Aeronautica S.A., Model

EMB–145 airplanes not equipped with

thrust reversers.

1. The effect of wet runway surfaces

on accelerate-stop distances for the

Model EMB–145 must be accounted for

in accordance with the criteria

contained in NPRM 93–8 and its

associated guidance.

2. Takeoff limitations for operation of

the EMB–145 on wet runway surfaces

must be predicated on the wet runway

accelerate-stop criteria contained in

NPRM 93–8.

Issued in Renton, Washington, on August

18, 1997.

Stewart R. Miller,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 97–22919 Filed 8–27–97; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 71

[Airspace Docket No. 93–AWA–16]

RIN 2120–AA66

Modification of Class D Airspace South

of Abbotsford, British Columbia (BC),

on the United States Side of the U.S./

Canadian Border, and the

Establishment of a Class C Airspace

Area in the Vicinity of Point Roberts,

Washington (WA)

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This action establishes a Class

C airspace area in the United States

(U.S.), southeast of Vancouver, BC, in

the vicinity of Point Roberts, WA. The

Vancouver Class C airspace area will

have a ceiling of 12,500 feet Mean Sea

Level (MSL), and a floor of 2,500 feet

MSL. In addition, this action extends

the existing Abbotsford, BC, Class D

airspace area west into airspace which

is currently Class E airspace, and lowers

the ceiling of the Class D airspace area

from 3,000 to 2,500 feet MSL in U.S.

airspace. The FAA is taking these

actions pursuant to a proposal by

Transport Canada, and to assist

Transport Canada in its efforts to reduce

the risk of midair collision, enhance

safety, and improve air traffic flows

within the Vancouver and Abbotsford,

BC, International Airport areas.

EFFECTIVE DATE: 0901 UTC, November 6,

1997.

FOR FURTHER INFORMATION CONTACT: Ken

McElroy, Airspace and Rules Division,

ATA–400, Office of Air Traffic Airspace

Management, Federal Aviation

Administration, 800 Independence

Avenue, SW., Washington, DC 20591;

telephone: (202) 267–8783.

SUPPLEMENTARY INFORMATION:

Background

In July 1994, Transport Canada

proposed to extend the Vancouver, BC,

Class C airspace area across the United

States/Canadian border into U.S.

airspace in the vicinity of the San Juan

Islands and Bellingham, WA. As

proposed, the Class C airspace area

would have extended from Abbotsford

Airport, across Bellingham Airport, to a

point south of San Juan Island.

Transport Canada’s proposal was part of

its overall airspace plan for the

Vancouver area, centering around efforts

to mitigate near mid-air collision

potential between instrument flight rule

(IFR) and unknown visual flight rule

(VFR) aircraft in U.S. airspace where

Canada provides air traffic services.

Class C airspace consists of controlled

airspace extending upward from the

surface or higher to specified altitudes

within which all aircraft are subject to

the operating rules and equipment

requirements specified in Federal

Aviation Regulations. Two-way radio

communication must be established

with the air traffic control (ATC) facility

providing ATC services prior to entry

and thereafter maintained while

operating within Class C airspace. The

standard Class C airspace area consists

of that airspace within 5 Nautical Miles

(NM) of the primary airport, extending

from the surface to an altitude of 4,000

feet above that airport’s elevation, and

that airspace between 5 and 10 NM from

the primary airport from 1,200 feet

above the surface to an altitude of 4,000

feet above that airport’s elevation.

Proposed deviations from this standard

have been necessary at some airports

because of adjacent regulatory airspace,

international boundaries, topography, or

unusual operational requirements.

The Class C airspace area proposed by

Transport Canada differed from most

other Class C airspace areas in that it

was to an extension of a foreign Class C

airspace area serving a primary airport

outside the U.S.; standard U.S. Class C

airspace configurations and dimensions

were therefore unsuitable.

Transport Canada’s proposal also

included a proposal to extend the

western boundary of the Abbotsford,

BC, Class D airspace area approximately

7 nautical miles (NM) west of its present

location, and to lower the ceiling of the

Class D airspace from 3,000 feet MSL to

2,500 feet MSL.

Class D airspace is, generally, that

airspace from the surface to 2,500 feet

above the airport elevation (charted in

MSL) surrounding those airports that

have an operational control tower. The

configuration of each Class D airspace

area is individually tailored and the

airspace will normally be designed to

contain any published instrument

approach procedures. Two-way radio

communication must be established

with the ATC facility providing ATC

services prior to entry and thereafter

maintained while operating in the Class

D airspace.

The Vancouver and Abbotsford

Airports are both international and

public-use airports located in Canada.

Passenger enplanements reported at

Vancouver in 1995 were 312,000, up

from 301,000 in 1994. This volume of

passenger enplanements and aircraft

operations meets the FAA criteria for

establishing a Class C airspace area to

enhance safety.

Public Meetings

As announced in the Federal Register

on March 22, 1995 (60 FR 15172), two

pre-NPRM airspace meetings were held

on May 9–10, 1995, in Friday Harbor

and Bellingham, WA. The purpose of

these meetings was to provide local

airspace users with an opportunity to

present input on the Transport Canada

proposal prior to initiating any

regulatory action. In the ensuing

comment period, which closed on July

10, 1995, over 300 comments were

received in overwhelming opposition to

the proposal. The majority of the

opposition centered around the

significant amount of airspace affected

by the original proposal. The original

proposal would have required the

reclassification of airspace in five

contiguous areas from Abbotsford

Airport, across Bellingham Airport, to a

point south of San Juan Island.

Subsequent meetings were held between