Federal Register / Vol. 62, No. 200 / Thursday, October 16, 1997 / Rules and Regulations 53737

lubrication, and adjustment during the

required inspection of the system.

7. Operating Limitations

(a) Operating limitations must be

prescribed to ensure proper operation of

the system within its deployment

envelope. A detailed discussion of the

system, including operation, limitations

and deployment envelope must be

included in the Airplane Flight Manual.

(b) The deployment envelope of the

GARD system must be possible at

speeds up to VO or higher.

(c) Operating limitations must be

prescribed for inspecting, repacking,

and replacing the parachute and

deployment mechanism at approved

intervals.

Issued in Kansas City, Missouri on

September 30, 1997.

Michael Gallagher,

Manager, Small Airplane Directorate Aircraft

Certification Service.

[FR Doc. 97–27504 Filed 10–15–97; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 25

[Docket No. NM–135; Special Conditions

No. 25–ANM–133]

Special Conditions: Boeing, Model

767–27C Airplanes, Airborne Warning

and Control System (AWACS)

Modification; Liquid Oxygen System

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final special conditions.

SUMMARY: These special conditions are

issued for Boeing Model 767–27C

airplanes modified by installation of an

Airborne Warning and Control System

(AWACS). These airplanes will be

equipped with an oxygen system

utilizing liquid oxygen (LOX). The

applicable regulations do not contain

adequate or appropriate safety standards

for the design and installation of oxygen

systems utilizing LOX for storage. These

standards are intended to ensure that

the design and installation of the liquid

oxygen system is such that a level of

safety equivalent to that established by

the airworthiness standards for

transport category airplanes is provided.

EFFECTIVE DATE: November 17, 1997.

FOR FURTHER INFORMATION CONTACT:

William Schroeder, FAA,

Standardization Branch, ANM–113,

Transport Airplane Directorate,

Airplane Certification Service, 1601

Lind Avenue SW, Renton, Washington

98055–4056; telephone (425) 227–2148.

SUPPLEMENTARY INFORMATION:

Background

On May 25, 1993, Boeing Commercial

Airplane Group—Wichita Division,

applied for a supplemental type

certificate (STC) to modify Boeing

Model 767–27C airplanes to an Airborne

Warning and Control System (AWACS)

configuration. The AWACS

modification includes installation of

equipment consoles, seats for console

operators, a liquid oxygen (LOX) system

(liquid oxygen converter, valves,

evaporating coils, lines, regulators,

indicators, fittings, etc.), and a radome

on the top of the airplane. Boeing will

modify the aft lower lobe with

hydraulics for the AWACS antenna

drive unit, high-powered radio

frequency units for the AWACS radar,

and other AWACS hardware. Boeing has

designed the LOX installation to

provide a supply of breathing oxygen

sufficient to allow operation of the

airplane in the unpressurized mode if

this becomes necessary. The FAA will

approve the performance of the oxygen

system during certification testing.

There are no specific regulations that

address the design and installation of

oxygen systems that utilize liquid

oxygen. Existing requirements, such as

§§ 25.1309, 25.1441 (b) & (c), 25.1451,

and 25.1453 in the Boeing Model 767–

27C original type certification basis,

applicable to this modification, provide

some design standards for crew and

medical oxygen system installations.

However, the FAA must specify

additional design standards for systems

utilizing liquid oxygen to ensure that an

acceptable level of safety is maintained.

Supplemental Type Certification Basis

Under the provisions of §§ 21.101 (a)

and (b), Boeing Commercial Airplane

Group must show that the modified

Model 767–27C continues to meet the

applicable provisions of the regulations

incorporated by reference in Type

Certificate (TC) No. A1NM, or the

applicable regulations in effect on the

date of application for the change. The

regulations incorporated by reference in

the type certificate are commonly

referred to as the ‘‘original type

certification basis.’’ The regulations

incorporated by reference in TC A1NM

are basically as follows: Part 25 of the

FAR, as amended by Amendments 25–

1 through 25–37, plus certain later

amended sections as specified in Type

Certificate Data Sheet A1NM. In

addition, the certification basis includes

certain special conditions, exemptions

and optional requirements that are not

relevant to these special conditions.

Also, the modified Model 767–27C must

continue to comply with the fuel

venting and exhaust emission

requirements of part 34 (previously

Special Federal Aviation Regulation 27),

and the noise certification requirements

of part 36 in effect on the date the STC

is issued.

If the Administrator finds that the

applicable airworthiness regulations

(i.e., part 25, as amended and

applicable) do not contain adequate or

appropriate safety standards for the

modified Model 767–27C 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 of the

FAR after public notice, as required by

§ 11.28 and § 11.29(b), and become part

of the type certification basis in

accordance with § 21.101(b)(2).

Special conditions are initially

applicable to the model for which they

are issued. Should the applicant apply

for a supplemental type certificate to

modify any other model included on the

same type certificate to incorporate the

same novel or unusual design feature,

the special conditions would apply to

the other model under the provisions of

§ 21.101(a)(1).

Discussion

There are no specific regulations that

address the design and installation of

oxygen systems that utilize liquid

oxygen for storage. Existing

requirements, such as §§ 25.1309,

25.1441 (b) and (c), 25.1451, and

25.1453 of the Boeing 767–200 series

certification basis applicable to this STC

project, provide some design standards

appropriate for oxygen system

installations. However, additional

design standards for oxygen systems

utilizing liquid oxygen are needed to

supplement the existing applicable

requirements. The quantity of liquid

oxygen involved in this installation and

the potential for unsafe conditions that

may result when the oxygen content of

an enclosed area becomes too high

because of system leaks, malfunction, or

damage from external sources, make it

necessary to assure adequate safety

standards are applied to the design and

installation of the system in Boeing

Model 767–27C airplanes.

To ensure that a level of safety is

achieved for modified Boeing Model

767–27C airplanes, utilizing liquid

oxygen as a storage medium for an

oxygen system, equivalent to that

intended by the regulations

incorporated by reference, special
53738 Federal Register / Vol. 62, No. 200 / Thursday, October 16, 1997 / Rules and Regulations

conditions are needed which require

those oxygen systems to be designed

and installed to preclude or minimize

the existence of unsafe conditions that

can result from system leaks,

malfunction, installation, or damage

from external sources.

Application by Boeing for approval of

oxygen systems utilizing liquid oxygen

as a storage medium installed in

transport airplanes, and the unsafe

conditions that can exist when the

oxygen content of an enclosed area

becomes too high because of system

leaks, malfunction, installation or

damage from external sources, make

development and application of

appropriate additional design and

installation standards necessary.

Discussion of Comments

On November 21, 1996, the FAA

published Notice of Proposed Special

Conditions No. SC–96–8–NM for the

Boeing Model 767–27C liquid oxygen

system installation in the Federal

Register (61 FR 59202). The Department

of the Air Force, commenting to the

docket by letter, recommended

additional requirements for design and

installation of the LOX system. Based on

some of those recommendations, the

FAA revised special conditions f. and

m. and republished the special

conditions as Supplemental Notice SC–

96–8A–NM on July 21, 1997 (62 FR

38945).

Boeing Commercial Airplane Group,

the applicant, provided the only

comments in response to Supplemental

Notice SC–96–8A.

Boeing suggests that paragraph ‘‘f’’ of

the special conditions be revised to

read:

‘‘The system shall include provisions

to ensure complete conversion of the

liquid oxygen to gaseous oxygen. The

resultant oxygen gas must be delivered

to the first oxygen outlet for breathing

such that the temperature is no more

than 35 °F less than the cabin ambient

temperature or 32 °F (whichever is

greater) under the conditions of the

maximum demand or flow of oxygen gas

for normal use of the oxygen

system. . . .’’

The commenter proposes this change

to address the case wherein the airplane

may be operated unpressurized, and

states that the purpose of the liquid

oxygen system being a part of the

AWACS modification is to provide a

supply of breathing oxygen sufficient to

allow operation of the airplane in the

unpressurized mode, if this becomes

necessary. The commenter’s suggested

revised wording would limit the lowest

temperature of oxygen provided to the

occupants to 32 °F during pressurized

and unpressurized operations.

The FAA concurs with the

commenter. In the original Notice SC–

96–8–NM for the Boeing Model 767–

27C liquid oxygen system, the FAA

proposed that the liquid oxygen system

should include provisions to ensure

complete conversion of the liquid

oxygen to gaseous oxygen. This

provision was included to address

possible hazards that would exist if

oxygen reaching the user was too cold.

The Department of the Air Force,

commenting in response to that notice,

suggested that the proposed special

condition be revised to further require

that oxygen gas delivered to the first

oxygen outlet for breathing have a

temperature that was not colder than 20

°F below the cabin ambient temperature

under the conditions of the maximum

demand or flow of oxygen gas for

normal use of the oxygen system. The

commenter did not provide a specific

reason to support this change. However,

the FAA determined that the proposal

was acceptable because it would ensure

that the oxygen is delivered to the user

at a temperature that is not harmful. The

FAA therefore revised paragraph ‘‘f’’ of

the proposed special condition

accordingly and issued Supplemental

Notice No. SC–96–8A–NM for comment.

The suggested temperature limits

proposed by Boeing in response to the

Supplemental Notice were reviewed by

the FAA, including specialists at the

FAA Civil Aeromedical Institute

(CAMI). From these reviews, the FAA

concluded that the suggested further

limiting of temperature limits to ‘‘no

more than 35 °F less than the cabin

ambient temperature or 32 °F

(whichever is greater)’’ is commensurate

with the basic intent of the proposed

special condition to ensure that the

oxygen is delivered at a safe

temperature to those breathing it. The

FAA considers that this change provides

an even higher level of safety than the

original proposal. As it affects only the

applicant who requested the change,

further noticing of the special

conditions is not considered necessary.

The remainder of the special

conditions for the 767–27C liquid

oxygen system installation are adopted

as proposed.

As discussed above, these special

conditions are applicable initially to the

Boeing Model 767–27C airplane. Should

Boeing Commercial Airplane Group

apply at a later date for a change to the

type certificate to include another

model incorporating the same novel or

unusual design feature, these 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

series of airplane. It is not a rule of

general applicability and affects only

the applicant who applied to the FAA

for approval of these features on the

airplane.

List of Subjects in 14 CFR Part 25

Aircraft, Aviation Safety, 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 Boeing Model

767–27C airplanes modified to an

AWACS configuration:

a. The liquid oxygen converter and

other oxygen equipment shall not be

installed where baggage, cargo, or loose

equipment are stored (unless items are

stored within an appropriate container

which is secured or restrained by

acceptable means).

b. The liquid oxygen converter shall

be located in the airplane so that there

is no risk of damage due to an

uncontained rotor or fan blade failure.

c. The liquid oxygen system and

associated gaseous oxygen distribution

lines should be designed and located to

minimize the hazard from uncontained

rotor debris.

d. The flight deck oxygen system shall

meet the supply requirements of Part

121 after the distribution line has been

severed by a rotor fragment.

e. The pressure relief valves on the

liquid oxygen converters shall be vented

overboard through a drain in the bottom

of the airplane. Means must be provided

to prevent hydrocarbon fluid migration

from impinging upon the vent outlet of

the liquid oxygen system.

f. The system shall include provisions

to ensure complete conversion of the

liquid oxygen to gaseous oxygen. The

resultant oxygen gas must be delivered

to the first oxygen outlet for breathing

such that the temperature is no more

than 35 °F less than the cabin ambient

temperature or 32 °F (whichever is

greater), under the conditions of the

maximum demand or flow of oxygen gas

for normal use of the oxygen system. A

LOX shutoff valve shall be installed on

the main oxygen distribution line prior

to any secondary lines. The shutoff
Federal Register / Vol. 62, No. 200 / Thursday, October 16, 1997 / Rules and Regulations 53739

valve must be compatible with LOX

temperatures and be readily accessible

(either directly if manual, or by remote

activation if automatic).

g. If multiple converters are used and

manifolded together, check valves shall

be installed so that a leak in one

converter will not allow leakage of

oxygen from any other converter.

h. Flexible hoses shall be used for the

airplane systems connections to shockmounted converters, where movement

relative to the airplane may occur.

i. Condensation from system

components or lines shall be collected

by drip pans, shields, or other suitable

collection means and drained overboard

through a drain fitting separate from the

liquid oxygen vent fitting, as specified

in Special Condition e. above.

j. Oxygen system components shall be

burst pressure tested to 3.0 times, and

proof pressure tested to 1.5 times, the

maximum normal operating pressure.

Compliance with the requirement for

burst testing may be shown by analysis,

or a combination of analysis and test.

k. Oxygen system components shall

be electrically bonded to the airplane

structure.

l. All gaseous or liquid oxygen

connections located in close proximity

to an ignition source shall be shrouded

and vented overboard using the system

specified in Special Condition e. above.

m. A means will be provided to

indicate the quantity of oxygen in the

converter and oxygen availability to the

flightcrew. A low LOX level amber

caution annunciation will be furnished

to the flightcrew prior to the LOX

converter oxygen level reaching the

quantity required to provide sufficient

oxygen for emergency descent

requirements.

Issued in Renton, Washington, on October

1, 1997.

Darrell M. Pederson,

Acting Manager, Transport Airplane

Directorate, Aircraft Certification Service,

ANM–100.

[FR Doc. 97–27503 Filed 10–15–97; 8:45 am]

BILLING CODE 4910–13–P

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 71

[Airspace Docket No. 97–AAL–9]

Revocation of Class D Airspace;

Anchorage, Bryant AHP, AK, and Adak,

AK; Revision of Class E Airspace;

Adak, AK

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This action revokes the Class

D airspace at Bryant Army Heliport

(AHP), Anchorage, AK, and at Adak

Naval Air Station (NAS), AK. The

Department of the Army closed the

Bryant AHP tower on September 27,

1995, and transferred operational

control of Bryant AHP to the Alaska

National Guard. The Department of the

Navy closed the Adak tower on March

31, 1997, following the approval of the

1995 Base Realignment and Closure

Commission’s recommendation to close

Adak NAS, AK, by the Congress of the

United States. Additionally, the Class E

airspace description at Adak, AK, will

be revised to reflect part-time (less than

24-hours a day) operations. The

intended effect of this action is to revise

the effective times for the Class E

airspace at Adak, AK, and also to revoke

the Class D airspace at Bryant AHP, and

at Adak NAS, AK, since the purpose

and requirements for these surface areas

no longer exist.

EFFECTIVE DATE: 0901 Coordinated

Universal Time (UTC), November 17,

1997.

FOR FURTHER INFORMATION CONTACT:

Robert van Haastert, Operations Branch,

AAL–538, Federal Aviation

Administration, 222 West 7th Avenue,

Box 14, Anchorage, AK 99513–7587;

telephone number (907) 271–5863;

email; Robert.van.Haastert@faa.dot.gov;

Internet: http://www.alaska.faa.gov/at or

at http://162.58.28.41/at.

SUPPLEMENTARY INFORMATION:

Background

The Department of the Army closed

the Bryant AHP tower on September 27,

1995, and transferred operational

control of Bryant AHP to the Alaska

National Guard. The Department of the

Navy closed the Adak NAS tower on

March 31, 1997, following the approval

of the 1995 Base Realignment and

Closure Commission’s recommendation

to close Adak NAS, AK, by the Congress

of the United States. The purpose and

requirements for these Class D surface

areas no longer exist. The Class E

effective times at Adak, AK, currently

reflect continuous, 24-hour a day

operations. This situation no longer

exists and the effective times will be

changed to indicate a part-time

operation.

The coordinates for this airspace

docket are based on North American

Datum 83. The Class D airspace areas

designated as surface areas are

published in paragraph 5000 of FAA

Order 7400.9E, Airspace Designations

and Reporting Points, dated September

10, 1997, and effective September 16,

1997, which is incorporated by

reference in 14 CFR 71.1(62 FR 52491;

October 8, 1997). FAA Order 7400.9E,

paragraph 6004, lists the Class E

airspace areas designated as an

extension to a Class D or Class E surface

area. The Class D airspace descriptions

listed in this document will be removed

from the Order. The Class E airspace

revision listed in this document will be

published subsequently in the Order.

The Rule

The FAA is amending part 71 of the

Federal Aviation Regulations (14 CFR

part 71) to revoke the Class D airspace

at Bryant Army Heliport (AHP),

Anchorage, AK and at Adak NAS, AK.

Additionally, the Class E effective times

at Adak NAS, AK, will change from

continuous to part time. The Class D

airspace designation listed in this

document will be revoked and the Class

E airspace revision listed in this

document will be published with two

additional sentences to reflect the parttime effective times.

Accordingly, since the purpose and

requirements for the Class D surface

areas at Bryant AHP and Adak NAS no

longer exist, notice and public

procedure under 5 U.S.C. 553(b) for

revoking this airspace are unnecessary.

Since the closure of the tower is merely

causing a reduction of the effective

hours of the Class E airspace at Adak

NAS, notice and public procedure

under 5 U.S.C. 553(b) is unnecessary.

The FAA has determined that these

regulations only involve an established

body of technical regulations for which

frequent and routine amendments are

necessary to keep them operationally

current. It, therefore—(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)

does not warrant preparation of a

regulatory evaluation as the anticipated

impact is so minimal. Since this is a

routine matter that will only affect air

traffic procedures and air navigation, it

is certified that this rule, when

promulgated, will not have a significant

economic impact on a substantial

number of small entities under the

criteria of the Regulatory Flexibility Act.

List of Subjects in 14 CFR Part 71

Airspace, incorporation by reference,

Navigation (air).

Adoption of the Amendment

In consideration of the foregoing, the

Federal Aviation Administration

amends 14 CFR part 71 as follows: