Federal Register / Vol. 62, No. 248 / Monday, December 29, 1997 / Rules and Regulations 67555

Issued in Washington, DC, on December

17, 1997.

Nancy B. Kalinowski,

Acting Program Director for Air Traffic

Airspace Management.

[FR Doc. 97–33760 Filed 12–24–97; 8:45 am]

BILLING CODE 4910–13–U

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 91

[Docket No. 28870; Amendment No. 91–254]

RIN 2120–AE51

Reduced Vertical Separation

Operations

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Disposition of comments on

final rule.

SUMMARY: On March 27, 1997, the FAA

adopted requirements for Reduced

Vertical Separation Minimum (RVSM)

airspace. The rule provided

requirements for operating in airspace

between flight level (FL) 290 and FL

410, with assigned altitudes separated

by a minimum of 1,000 feet, rather than

the 2,000 foot minimum separation

previously required above FL 290. The

amendment made more tracks and

altitudes available for air traffic control

to assign to operators, thus increasing

efficiency of operations and air traffic

capacity. The action maintained a level

of safety equal to or greater than that

provided by the previous regulations by

requiring improved altitude-keeping

performance to participate in RVSM.

This action is a summary and

disposition of comments received on the

final rule.

ADDRESSES: The complete docket for the

final rule on RVSM may be examined at

the Federal Aviation Administration,

Office of the Chief Counsel, Attn: Rules

Docket (AGC–200), Room 915–G, Docket

No. 28870, 800 Independence Ave., SW,

Washington, DC 20591, weekdays

(except federal holidays) between 9:00

a.m. and 5:00 p.m.

FOR FURTHER INFORMATION CONTACT:

Roy Grimes, AFS–400 Technical

Programs, Division, Flight Standards

Service, Federal Aviation

Administration, 800 Independence

Avenue SW., Washington, DC 20591,

telephone (202) 267–3734.

SUPPLEMENTARY INFORMATION:

Background

With air traffic increasing annually

worldwide, FAA airspace planners and

their international counterparts

continually study methods of enhancing

the air traffic control (ATC) system’s

ability to accommodate this traffic in a

safe and efficient manner. The traffic

problem has become particularly acute

in the North Atlantic (NAT) airspace,

where the number of flight operations

increased 30 percent from 1988 through

1992, according to the NAT Traffic

Forecasting Group. The forecast

indicated that traffic will rise 60 percent

over the 1992 level of 228,200

operations by 2005. Currently, 27

percent of operations in the NAT

airspace receive clearances on tracks

and to altitudes other than those

requested by the operators in their filed

flight plans because of airspace

limitations. These flights are conducted

at less than optimum tracks and

altitudes for the aircraft, resulting in

time and fuel inefficiencies.

One limitation on air traffic

management at high altitudes is the

required vertical separation. At altitudes

lower than FL 290, air traffic controllers

can assign aircraft operating under

Instrument Flight Rules (IFR) altitudes a

minimum of 1,000 feet apart, however,

above FL 290, the required vertical

separation was a minimum of 2,000 feet

prior to this final rule. (Note: Flight

levels are stated in digits that represent

hundreds of feet. The term flight level

is used to describe a surface of constant

atmospheric pressure related to a

reference datum of 29.92 inches of

mercury. Rather than adjusting

altimeters for changes in atmospheric

pressure, pilots base altitude readings

above the transition altitude (in the

United States, 18,000 feet) on this

standard reference. FL 290 represents

29,000 feet; FL 310 represents 31,000

feet, and so on.)

The 2,000 ft minimum vertical

separation above FL 290 previously

restricted the number of flight levels

available, even though many more air

carrier and general aviation aircraft are

capable of high altitude operations now

than when the 2000-foot separation

standard was established. Flight levels

310, 330, 350, 370, and 390 are flight

levels at which aircraft crossing between

North America and Europe operate most

economically, thus causing congestion

at peak hours. Now, with the issuance

of the RVSM final rule, air traffic can

make available other flight levels, such

as 320, 340, 360, and 380. Exhaustive

technical studies showed that a 1,000 ft

minimum vertical separation was both

feasible and safe. The solution was

based on marked improvement in

altitude-keeping technology and

provided relief from the fuel and time

inefficiencies seen in the North Atlantic

Minimum Navigation Performance

Specifications (NAT MNPS) airspace

prior to the issuance of the RVSM final

rule.

Discussion of Comments

The FAA received three comments on

the RVSM final rule.

The first commenter, the Air Line

Pilots’ Association (ALPA), states that

some pilots have been receiving traffic

advisories (TA’s) from their Traffic Alert

and Collision Avoidance Systems

(TCAS). The TA’s have been

encountered between same direction

aircraft separated by 1000 feet, that are

in close longitudinal proximity to each

other with similar cruising speeds.

ALPA writes that pilots have reported

TA’s lasting as long as twenty minutes,

requiring innovative actions to

eliminate them. They point out a lack of

defined procedures for handling

annoying TA’s. Although ALPA is not

aware of an occurrence, they believe the

current TCAS logic leaves open the

possibility of a disruptive long duration

resolution advisory (RA) in the RVSM

environment. Their concern is the

possibility that this type of event could

cause a serious problem in RVSM

airspace from the close proximity of

traffic and pilot training that requires

compliance with RA commands.

ALPA’s second area of concern is

wake vortex encounters. Pilots have

reported numerous encounters with

turbulence produced by B–747 and B–

777 aircraft using RVSM separation.

Although ALPA is not aware of any

serious cases reported, these operational

characteristics did not exist when the

2000 foot standard was in use. ALPA

points out the absense of procedures to

help pilots avoid or exit areas of

descending vortex.

ALPA recommends the development

of an operations plan by the North

Atlantic Systems Planning Group

(NATSPG) which would provide

procedures that could resolve both the

TCAS and wake vortex problems. Some

suggestions included lateral offset,

Mach number change so as to change

longitudinal geometries, and planned

offset of each odd or even flight level.

ALPA also suggests a centralized data

collecting effort that ensures the

reporting of TCAS and wake vortex

events. They believe the two problems

could best be evaluated through the

collection of data for analysis and

processing.

The FAA appreciates ALPA’s

comments regarding the effect of RVSM

on TCAS operations. The FAA, in

conjunction with the other North

Atlantic air traffic service (ATS)

providers has requested that the ARINC
67556 Federal Register / Vol. 62, No. 248 / Monday, December 29, 1997 / Rules and Regulations

Corporation conduct a study of TCAS in

NAT RVSM airspace. (ARINC already

provides contract support to the FAA

TCAS Program Office as well as the

NATSPG). The purpose of this study is

to better understand the parameters that

can lead to multiple traffic alerts and

also to understand better the

performance of TCAS change 7 in the

RVSM environment. This study began

in September 1997.

In regards to wake turbulence

encounters, the FAA, in coordination

with the NAT ATS providers, has

published a contingency procedure that

gives a pilot encountering wake

turbulence the option of offsetting from

the track to avoid the turbulence. This

procedure has been coordinated with

the International Federation of Air Line

Pilots’ Association (IFALPA) and was

published by the NAT ATS providers in

September, 1997.

The second commenter, National Air

Transportation Association (NATA),

states concern that future expansion of

the RVSM operational altitudes would

not address the hundreds of business

aircraft currently operating over the

North Atlantic. NATA’s concern comes

from the apparent lack of concern from

‘‘aircraft manufacturers to provide

support for upgrading a previously

manufactured aircraft’s systems to meet

RVSM specifications.’’ NATA also

believes that a substantial financial

investment is required to meet RVSM

specifications, and that expenditure is

beyond the ability of many aircraft

operators.

The FAA will be working with the

user community to develop a position

on the expansion of RVSM flight levels

in the NAT. A U.S. position on this

issue will be needed for the December

1997 meeting of the NAT

Implementation Managers’ Group. To

accomplish this, the FAA held a

meeting of the RVSM Steering Group in

September 1997. At this meeting, the

user community, including NATA, was

given the opportunity to express their

views on RVSM expansion. There will

also be a follow-up meeting in

December, 1997. Also, the International

Business Aviation Council has been

given the opportunity to provide a

representative to the December meeting.

A major issue to be addressed is the

readiness of the business aircraft fleet to

operate within RVSM.

The third commenter, an individual

pilot, believes the implementation of

RVSM is too broad. The commenter

asked why the program was not

implemented in ‘The Tracks’ first. Then

asked, why is there an absence of a ‘Non

RVSM’ corridor similar to the VFR

corridor in Los Angeles.

In response, the final rule provided

for the phased implementation of RVSM

over the North Atlantic between FL 330

and FL 370 initially. Other non-RVSM

equipped aircraft are free to operate

above or below the RVSM altitudes. The

FAA has determined that the benefits of

the increased efficiency within the

RVSM airspace far outweigh the

inconvenience this rule may impose on

a small percentage of aircraft without

the needed equipment.

Conclusion

After consideration of the comments

submitted in response to the final rule,

the FAA has determined that no further

rulemaking action is necessary.

Amendment 91–254 remains in effect as

adopted.

Issued in Washington, DC on December 19,

1997.

Jane F. Garvey,

Administrator.

[FR Doc. 97–33753 Filed 12–24–97; 8:45 am]

BILLING CODE 4910–13–M

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 97

[Docket No. 29074; Amdt. No. 1840]

RIN 2120–AA65

Standard Instrument Approach

Procedures; Miscellaneous

Amendments

AGENCY: Federal Aviation

Administration (FAA), DOT.

ACTION: Final rule.

SUMMARY: This amendment establishes,

amends, suspends, or revokes Standard

Instrument Approach Procedures

(SIAP’s) for operations at certain

airports. These regulatory actions are

needed because of the adoption of new

or revised criteria, or because of changes

occurring in the National Airspace

System, such as the commissioning of

new navigational facilities, addition of

new obstacles, or changes in air traffic

requirements. These changes are

designed to provide safe and efficient

use of the navigable airspace and to

promote safe flight operations under

instrument flight rules at the affected

airports.

DATES: An effective date for such SIAP

is specified in the amendatory

provisions.

Incorporation by reference-approved

by the Director of the Federal Register

on December 31, 1980, and reapproved

as of January 1, 1982.

ADDRESSES: Availability of matters

incorporated by reference in the

amendment is as follows:

For Examination

1. FAA Rules Docket, FAA

Headquarters Building, 800

Independence Avenue, SW.,

Washington, DC 20591;

2. The FAA Regional Office of the

region in which the affected airport is

located; or

3. The Flight Inspection Area Office

which originated the SIAP.

For Purchase

Individual SIAP copies may be

obtained from:

1. FAA Public Inquiry Center (APA–

200), FAA Headquarters Building, 800

Independence Avenue, SW.,

Washington, DC 20591; or

2. The FAA Regional Office of the

region in which the affected airport is

located.

By Subscription

Copies of all SIAP’s, mailed once

every 2 weeks, are for sale by the

Superintendent of Documents, U.S.

Government Printing Office,

Washington, DC 20402.

FOR FURTHER INFORMATION CONTACT: Paul

J. Best, Flight Procedures Standards

Branch (AFS–420), Technical Programs

Division, Flight Standards Service,

Federal Aviation Administration, 800

Independence Avenue, SW.,

Washington, DC 20591; Telephone (202)

267–8277.

SUPPLEMENTARY INFORMATION: This

amendment to part 97 of the Federal

Aviation Regulations (14 CFR part 97)

establishes, amends, suspends, or

revokes SIAP’s. The complete regulatory

description of each SIAP is contained in

official FAA form documents which are

incorporated by reference in this

amendment under 5 U.S.C. 552(a), 1

CFR part 51, and § 14 CFR 97.20 of the

Federal Aviation Regulations (FAR).

The applicable FAA Forms are

identified as FAA Form 8260–5.

Materials incorporated by reference are

available for examination or purchase as

stated above.

The large number of SIAP’s, their

complex nature, and the need for a

special format make their verbatim

publication in the Federal Register

expensive and impractical. Further,

airmen do not use the regulatory text of

the SIAP’s, but refer to their graphic

depiction on charts printed by

publishers of aeronautical materials.

Thus, the advantages of incorporation

by reference are realized and

publication of the complete description

of each SIAP contained in FAA form