[Federal Register Volume 62, Number 68 (Wednesday, April 9, 1997)]
[Rules and Regulations]
[Pages 17480-17489]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-8367]
[[Page 17479]]
_______________________________________________________________________
Part III
Department of Transportation
_______________________________________________________________________
Federal Aviation Administration
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14 CFR Part 91
Reduced Vertical Separation Minimum Operations; Final Rule
Federal Register / Vol. 62, No. 68 / Wednesday, April 9, 1997 / Rules
and Regulations
[[Page 17480]]
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DEPARTMENT OF TRANSPORTATION
Federal Aviation Administration
14 CFR Part 91
[Docket No. 28870; Amdt No. 91-254]
RIN 2120-AE51
Reduced Vertical Separation Minimum Operations
AGENCY: Federal Aviation Administration, DOT.
ACTION: Final rule; request for comments.
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SUMMARY: The Federal Aviation Administration (FAA) is establishing
requirements for operations of U.S.-registered aircraft in airspace
designated as Reduced Vertical Separation Minimum (RVSM) airspace. RVSM
refers to 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 currently required above FL 290. The
current requirement is based on navigation equipment with a level of
accuracy that necessitated a 2,000 foot buffer. Modern navigation
equipment permits more precise navigation, including altitude control.
These regulations require operators and their aircraft to be approved
in accordance with new requirements, in order to operate in RVSM
specified airspace. The regulations ensure that operators and their
aircraft are properly qualified and equipped to conduct flight
operations while separated by 1,000 feet, and ensure that compliance
with the RVSM requirements is maintained. This amendment makes more
tracks and altitudes available for air traffic control to assign to
operators, thus increasing efficiency of operations and air traffic
capacity. This action maintains a level of safety equal to or greater
than that provided by the current regulations. RVSM will be applied in
designated areas, with the first area being certain flight levels in
the North Atlantic (NAT) Minimum Navigation Performance Specifications
(MNPS) airspace.
DATES: This final rules is effective April 9, 1997. Comments must be
submitted on or before June 9, 1997.
ADDRESSES: Substantive comments on this action should be delivered or
mailed, in triplicate, to: Federal Aviation Administration, Office of
the Chief Counsel, Attention: Rules Docket (AGC-200), Room 915-G,
Docket No. 28870, 800 Independence Avenue, SW., Washington, DC 20591.
Comments delivered must be marked Docket No. 28870. Substantive
comments also may be submitted electronically to the following Internet
address: [email protected]. Comments may be examined in Room 915G
weekdays between 8:30 a.m. and 5:00 p.m., except on Federal holidays.
FOR FURTHER INFORMATION CONTACT:
Mr. 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:
Substantive Comments Invited
This action is a product of international agreements under which
the international aviation community, including the United States, is
prepared to and plans to begin operational testing of the RVSM
procedures in certain altitudes on March 27, 1997. Arriving air
traffic, having departed Europe and separated at RVSM altitudes, cannot
as a practical matter arrive in oceanic airspace controlled by the
United States, all needing to be reassigned to a pre-RVSM separation
altitude. Unless this rule is implemented by March 27, 1997, there
would have to be major delays for westbound NAT traffic in airspace
that the FAA does not control, to avoid a significant safety problem.
Because the United States international commitments in this matter
cannot otherwise reasonably be met and because of the potential safety
problem for aircraft entering U.S.-controlled oceanic airspace without
the benefit of this rule, the FAA is publishing this action as a final
rule without an opportunity for public comment. It should be noted,
however, that this action has been developed through the international
committee process, a variety of related program meetings, and a formal
public meeting in 1993. No significant adverse comment was received.
If an individual believes that a significant salient issue has been
overlooked, that person is invited to comment by submitting such
written data, views, or arguments as they may desire. Comments should
identify the regulatory docket number and should be submitted in
triplicate to the Rules Docket address specified above. Because this
rule was developed as a result of an international agreement, comments
deemed substantive will be presented for consideration and reviewed by
the international community under the auspices of ICAO. If considered
salient, the comment will be included for use by all participating
member States.
All comments received will be available, both before and after the
closing date for comments, in the Rules Docket for examination by
interested persons. Commenters wishing the FAA to acknowledge receipt
of their comments must include a preaddressed, stamped postcard on
which the following statement is made: ``Comments to Docket No.
28870.'' The postcard will be date stamped and returned to the
commenter.
Availability of This Document
An electronic copy of this document may be downloaded using a modem
and suitable communications software from the FAA regulations section
of the Fedworld electronic bulletin board service (telephone 703-321-
3339), the Federal Register's electronic bulletin board service
(telephone: 202-512-1661), or the FAA's Aviation Rulemaking Advisory
Committee Bulletin Board Service (telephone: 202-267-5948).
Internet users may reach the FAA's web page at http://www.faa.gov
or the Federal Register's webpage at http://www.access.gpo/su__docs for
access to recently published rulemaking documents.
Any person may obtain a copy of this document by submitting a
request to the Federal Aviation Administration, Office of Rulemaking,
ARM-1, 800 Independence Avenue, SW., Washington, DC 20591, or by
calling (202) 267-9677. Communications must identify the docket number
of this rule.
Persons interested in being placed on the mailing list for future
rulemaking actions should request from the above office a copy of
Advisory Circular No. 11-2A, Notice of Proposed Rulemaking Distribution
System, that describes the application procedure.
Background
Statement of the Problem
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 NAT airspace, where the
number of flight operations increased 30 percent from 1988 through
1992, according to the NAT Traffic Forecasting Group. The forecast
indicates 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
[[Page 17481]]
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. Whereas at lower altitudes air traffic
controllers can assign aircraft operating under Instrument Flight Rules
(IFR) altitudes a minimum of 1,000 feet apart, above FL 290, required
vertical separation is a minimum of 2,000 feet.
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 foot vertical separation minimum applied above FL 290 in
U.S. and international airspace dates to the 1950's. At that time,
high-altitude flight was possible for only a limited number of military
aircraft, and inaccuracies in altitude-keeping systems were evident
above FL 290. (``Altitude-keeping'' means the accuracy in the vertical
plane with which an aircraft adheres to its assigned pressure altitude
using the aircraft altitude-keeping and barometric altimeter systems.)
However, advances in technology eventually gave transport and general
aviation aircraft the ability to operate at higher altitudes, resulting
in increased traffic along high-altitude routes.
The 2,000 ft minimum vertical separation restricts 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 standard was established. Flight levels 310, 330, 350, 370, and 390
are the flight levels at which aircraft crossing between North America
and Europe operate most economically, thus causing congestion at peak
hours. One solution to air traffic management limitations would be to
make available other flight levels, such as 320, 340, 360, and 380.
Exhaustive technical studies show that a 1,000 ft minimum vertical
separation is feasible and safe. The solution is based on marked
improvement in altitude-keeping technology and provides relief from the
fuel and time inefficiencies being seen in the NAT MNPS airspace.
History
Rising traffic volume and fuel costs, which made flight at fuel
efficient altitudes a priority for operators, sparked an interest in
the early 1970's in implementing RVSM above FL 290. In April 1973, the
Air Transport Association of America (ATA) petitioned the FAA for a
rule change to reduce the vertical separation minimum to 1,000 feet for
aircraft operating above FL 290. The petition was denied in 1977 in
part because (1) aircraft altimeters had not been improved
sufficiently, (2) improved maintenance and operational standards had
not been developed, and (3) altitude correction was not available in
all aircraft. In addition, the cost of modifying nonconforming aircraft
was prohibitive. The FAA concluded that granting the ATA petition at
that time would have adversely affected safety.
Nevertheless, the FAA recognized the potential benefits of RVSM
under certain circumstances and continued to review technological
developments, committing extensive resources to studying aircraft
altitude-keeping performance and necessary criteria for safely reducing
vertical separation above FL 290. These benefits and data showing that
implementing RVSM is technically feasible have been demonstrated in
studies conducted cooperatively in international forums, as well as
separately by the FAA.
Because of the high standard of performance and equipment required
for RVSM, the FAA foresees initial introduction of RVSM in oceanic
airspace where special navigation performance standards already exist.
(Special navigation areas require high levels of long-range navigation
precision due to the separation standard applied). RVSM implementation
in such airspace requires an increased level of precision demanded of
operators, aircraft, and vertical navigation systems.
In 1997, RVSM is planned only for one such special navigation area
of operation, the NAT MNPS, established in the International Civil
Aviation Organization (ICAO) NAT Region. In designated NAT MNPS
airspace, tracks are spaced 60 nautical miles (nm) apart. On these
tracks, aircraft are separated vertically by 2000 feet. All aircraft
operating in this airspace must be appropriately equipped and capable
of meeting the MNPS standards. Operators must follow procedures that
ensure the standards are met, and flightcrews must be trained and
qualified to meet the MNPS standards. Each operator, aircraft, and
navigation system combination must receive and maintain authorization
to operate in the NAT MNPS. The NATSPG Central Monitoring Agency for
the NAT Systems Planning Group monitors NAT aircraft fleet performance
to ensure that a safe operating environment is maintained.
FAA data indicate that the altitude-keeping performance of most
aircraft flying in the NAT could meet the standards for RVSM
operations. The FAA and ICAO research to determine the feasibility of
implementing RVSM in the NAT MNPS included the following four efforts:
1. FAA Vertical Studies Program. This program began in mid-1981,
with the objectives of collecting and analyzing data on aircraft
performance in maintaining assigned altitude, developing program
requirements to reduce vertical separation, and providing technical and
operational representation on the various working groups studying the
issue outside the FAA.
2. RTCA Special Committee (SC)-150. RTCA, Inc., (formerly Radio
Technical Commission for Aeronautics) is an industry organization in
Washington, DC, that addresses aviation technical requirements and
concepts and produces recommended standards. When the FAA hosted a
public meeting in early 1982 on vertical separation, it was recommended
that RTCA be the forum for development of minimum system performance
standards for RVSM. RTCA SC-150 was formed in March 1982 to develop
minimum system performance requirements, identify required improvements
to aircraft equipment and changes to operational procedures, and assess
the impact of the requirements on the aviation community. SC-150 served
as the focal point for the study and development of RVSM criteria and
programs in the United States from 1982 to 1987, including analysis of
the results of the FAA Vertical Studies Program.
3. ICAO Review of the General Concept of Separation Panel (RGCSP).
In 1987, the FAA concentrated its resources for the development of RVSM
programs in the ICAO RGCSP. The U.S. delegation to the ICAO RGCSP used
the material developed by SC-150 as the foundation for U.S. positions
and plans on RVSM criteria and programs. The panel's major conclusions
were:
RVSM is ``technically feasible without imposing
unreasonably demanding technical requirements on the equipment.''
RVSM provides ``significant benefits in terms of economy
and en route airspace capacity.''
Implementation of RVSM on either a regional or global
basis requires ``sound operational judgment supported
[[Page 17482]]
by an assessment of system performance based on: Aircraft altitude-
keeping capability, operational considerations, system performance
monitoring, and risk assessment.''
4. NATSPG and the NATSPG Vertical Separation Implementation Group
(VSIG).
The NATSPG Task Force was established in 1988 to identify the
requirements to be met by the future NAT Region air traffic services
system; to design the framework for the NAT airspace system concept;
and to prepare a general plan for the phased introduction of the
elements of the concept. The objective of this effort was to permit
``significant increases in airspace capacity and improvements in flight
economy.'' At the meeting of the NATSPG in June 1991, all of the NAT
air traffic service provider States, as well as the International Air
Transport Association (IATA) and International Federation of Airline
Pilots Association (IFALPA), endorsed the Future NAT Air Traffic
Services System Concept Description developed by the NATSPG Task Force.
With regard to the implementation of RVSM, the Concept Description
concludes that ``priority must be given to implementation of this
measure as it is believed to be achievable within the early part of the
concept timeframe.'' NATSPG's initial goal was to implement RVSM
between 1996 and 1997. To meet this goal, the NATSPG established the
VSIG in June 1991 to take the necessary actions to implement RVSM in
the NAT. These actions included:
Programs and documents to approve aircraft and operators
to conduct flight in the RVSM environment and to address all issues
related to aircraft airworthiness, maintenance, and operations. The
group has produced guidance material for aircraft and operator
approval, which ICAO has distributed to civil aviation authorities and
NAT users. ICAO has planned that the guidance material be incorporated
in the approval process established by the States.
Developing the system for monitoring aircraft altitude-
keeping performance. This system is used to observe aircraft
performance in the vertical plane to determine that the approval
process is uniformly effective and that the RVSM airspace system is
safe.
Evaluating and developing ATC procedures for RVSM,
conducting simulation studies to assess the effect of RVSM on ATC, and
developing documents to address ATC issues.
The NATSPG RVSM implementation program was endorsed by the ICAO
Limited NAT Regional Air Navigation Meeting held in Portugal in
November 1992. At that meeting, it was concluded that RVSM
implementation should be pursued. The FAA concurred with the
conclusions of the NATSPG on RVSM implementation.
On August 17, 1993, the FAA held a public meeting to obtain input
and data that would be considered by the FAA in determining if and how
to implement reduced vertical separation in appropriate airspace. The
32 meeting participants included representatives of the aviation
industry, including manufacturers and air carriers, and unions, as well
as pilots and government officials. Five members of the public made
formal statements.
The ATA supported RVSM, indicating that the FAA should proceed as
quickly as possible with implementation because of direct economic
benefit for airlines. A member of the ATA supported the concept and
indicated that Traffic Alert and Collision Avoidance Systems (TCAS)
should be included in the system specifications. The speaker indicated
that, in his analysis, no changes to the TCAS system would be needed to
implement the reduced vertical separation.
The Airline Pilots Association (ALPA) supported RVSM, but expressed
concern that the engineering requirements were so complex that
continuing compliance could be difficult. Therefore, ALPA emphasized
that there must be an ongoing effort to collect data on altitude
keeping performance through monitoring to prevent those not meeting the
requirements from entering or using RVSM airspace.
The National Air-Traffic Controllers' Association (NATCA) opposed
RVSM at that time because of the potential increase in traffic volume
in RVSM airspace without a corresponding increase in the number of
controllers. However, the NATCA speaker said the increase in oceanic
capacity through RVSM implementation should be pursued when the FAA
fully staffs the air traffic control system and provides adequate
automation to aid the controllers.
(In the interim since the August, 1993 public meeting, the FAA
conducted a series of real time simulations at the FAA Technical
Center's National Simulation Capability (NSC). Simulations where
conducted to assist the FAA's Air Traffic organizations in defining
geographical areas for RVSM transitioning and establishing procedures
to effect that transition. Controllers, and controllers representing
NATCA, from New York, Boston and Miami Air Route Traffic Control
Centers, participated in the simulations. As indicated in the National
Simulation Capability RVSM Phase I Result Report, August 1995, the
simulation results indicated that, while interval increases in
controller workload occurred under RVSM traffic conditions when
compared with conventional vertical separation minima (2000 feet)
conditions, the overall controller workload did not increase. High
interval workload did not interfere with a controller's ability to
provide service to the aircraft. Based upon the Phase I RVSM simulation
results, the introduction of RVSM in the New York Oceanic Airspace is
feasible provided that certain procedures are well defined and agreed
upon prior to implemention.)
The National Business Aircraft Association (NBAA) supported the
reduced vertical separation concept. However, NBAA expressed concern
over the cost of equipping aircraft to enter RVSM airspace. Also, NBAA
was concerned that if the RVSM concept was to be considered for the
Pacific area and domestic airspace, significant expense to operators
could result from the requirement for all airplanes to be equipped,
validated, and maintained to RVSM standards. NBAA viewed this as a
significant long-range cost impact.
Reference Material
The FAA and other entities studying the issue of RVSM requirements
have produced a number of studies and reports. The FAA used the
following documents in the development of this amendment.
Summary Report of United States Studies on 1,000-Foot
Vertical Separation Above Flight Level 290 (FAA, July 1988).
Initial Report on Minimum System Performance Standards
for 1,000-Foot Vertical Separation Above Flight Level 290 (RTCA SC-
150, November 1984); the report provides information on the
methodology for evaluating safety, factors influencing vertical
separation, and strawman system performance standards.
Minimum System Performance Standards for 1,000-Foot
Vertical Separation Above Flight Level 290 (Draft 7, RTCA, August
1990); the FAA concurred with the material developed by RTCA SC-150.
The Report of RGCSP/6 (ICAO, Montreal, 28 November-15
December 1988) published in two volumes. Volume 1 summarizes the
major conclusions reached by the panel and the individual States.
Volume 2 presents the complete RVSM study reports of the individual
States:
European Studies of Vertical Separation Above FL 290--
Summary Report (prepared by the Eurocontrol Vertical Studies
Subgroup).
[[Page 17483]]
Summary Report of United States Studies on 1,000-Foot
Vertical Separation Above Flight Level 290 (prepared by the FAA
Technical Center and ARINC Research Corporation).
The Japanese Study on Vertical Separation.
The Report of the Canadian Mode C Data Collection.
The Results of Studies on the Reduction of Vertical
Separation Intervals for USSR Aircraft at Altitudes Above 8,100 m
(prepared by the USSR).
Report of RGCSP/7 (Montreal, 30 October-20 November
1990) containing a draft Manual on Implementation of a 300 M (1,000
Ft) Vertical Separation Minimum (VSM) Between FL 290 and 410
Inclusive, approved by the ICAO Air Navigation Commission in
February 1991 and published as ICAO Document 9574.
Interim Guidance Material 91-RVSM, ``Approval of
Aircraft and Operators for Flight in Airspace Above FL 290 Where a
1,000 Foot Vertical Separation is Applied'' (March 14, 1994). (The
interim guidance continues to provide recommended procedural steps
for obtaining FAA approval.)
AC No. 91-70, ``Oceanic Operations'' (September 6,
1994).
Flight Standards Handbook Bulletin for Air
Transportation (HBAT) ``Approval of Aircraft and Operators for
Flight in Airspace Above Flight Level 290 Where a 1,000 Foot
Vertical Separation Minimum is Applied'' (HBAT 97-02).
Related Activity
The FAA plans to implement RVSM starting in the NAT MNPS airspace
because of the data and operational controls available for this
airspace, and because of the operational efficiency problems in that
airspace. The FAA's groundwork for determining the feasibility of RVSM
and developing this rule has been carried out in conjunction with the
NATSPG's plans to implement RVSM in the NAT MNPS Airspace.
Implementation is occurring in two phases:
1. Verification Phase
During the verification phase, aircraft have continued to be
vertically separated by 2,000 feet, and operators and aircraft have
begun to receive RVSM approval in accordance with the FAA's ``Interim
Guidance Material'' (91-RVSM).
The overall objectives of the verification phase are to:
1. Confirm that the NAT target level of safety (TLS) will continue
to be met.
2. Confirm that aircraft approved for RVSM operation demonstrate
altitude-keeping performance that meets RVSM standards. This will be
achieved by:
Identifying and eliminating any causes of out-of-tolerance
altitude-keeping performance, in general or for specific aircraft
groups; and
Monitoring a sample of RVSM-approved aircraft and
operators that is representative of the total NAT MNPS population.
3. Verify that operational procedures adopted for RVSM are
effective and appropriate.
4. Confirm that the altitude-monitoring program is effective.
The principal purpose of this phase has been to gain confidence
that the operational trial phase can begin.
2. Operational Trial Phase
As the objectives of the system verification phase have been met,
NATSPG plans to implement RVSM at designated flight levels with
separation of 1,000 feet on an operational trial basis starting March
27, 1997 for approximately one year. In the initial phase of
implementation, the NATSPG plans to implement RVSM only at certain
flight levels (FL 330 to FL 370). The objectives of the operational
trial phase are to:
1. Continue to collect altitude-keeping performance data.
2. Increase the level of confidence that safety goals are being
met.
3. Demonstrate operationally that there are no difficulties with
RVSM implementation.
Starting March 27, 1997, aircraft that do not meet the RVSM
requirements will be excluded from operations at flight levels where
RVSM is applied. Provided that all requirements continue to be met, at
the end of the operational trial period, RVSM will be declared fully
operational.
To help operators prepare to comply with the requirements of this
rule, the FAA has prepared two documents, which are available in the
docket. The first of these documents, distributed at the ICAO meetings
since April, 1994, is Interim Guidance Material on the Approval of
Operators/Aircraft for RVSM Operations (91-RVSM). This document
contains guidance for the approval of aircraft and operators to conduct
RVSM operations. It is based on the ICAO manual on RVSM. It was
developed in the NATSPG forum by technical and operational experts from
the FAA, the European Joint Airworthiness Authorities (JAA), the
aircraft manufacturers, and pilot associations. The FAA is taking steps
to publish it as an advisory circular (AC). In the interim, a copy of
91-RVSM may be obtained by contacting the person identified under FOR
FURTHER INFORMATION CONTACT.
The second document is a Flight Standards Handbook Bulletin (HBAT)
97-02 entitled Approval of Aircraft and Operators for Flight in
Airspace Above Flight Level 290 Where 1,000 Foot Vertical Separation
Minimum Is Applied, and has been distributed through Flight Standards
offices.
The interim guidance material describes methods of complying with
the airworthiness approval, maintenance program approval, and
operations approval requirements in the rule. It discusses timing,
process, and maintenance and operations material that the operator
should submit for FAA review and evaluation normally at least 60 days
before the planned operation in RVSM airspace. Operators under Title
14, Code of Federal Regulations (14 CFR) part 91 receive FAA approval
in the form of a letter of authorization, and operators under 14 CFR
parts 121, 125, and 135 receive operations specifications approval.
The HBAT contains background information on RVSM, directs
inspectors to use the Interim Guidance 91-RVSM for operator approval,
and contains specific direction on issuing operating authority.
Altitude-Keeping Performance
The FAA, in conjunction with the NATSPG, also has been monitoring
aircraft altitude-keeping performance. The NATSPG, with industry
participation, determined that the overall (i.e., accounting for
equipment and human error) criterion for safety in the NAT region is
the target level of safety (TLS) of no more than five fatal accidents
in 1 billion flying hours. The FAA has determined that the appropriate
method of assessing collision risk is the Reich collision risk model
(CRM). As noted in AC No. 91-70, ``Oceanic Operations,'' collision risk
refers to the number of midair accidents likely to occur due to loss of
separation in a prescribed volume of airspace for a specific number of
flight hours.
To ensure that the TLS considered acceptable in the NAT is met, the
FAA and the NATSPG are monitoring the total vertical error (TVE) and
the remaining CRM parameters that are critical for safety assessment
(probability of lateral and longitudinal overlap). TVE is defined as
the geometric difference between aircraft and flight level altitude. To
monitor TVE, the FAA and the NATSPG have deployed measurement systems
that will produce estimates of aircraft and flight level geometric
altitude. The overall goal of monitoring is to ensure that
airworthiness, maintenance, and operational approval requirements
result in required system performance (and level of safety) in the
flight environment on a continuing basis. Currently, two altitude-
monitoring
[[Page 17484]]
systems are operating: a Global Positioning System (GPS)-based
monitoring system and a Height monitoring unit (HMU) that uses a Mode C
multilateration system. Data are currently being collected on both
systems to determine technical and operational feasibility.
Collision Risk Methodology (CRM) (including an acceptable level of
safety) was used to develop the requirements for safe implementation of
a 1,000 foot vertical separation standard. The level of safety was
developed using historical data on safety from global sources. One
precedence used was a period of 100 to 150 years between midair
collisions. When the NATSPG TLS of 5 accidents in a billion flying
hours is projected in terms of a calendar year interval between
accidents, it yields a theoretical interval of approximately 390 years
between midair collisions. The accepted level of safety is consistent
with the acceptable level for aircraft hull loss and is based on the
precedence of extremely improbable events as they relate to system
safety, the basis for certain requirements in certification regulations
such as 14 CFR 25.1309. The United States supported the methodology
used to derive the accepted level of safety for RVSM implementation.
Following the development of the accepted level of safety, the
corresponding limits for TVE and altimetry system errors were
developed. A detailed discussion of the mathematical rationale leading
to the requirements for safe implementation of RVSM is available in the
docket.
Current Requirements
In the Federal Aviation Regulations, 14 CFR 91.179(b)(3)
establishes the 2,000 ft minimum separation in domestic airspace by
requiring that flights in uncontrolled airspace at and above FL 290 on
easterly magnetic courses (zero degrees through 179 degrees) be
conducted at 4,000 ft intervals, starting at FL 290, (e.g., FL 290,
330, or 370). West-bound flights (magnetic courses of 180 degrees
through 359 degrees) must be conducted at 4,000 ft intervals beginning
at FL 310 (e.g., FL 310, 350, or 390). Flights in controlled airspace
must be conducted at an altitude assigned by ATC.
For operations within a foreign country, 14 CFR 91.703 requires
compliance with that country's regulations. For operations over the
high seas outside the United States, 14 CFR 91.703 requires that
aircraft of U.S. registry comply with Annex 2 (Rules of the Air) to the
Convention on International Civil Aviation. Annex 2, amendment 32,
effective February 19, 1996, reflects the planned change from 2,000
feet to 1,000 feet vertical separation for Instrument Flight Rules
(IFR) traffic between FL 290 and FL 410, based on appropriate airspace
designation, international agreements, and conformance with specified
conditions. By this amendment, Annex 2, through amendment 32, is
incorporated by reference in Sec. 91.703(b).
Regulatory requirements for operations within the NAT MNPS by U.S.-
registered aircraft are contained in 14 CFR 91.705. The regulation
states that the aircraft must have approved navigation performance
capability that meets specified requirements, and that the operator
have authorization from the Administrator for operations in the NAT
MNPS.
The NAT MNPS is addressed in greater detail in appendix C to Part
91, Operations in the North Atlantic (NAT) Minimum Navigation
Performance Specifications (MNPS) Airspace. The appendix defines the
airspace geographically and sets minimum navigation performance
capability requirements.
General Discussion of the Amendment
This rule allows operations of civil aircraft of U.S. registration
outside the U.S. in airspace where a 1,000 foot vertical separation is
applied, based on improvements in altitude-keeping technology. These
improvements include:
Introduction of the air data computer (ADC), which
provides an automatic means of correcting the known static source error
of aircraft to improve aircraft altitude measurement capability.
Development of altimeters with enhanced transducers or
double aneroids for computing altitude.
Under this amendment, airspace or routes in which RVSM is applied
are considered special qualification airspace. Both the operator and
the specific types of aircraft that the operator intends to use in RVSM
airspace would have to be approved by the appropriate FAA office before
the operator conducts flights in RVSM airspace.
Implementation of a 1,000 foot vertical separation standard above
FL 290 offers substantial operational benefits to operators, including:
Greater availability of the most fuel-efficient altitudes.
In the RVSM environment, aircraft are able to fly closer to their
optimum altitude at initial level off and through step climbing to the
optimum altitude during the enroute phase.
Greater availability of the most time- and fuel-efficient
tracks and routes (and an increased probability of obtaining these
tracks and routes). Operators often are not cleared on the track or
route that was filed due to demand for the optimum routes, and
resultant traffic congestion on those routes. RVSM allows ATC to
accommodate a greater number of aircraft on a given track or route.
More time- and fuel-efficient tracks or routes would therefore be
available to more aircraft.
Increased controller flexibility. RVSM gives ATC greater
flexibility to manage traffic by increasing the number of flight levels
on each track or route.
Enhanced safety in the lateral dimension. Studies indicate
that RVSM produces a wider distribution of aircraft among different
tracks and altitudes, resulting in less exposure to aircraft at
adjacent separation standards. RVSM reduces the number of occasions
when two aircraft pass each other separated by a single separation
standard (e.g., 60 nm laterally). The benefit to safety is that, should
an aircraft enter, as a result of gross navigation error, onto an
adjacent track, and another aircraft is on that track, there is an
increased probability that the two aircraft would be flying at
different flight levels.
This rule amends Sec. 91.703(a)(4) and continues to require that
operations conducted within airspace designated as MNPS airspace be
conducted in accordance with Sec. 91.705. The rule also requires that
operations conducted within airspace designated as Reduced Vertical
Separation Airspace be conducted in accordance with a new Sec. 91.706.
Section 91.705 has been edited to delete references to the North
Atlantic. The revised section also corrects format errors.
Section 91.706 is added to prescribe the requirements for
operations conducted in airspace designated as Reduced Vertical
Separation Minimum Airspace. That section is similar in form to
Sec. 91.705. It requires that each operator obtain authorization from
the FAA to operate in airspace designated as RVSM, and requires each
operator to obtain RVSM approval for their aircraft in accordance with
appendix G.
The new appendix G specifies essential aircraft equipment and
capabilities, including altitude measurement systems; altitude control
systems; and an altitude alert system. RVSM aircraft are required to
meet requirements for altimetry system error containment, equipment
installation, and equipment tolerances. The control systems are
required to automatically
[[Page 17485]]
control aircraft altitude to within specified limits (in non-turbulent,
non-gust conditions). The associated alert systems are required to
alert flightcrews to deviations of more than 300 feet from selected
altitudes, or 200 feet for aircraft for which application for type
certification occurs after April 8, 1997.
Altitude system error (ASE) requirements are prescribed in part 91,
appendix G, section 2, paragraph (e). The ASE that aircraft groups are
required to exhibit in service for acceptable aircraft altitude-keeping
performance to be achieved in the full RVSM flight envelope is:
The mean ASE of an aircraft group must not exceed 120 feet and the
sum of mean ASE plus three standard deviations of ASE must not exceed
245 feet.
On the basis of studies documented in ICAO Document 9536, Volume 2,
a margin was established between the ASE to be exhibited in service and
the ASE criteria used for initial approval to allow for some
degradation with increasing aircraft age. Thus, for initial aircraft
approval, the following ASE requirements are established in the basic
envelope (as defined below):
The mean ASE of the group must not exceed 80 feet, and the sum of
ASE for the aircraft group plus three standard deviations must not
exceed 200 feet.
For the purpose of approving in-service aircraft, the FAA divides
the flight envelope into two parts to provide a reasonable method for
applying the above criteria to currently type-certificated aircraft.
The Basic RVSM flight envelope (see part 91, appendix G, section 1)
represents the aircraft speeds, altitudes and weights at which the
majority of aircraft operations are conducted. The Full RVSM flight
envelope also includes portions of the operating flight envelope in
which aircraft operate less frequently. The values of 80 feet for mean
ASE and 200 feet for mean ASE plus three standard deviations of ASE
must be met in the Basic RVSM flight envelope. The values of 120 feet
for mean ASE and 245 feet for mean ASE plus three standard deviations
must be met in the Full RVSM flight envelope.
For RVSM approval of aircraft for which a type certificate is
requested after April 9, 1997, however, the FAA has determined that it
is not necessary to continue designating two flight envelopes (i.e.,
Basic and Full flight envelopes). With values of 80 feet for mean ASE
and 200 feet for mean ASE plus three standard deviations for ASE
established during the design phase, the FAA has determined that those
values can also be achieved throughout the Full RVSM flight envelope.
The ASE criteria for group aircraft will not be applied to non-
group aircraft, because with non-group aircraft there is no data with
which to measure airframe to airframe variability. Therefore, a single
ASE value would be established to control the simple sum of altimetry
errors. To control the overall population distribution, this limit
would be set at a value less than that for group aircraft.
The new appendix G also provides for limited deviations to the
operator and aircraft approval requirements. To accomplish this, the
appendix states that an operator's request should normally be submitted
at least 48 hours in advance of the proposed flight except under
mitigating circumstances, so that ATC could then determine if proper
separation could be provided without interference with normal RVSM
operations. As with current appendix C to part 91, such deviations are
considered as exceptions, not normal operations. For example, the
operations envisioned that could be conducted in deviation from the
RVSM requirements are the occasional part 91 flight in a business jet,
or a maintenance ferry flight of a part 121 certificate holder's
aircraft for the purpose of performing maintenance and returning the
aircraft to RVSM-approved status.
Under this amendment, the new appendix G designates, in Section 8,
those areas in which RVSM may be applied. Initially, as previously
stated, RVSM will be applied only at designated flight levels in NAT
MNPS airspace (e.g., FL 330 to FL 370). However, the appendix is
otherwise structured in a generic format so that other airspace could
be added to the designation when RVSM is expanded. By reviewing Section
8, operators are provided notification of areas where RVSM may be
applied. (Operations still have the Annex 2 requirements to determine
route requirements during preflight.)
NATSPG has agreed to change the floor and ceiling of MNPS airspace
to FL 285 and FL 420. This change will enable the application of RVSM
between FL 290 and FL 410, inclusive. The FAA does not consider this to
be a substantive change.
The new appendix generally defines RVSM airspace as any airspace
between FL 290 and FL 410 (inclusive) where aircraft are to be
separated by a minimum of 1,000 feet vertically. The appendix also
specifies that operators receive approval for RVSM operations either
through operations specifications or a Letter of Authorization, as
appropriate. Applicants for operation in RVSM airspace are required to
submit supporting material for aircraft approval, including information
on compliance with the performance and hardware requirements and on the
operator's maintenance program, in connection with meeting RVSM minimum
performance requirements. Operators are also required to implement
policies and procedures related to RVSM operations and to show that
their pilots have necessary knowledge of those policies and procedures.
Specific guidance on how to meet the requirements is available in
Interim Guidance Material 91-RVSM, which addresses various aspects of
RVSM requirements, including maintenance and operations programs.
Operators can obtain authorization for RVSM from their local Flight
Standards District Office (FSDO) or Certificate Management Office.
Approval of aircraft may be given for aircraft groups or for individual
aircraft. In the former case, the FAA expects that operators would need
to enlist the assistance of the aircraft manufacturers to develop the
necessary data on the aircraft group. In the latter case, the operator
would work with the FAA to determine the accuracy of the altitude-
keeping equipment on the individual aircraft.
This amendment results in more stringent vertical navigation
standards in oceanic airspace; the standards will be applied in other
airspace above FL 290 as they are designated as RVSM airspace in the
future. In NAT MNPS airspace, aircraft and operators that do not meet
the vertical navigation requirements of RVSM will be accommodated in 4
ways--First, RVSM will be implemented in stages. In Stage 1, RVSM
approval will be required when operating between FL 33 to FL 370
inclusive. Unapproved operators will have the option of flying at FL
310 and below or FL 390 and above. The staged implementation plan was
adopted to give operators more time and flexibility in their planning
to gain RVSM approval (Note: NATSPG will evaluate user needs before
implementing a second stage that applies RVSM requirements to other
flight levels.). Second, unapproved operators will be allowed to climb
or descend in MNPS airspace through flight levels where RVSM is applied
to operate at FL's where RVSM is not applied. Third, the operator may
be authorized to deviate from RVSM requirements in accordance with the
provisions of Appendix G, Section 5. Though it is not intended to be
the routine mode of operation, this section
[[Page 17486]]
does enable an operator that has not been RVSN approved (or an aircraft
with an RVSM required system temporarily inoperative) to fly in MNPS
airspace where RVSM is applied provided request is made in advance and
ATC determines that appropriate separation can be applied without
imposing a burden on other operators. And fourth, when RVSM is applied
to all flight levels in MNPS airspace (FL 290 to 410 inclusive), the
operator not wishing to gain RVSM approval will retain the option of
crossing the North Atlantic at FL's above or below airspace where RVSM
requirements apply. Such an operator will be able to fly at FL 280 and
below or FL 430 and above. The FAA has determined that these are
reasonable and adequate means to accommodate the transition to RVSM
requirements, particularly for general aviation operators.
The Interim Guidance is intended to be applicable for RVSM aircraft
and operator approval in continental, oceanic, and remote airspace. The
FAA expects that RVSM eventually will be applied in other airspace,
including the Pacific region, Europe, and eventually even U.S.
airspace. The rule establishes requirements for operation of U.S.
registered aircraft outside the U.S. in any airspace designated for
RVSM; it specifically establishes that the NAT MNPS airspace is an area
where RVSM may be applied.
Need for Immediate Adoption
This action is a product of international agreements. It is the
implementation of a joint, ongoing action started in 1988 with the
member States of ICAO. The international aviation community is prepared
to and will begin operational testing of the RVSM procedures in certain
altitudes on March 27, 1997.
The United States, as a member of ICAO, has an international
commitment to participate in this action. Arriving air traffic, having
departed Europe and separated at RVSM altitudes, as a practical matter,
cannot arrive in oceanic airspace controlled by the United States, all
needing to be reassigned to a pre-RVSM separation altitude. Unless this
rule is implemented by March 27, 1997, to avoid a significant safety
problem, there would have to be major delays for westbound NAT traffic
in airspace the FAA does not control.
Additionally, U.S. operators will incur an economic disadvantage
compared to their European competitors, if they are unable to utilize
the benefits gained from operating at RVSM altitudes beginning on March
27, 1997,
Because of the imminent beginning of operational testing by all
countries involved, good cause exists for making this final rule
effective immediately.
Regulatory Evaluation Summary
Changes to Federal regulations must undergo several economic
analyses. First, Executive Order 12866 directs that each Federal agency
shall adopt a regulation only upon a reasoned determination that the
benefits of the intended regulation justify its costs. Second, the
Regulatory Flexibility Act of 1980 requires agencies to analyze the
economic effect of regulatory changes on small entities. Third, the
Office of Management and Budget directs agencies to assess the effect
of regulatory changes on international trade. In conducting these
analyses, the FAA has determined that this rule: (1) generates benefits
that justify its costs and is not ``a significant regulatory action''
as defined in the Executive Order; (2) is significant as defined in
Department of Transportation's Regulatory Policies and Procedures; (3)
does not have a significant impact on a substantial number of small
entities; and (4) does not constitute a barrier to international trade.
These analyses, available in the docket are summarized below.
This rule establishes a new Federal Aviation Regulations (FAR)
section that allows the vertical separation minimum from 2,000 feet to
1,000 feet between FL 290 and FL 410 to be reduced in certain
designated airspace. This action is intended to increase the number of
available flight levels, enhance airspace capacity, permit operators to
fly more fuel/time efficient tracks and altitudes, and enhance air
traffic controller flexibility by increasing the number of available
flight levels, while maintaining an equivalent level of safety.
Assuming that operators with the capability of operating above FL
410 would do so in lieu of obtaining RVSM approval, the FAA estimates
that this rule costs U.S. operators $28.1 million in constant 1995
dollars for the fifteen-year time period 1996-2010 or $20.4 million
discounted. Benefits begin accruing in 1997. Benefits, based on fuel
savings for the commercial aircraft fleet over the years 1997 to 2010,
are estimated to be $35.8 million undiscounted in constant 1995 dollars
or discounted at $24.0 million. The other benefits of implementing RVSM
are: (1) availability of added tracks; (2) increased controller
flexibility to clear aircraft for efficient step (enroute) climbs; and
(3) increased controller flexibility to route aircraft to appropriate
tracks. Therefore, based on a quantitative and qualitative evaluation
of this action, the FAA believes that the amendment is cost-beneficial.
Regulatory Flexibility Act
The FAA has determined that these amendments do not significantly
affect a substantial number of small entities.
International Trade Impact Analysis
This amendment does not affect the importation of foreign products
or services into the United States or the exportation of U.S. products
or services to foreign countries.
Federalism Implications
This rule 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 amendment does not have sufficient
federalism implications to warrant the preparation of a Federalism
Assessment.
Paperwork Reduction Act of 1995
The reporting and recordkeeping requirements associated with this
rule remain the same as under the current rules and have previously
been approved by the Office of Management and Budget under the
provisions of the Paperwork Reduction Act of 1980 (Pub. L. 96-511) and
have been assigned OMB Control Numbers 2120-0026. The FAA believes that
this rule does not impose any additional recordkeeping or reporting
requirements.
Unfunded Mandates Reform Act of 1995
The FAA has determined that the requirements of Title II of the
Unfunded Mandates Reform Act of 1995 do not apply to this rulemaking.
International Civil Aviation Organization and Joint Aviation
Regulations
In keeping with U.S. obligations under the Convention on
International Civil Aviation Organization (ICAO), it is FAA policy to
comply with ICAO Standards and Recommended Practices (SARP) to maximum
extent practicable. The operator and aircraft approval process was
developed jointly by the FAA and the JAA under the auspices of NATSPG.
The FAA has determined that this amendment does not present any
difference.
[[Page 17487]]
Conclusion
For the reasons discussed in the Preamble, and based on the
findings in the Regulatory Flexibility Determination and the
International Trade Impact Analysis, the FAA has determined that this
rule is not a ``significant regulatory action'' under Executive Order
12866. In addition, the FAA certifies that this regulation does not
have a significant economic impact, positive or negative, on a
substantial number of small entities under the criteria of the
Regulatory Flexibility Act of 1990. This amendment is considered
significant under Order DOT 2100.5, Policies and Procedures for
Simplification, Analysis, and Review of Regulations due to the
significant international ramifications of this rule. A regulatory
evaluation of the regulation, including a Regulatory Flexibility
Determination and International Trade Impact Analysis, are available in
the docket. A copy may be obtained by contacting the person identified
under FOR FURTHER INFORMATION CONTACT.
List of Subjects in 14 CFR Part 91
Air-traffic control, Aircraft, Airmen, Airports, Aviation safety,
Reporting and recordkeeping requirements.
The Amendment
In consideration of the foregoing, the Federal Aviation
Administration amends part 91 of Title 14 of the Code of Federal
Regulations (14 CFR part 91) as follows:
PART 91--GENERAL OPERATING AND FLIGHT RULES
1. The authority citation for Part 91 continues to read as follows:
Authority: 49 U.S.C. 106(g), 40103, 40113, 40120, 44101, 44111,
44701, 44709, 44711, 44712, 44715, 44716, 44717, 44722, 46306,
46315, 46316, 46502, 46504, 46506-46507, 47122, 47508, 47528-47531.
2. Section 91.703 is amended by revising paragraphs (a)(4) and (b)
to read as follows:
Sec. 91.703 Operations of civil aircraft of U.S. registry outside of
the United States.
(a)* * *
(4) When operating within airspace designated as Minimum Navigation
Performance Specifications (MNPS) airspace, comply with Sec. 91.705.
When operating within airspace designated as Reduced Vertical
Separation Minimum (RVSM) airspace, comply with Sec. 91.706.
(b) Annex 2 to the Convention on International Civil Aviation,
Ninth Edition--July 1990, with Amendments through Amendment 32
effective February 19, 1996, to which reference is made in this part,
is incorporated into this part and made a part hereof as provided in 5
U.S.C. Sec. 552 and pursuant to 1 CFR part 51. Annex 2 (including a
complete historic file of changes thereto) is available for public
inspection at the Rules Docket, AGC-200, Federal Aviation
Administration, 800 Independence Avenue SW., Washington, DC 20591; or
at the Office of the Federal Register, 800 North Capitol Street, NW.,
Suite 700, Washington, DC. In addition, Annex 2 may be purchased from
the International Civil Aviation Organization (Attention: Distribution
Officer), P.O. Box 400, Succursale, Place de L'Aviation Internationale,
1000 Sherbrooke Street West, Montreal, Quebec, Canada H3A 2R2.
3. Section 91.705 is revised to read as follows:
Sec. 91.705 Operations within airspace designated as Minimum
Navigation Performance Specification Airspace.
(a) Except as provided in paragraph (b) of this section, no person
may operate a civil aircraft of U.S. registry in airspace designated as
Minimum Navigation Performance Specifications airspace unless--
(1) The aircraft has approved navigation performance capability
that complies with the requirements of appendix C of this part; and
(2) The operator is authorized by the Administrator to perform such
operations.
(b) The Administrator may authorize a deviation from the
requirements of this section in accordance with Section 3 of appendix C
to this part.
4. New Sec. 91.706 is added to read as follows:
Sec. 91.706 Operations within airspace designed as Reduced Vertical
Separation Minimum Airspace.
(a) Except as provided in paragraph (b) of this section, no person
may operate a civil aircraft of U.S. registry in airspace designated as
Reduced Vertical Separation Minimum (RVSM) airspace unless:
(1) The operator and the operator's aircraft comply with the
requirements of appendix G of this part; and
(2) The operator is authorized by the Administrator to conduct such
operations.
(b) The Administrator may authorize a deviation from the
requirements of this section in accordance with Section 5 of appendix G
to this part.
5. Section 1 of Appendix C to Part 91 is amended by removing the
flight levels ``FL 275'' and ``FL 400'' cited in the first sentence and
replacing them with ``FL 285'' ``FL 420'' respectively.
6. A new appendix G is added to read as follows:
Appendix G to Part 91--Operations in Reduced Vertical Separation
Minimum (RVSM) Airspace
Section 1. Definitions
Reduced Vertical Separation Minimum (RVSM) Airspace. Within RVSM
airspace, air traffic control (ATC) separates aircraft by a minimum
of 1,000 feet vertically between flight level (FL) 290 and FL 410
inclusive. RVSM airspace is special qualification airspace; the
operator and the aircraft used by the operator must be approved by
the Administrator. Air-traffic control notifies operators of RVSM by
providing route planing information. Section 8 of this appendix
identifies airspace where RVSM may be applied.
RVSM Group Aircraft. Aircraft within a group of aircraft,
approved as a group by the Administrator, in which each of the
aircraft satisfy each of the following:
(a) The aircraft have been manufactured to the same design, and
have been approved under the same type certificate, amended type
certificate, or supplemental type certificate.
(b) The static system of each aircraft is installed in a manner
and position that is the same as those of the other aircraft in the
group. The same static source error correction is incorporated in
each aircraft of the group.
(c) The avionics units installed in each aircraft to meet the
minimum RVSM equipment requirements of this appendix are:
(1) Manufactured to the same manufacturer specification and have
the same part number; or
(2) Of a different manufacturer or part number, if the applicant
demonstrates that the equipment provides equivalent system
performance.
RVSM Nongroup Aircraft. An aircraft that is approved for RVSM
operations as an individual aircraft.
RVSM Flight envelope. An RVSM flight envelope includes the range
of Mach number, weight divided by atmospheric pressure ratio, and
altitudes over which an aircraft is approved to be operated in
cruising flight within RVSM airspace. RVSM flight envelopes are
defined as follows:
(a) The full RVSM flight envelope is bounded as follows:
(1) The altitude flight envelope extends from FL 290 upward to
the lowest altitude of the following:
(i) FL 410 (the RVSM altitude limit);
(ii) The maximum certificated altitude for the aircraft; or
(iii) The altitude limited by cruise thrust, buffet, or other
flight limitations.
(2) The airspeed flight envelope extends:
(i) From the airspeed of the slats/flaps-up maximum endurance
(holding) airspeed, or the maneuvering airspeed, whichever is lower;
(ii) To the maximum operating airspeed (Vmo/Mmo), or
airspeed limited by cruise thrust buffet, or other flight
limitations, whichever is lower.
[[Page 17488]]
(3) All permissible gross weights within the flight envelopes
defined in paragraphs (1) and (2) of this definition.
(b) The basic RVSM flight envelope is the same as the full RVSM
flight envelope except that the airspeed flight envelope extends:
(1) From the airspeed of the slats/flaps-up maximum endurance
(holding) airspeed, or the maneuver airspeed, whichever is lower;
(2) To the upper Mach/airspeed boundary defined for the full
RVSM flight envelope, or a specified lower value not less than the
long-range cruise Mach number plus .04 Mach, unless further limited
by available cruise thrust, buffet, or other flight limitations.
Section 2. Aircraft Approval
(a) An operator may be authorized to conduct RVSM operations if
the Administrator finds that its aircraft comply with this section.
(b) The applicant for authorization shall submit the appropriate
data package for aircraft approval. The package must consist of at
least the following:
(1) An identification of the RVSM aircraft group or the nongroup
aircraft;
(2) A definition of the RVSM flight envelopes applicable to the
subject aircraft;
(3) Documentation that establishes compliance with the
applicable RVSM aircraft requirements of this section; and
(4) The conformity tests used to ensure that aircraft approved
with the data package meet the RVSM aircraft requirements.
(c) Altitude-keeping equipment: All aircraft. To approve an
aircraft group or a nongroup aircraft, the Administrator must find
that the aircraft meets the following requirements:
(1) The aircraft must be equipped with two operational
independent altitude measurement systems.
(2) The aircraft must be equipped with at least one automatic
altitude control system that controls the aircraft altitude--
(i) Within a tolerance band of 65 feet about an
acquired altitude when the aircraft is operated in straight and
level flight under nonturbulent, nongust conditions; or
(ii) Within a tolerance band of 130 feet under
nonturbulent, nongust conditions for aircraft for which application
for type certification occurred on or before April 9, 1997 that are
equipped with an automatic altitude control system with flight
management/performance system inputs.
(3) The aircraft must be equipped with an altitude alert system
that signals an alert when the altitude displayed to the flight crew
deviates from the selected altitude by more than:
(i) 300 feet for aircraft for which application for
type certification was made on or before April 9, 1997; or
(ii) 200 feet for aircraft for which application for
type certification is made after April 9, 1997.
(d) Altimetry system error containment: Group aircraft for which
application for type certification was made on or before April 9,
1997. To approve group aircraft for which application for type
certification was made on or before April 9, 1997, the Administrator
must find that the altimetry system error (ASE) is contained as
follows:
(1) At the point in the basic RVSM flight envelope where mean
ASE reaches its largest absolute value, the absolute value may not
exceed 80 feet.
(2) At the point in the basic RVSM flight envelope where mean
ASE plus three standard deviations reaches its largest absolute
value, the absolute value may not exceed 200 feet.
(3) At the point in the full RVSM flight envelope where mean ASE
reaches its largest absolute value, the absolute value may not
exceed 120 feet.
(4) At the point in the full RVSM flight envelope where mean ASE
plus three standard deviations reaches its largest absolute value,
the absolute value may not exceed 245 feet.
(5) Necessary operating restrictions. If the applicant
demonstrates that its aircraft otherwise comply with the ASE
containment requirements, the Administrator may establish an
operating restriction on that applicant's aircraft to restrict the
aircraft from operating in areas of the basic RVSM flight envelope
where the absolute value of mean ASE exceeds 80 feet, and/or the
absolute value of mean ASE plus three standard deviations exceeds
200 feet; or from operating in areas of the full RVSM flight
envelope where the absolute value of the mean ASE exceeds 120 feet
and/or the absolute value of the mean ASE plus three standard
deviations exceeds 245 feet.
(e) Altimetry system error containment: Group aircraft for which
application for type certification is made after April 9, 1997. To
approve group aircraft for which application for type certification
is made after April 9, 1997, the Administrator must find that the
altimetry system error (ASE) is contained as follows:
(1) At the point in the full RVSM flight envelope where mean ASE
reaches its largest absolute value, the absolute value may not
exceed 80 feet.
(2) At the point in the full RVSM flight envelope where mean ASE
plus three standard deviations reaches its largest absolute value,
the absolute value may not exceed 200 feet.
(f) Altimetry system error containment: Nongroup aircraft. To
approve a nongroup aircraft, the Administrator must find that the
altimetry system error (ASE) is contained as follows:
(1) For each condition in the basic RVSM flight envelope, the
largest combined absolute value for residual static source error
plus the avionics error may not exceed 160 feet.
(2) For each condition in the full RVSM flight envelope, the
largest combined absolute value for residual static source error
plus the avionics error may not exceed 200 feet.
(g) If the Administrator finds that the applicant's aircraft
comply with this section, the Administrator notifies the applicant
in writing.
Section 3. Operator Authorization
(a) Authority for an operator to conduct flight in airspace
where RVSM is applied is issued in operations specifications or a
Letter of Authorization, as appropriate. To issue an RVSM
authorization, the Administrator must find that the operator's
aircraft have been approved in accordance with Section 2 of this
appendix and that the operator complies with this section.
(b) An applicant for authorization to operate within RVSM
airspace shall apply in a form and manner prescribed by the
Administrator. The application must include the following:
(1) An approved RVSM maintenance program outlining procedures to
maintain RVSM aircraft in accordance with the requirements of this
appendix. Each program must contain the following:
(i) Periodic inspections, functional flight tests, and
maintenance and inspection procedures, with acceptable maintenance
practices, for ensuring continued compliance with the RVSM aircraft
requirements.
(ii) A quality assurance program for ensuring continuing
accuracy and reliability of test equipment used for testing aircraft
to determine compliance with the RVSM aircraft requirements.
(iii) Procedures for returning noncompliant aircraft to service.
(2) For an applicant who operates under part 121 or 135, initial
and recurring pilot training requirements.
(3) Policies and Procedures. An applicant who operates under
part 121 or 135 shall submit RVSM policies and procedures that will
enable it to conduct RVSM operations safely.
(c) Validation and Demonstration. In a manner prescribed by the
Administrator, the operator must provide evidence that:
(1) It is capable to operate and maintain each aircraft or
aircraft group for which it applies for approval to operate in RVSM
airspace; and
(2) Each pilot has an adequate knowledge of RVSM requirements,
policies, and procedures.
Section 4. RVSM Operations
(a) Each person requesting a clearance to operate within RVSM
airspace shall correctly annotate the flight plan filed with air
traffic control with the status of the operator and aircraft with
regard to RVSM approval. Each operator shall verify RVSM
applicability for the flight planned route through the appropriate
flight planning information sources.
(b) No person may show, on the flight plan filed with air
traffic control, an operator or aircraft as approved for RVSM
operations, or operate on a route or in an area where RVSM approval
is required, unless:
(1) The operator is authorized by the Administrator to perform
such operations; and
(2) The aircraft has been approved and complies with the
requirements of Section 2 of this appendix.
Section 5. Deviation Authority Approval
The Administrator may authorize an aircraft operator to deviate
from the requirements of Sec. 91.706 for a specific flight in RVSM
airspace if that operator has not been approved in accordance with
Section 3 of this appendix, and if:
(2) The operator submits an appropriate request with the air
traffic control center
[[Page 17489]]
controlling the airspace, (request should be made at least 48 hours
in advance of the operation unless prevented by exceptional
circumstances); and
(b) At the time of filing the flight plan for that flight, ATC
determines that the aircraft may be provided appropriate separation
and that the flight will not interfere with, or impose a burden on,
the operations of operators who have been approved for RVSM
operations in accordance with Section 3 of this appendix.
Section 6. Reporting Altitude-Keeping Errors
Each operator shall report to the Administrator each event in
which the operator's aircraft has exhibited the following altitude-
keeping performance:
(a) Total vertical error of 300 feet or more;
(b) Altimetry system error of 245 feet or more; or
(c) Assigned altitude deviation of 300 feet or more.
Section 7. Removal or Amendment of Authority
The Administrator may amend operations specifications to revoke
or restrict an RVSM authorization, or may revoke or restrict an RVSM
letter of authorization, if the Administrator determines that the
operator is not complying, or is unable to comply, with this
appendix or subpart H of this part. Examples of reasons for
amendment, revocation, or restriction include, but are not limited
to, an operator's:
(a) Committing one or more altitude-keeping errors in RVSM
airspace;
(b) Failing to make an effective and timely response to identify
and correct an altitude-keeping error; or
(c) Failing to report an altitude-keeping error.
Section 8. Airspace Designation
RVSM may be applied in the following ICAO Flight Information
Regions (FIR's): New York Oceanic, Gander Oceanic, Sondrestrom FIR,
Reykjavik Oceanic, Shanwick Oceanic, and Santa Maria Oceanic.
RVSM may be effective in the Minimum Navigation Performance
Specification (MNPS) airspace with the NAT. The MNPS airspace within
the NAT is defined by the volume of airspace FL 285 and FL 420
extending between latitude 27 degrees north and the North Pole,
bounded in the east by the eastern boundaries of control areas Santa
Maria Oceanic, Shanwick Oceanic, and Reykjavik Oceanic and in the
west by the western boundaries of control areas Reykjavik Oceanic,
Gander Oceanic, and New York Oceanic, excluding the areas west of 60
degrees west and south of 38 degrees 30 minutes north.
Issued in Washington, DC, on March 27, 1997.
Barry L. Valentine,
Acting Administrator.
[FR Doc. 97-8367 Filed 4-8-97; 8:45 am]
BILLING CODE 4910-13-M