RVSM Training Booklet
ACAS Airborne Collision Avoidance System
ACC Area Control Centre
ACH ATC Flight Plan Change Message
ACI Area of Common Interest
ACT Activation Message (OLDI)
ADEP Aerodrome of Departure
ADES Aerodrome of Destination
AFIL Flight Plan Filed in the Air
AFP ATC Flight Plan Proposal Message
AIC Aeronautical Information Circular
AIP Aeronautical Information Publication
AMC Airspace Management Cell
ANT Airspace and Navigation Team
APDSG ATM Procedures Development Sub-Group
APL ATC Flight Plan Message (IFPS)
ASE Altimetry System Error
ATC Air Traffic Control
ATM Air Traffic Management
ATS Air Traffic Service
CDB Central Data Base
CFL Cleared Flight Level
CFMU Central Flow Management Unit
CVSM Conventional Vertical Separation Minimum
EANPG European Air Navigation Planning Group
EATCHIP European Air Traffic Control Harmonisation and Integration Program
ECAC European Civil Aviation Conference
FAA Federal Aviation Administration (USA)
FDPS Flight Data Processing System
FIR Flight Information Region
FL Flight Level
FLAS Flight Level Allocation Scheme
FMP Flow Management Position (ACC)
FPL Flight Plan
GAT General Air Traffic
GMU GPS Height Monitoring Unit
GPS Global Positioning System
HMU Height Monitoring Unit
ICAO International Civil Aviation Organization
IFPS Integrated Initial Flight Plan Processing System
IFPZ IFPS Zone
IFR Instrument Flight Rules
JAA Joint Aviation Authorities
JAA AMC JAA Acceptable Means of Compliance
JAR Joint Aviation Requirements
RFL Requested Flight Level
RGCSP Review of the General Concept of Separation Panel
RNAV Area Navigation
RNP Required Navigation Performance
RPL Repetitive Flight Plan
RVSM Reduced Vertical Separation Minimum of 300 m /1 000 ft Between FL 290 and FL 410 Inclusive
SARPs Standards and Recommended Practices
SDB State Data Base
SSEC Static Source Error Correction
SSR Secondary Surveillance Radar
STCA Short Term Conflict Alert
TA Traffic Advisory (ACAS)
TGL Temporary Guidance Leaflet (JAA)
TLS Target Level of Safety
TSA Temporary Segregated Area
TSE Total System Error
TVE Total Vertical Error
UAC Upper Area Control Centre
UIR Upper Flight Information Region
VFR Visual Flight Rules
VSM Vertical Separation Minimum
LoA Letter of Agreement
MASPS Minimum Aircraft System Performance Specification
MNPS Minimum Navigation Performance Specification
MTCD Medium Term Conflict Detection
NAT North Atlantic
NAT CMA North Atlantic Region Central Monitoring Agency
NATSPG North Atlantic Systems Planning Group
NOTAM Notice to Airmen
OAT Operational Air Traffic
OLDI On-Line Data Interchange
RA Resolution Advisory (ACAS)
REJ Reject message (IFPS)
In the late 1970s, faced with rising fuel costs and growing demands for a more efficient use of the available airspace, the International Civil Aviation Organization (ICAO) initiated a comprehensive programme of studies to examine the feasibility of reducing the 2000 ft Vertical Separation Minimum (VSM) applied above FL 290, to the 1000 ft VSM used below FL 290. Throughout the 1980s, various studies were conducted, under the auspices of ICAO, in Canada, Europe, Japan, and the USA.
The underlyning approach of the programmes was to:
· determine the height keeping accuracy of the altimetry systems of the then current aircraft population;
· establish the causes of observed height keeping errors;
· determine the required safety levels for the implementation and use of a Reduced Vertical Separation Minimum of 1000 ft at/above FL 290;
· define a Minimum Aircraft System Performance Specification (MASPS) - for aircraft altimetry and associated height keeping equipment - which would improve height keeping accuracy to a standard compatible with the agreed safety requirements for RVSM;
· determine whether the global implementation and use of RVSM was :
1. technically feasible, subject to the overriding need to satisfy the agreed safety standards; and
2. cost beneficial.
The results of these exhaustive studies demonstrated that the global reduction of vertical separation was safe, feasible - without the imposition of unduly demanding technical requirements, and cost beneficial.
The studies also showed that the types of aircraft and the essentially unidirectional tidal flow of traffic in the North Atlantic (NAT) Minimum Navigation Performance Specification (MNPS) airspace made this Region an ideal candidate for the first implementation of RVSM.
Planning for RVSM in the NAT Region commenced in 1990. The first stage of the Operational Evaluation phase, using the 1000 ft RVSM, began on the 27th March 1997 at and between FL 330 and FL 370 inclusive. A second stage will extend the use of RVSM to between FL 310 and FL 390 inclusive, in October 1998.
From the outset it was clear that the complex nature of the European Air Traffic Services route structure, characterised by its wide variety of aircraft types, high traffic density and the high percentage of climbing and descending aircraft, would be a more demanding environment than the NAT Region for the implementation of RVSM. Thus safety considerations were given a high priority in the initial ECAC RVSM feasibility studies, which were conducted under the auspices of the EUROCONTROL Airspace and Navigation Team (ANT). These studies indicated that, subject to aircraft meeting the technical requirements set out in the MASPS, RVSM could be introduced into the European Region without prejudice to the required safety standards, and also that it would provide a positive benefit to cost ratio over a wide range of assumptions regarding future developments within the European aviation environment.
Over the last five years the improvements brought about by the EUROCONTROL European Air Traffic Control Harmonisation and Integration Program (EATCHIP) have contained the duration, and frequency of occurrence, of ATC delays despite a yearly traffic increase of between 3 to 10%.
However current forecasts indicate that air traffic movements will continue to rise, and will more than double by 2015 compared to 1996 figures. The anticipated trends are illustrated below:
It is accepted that major changes to the Air Traffic Management (ATM) systems will be necessary in order to cope with this continued traffic growth. Of the various measures under consideration, the application of RVSM is considered to be the most cost-effective means of meeting this need.
RVSM will provide six additional flight levels for use in the highly congested airspace between FL 290 to FL 410 inclusive, resulting in the following benefits:
The availability of the additional flight levels in this altitude band will allow Operators to plan for, and operate at or closer to, the optimum vertical route profile for the particular aircraft type. This will provide fuel economies in terms of both the fuel carried, and the fuel burn, for the flight. The economies are estimated at between 0.5% and 1% of the total fuel burn.
A series of ATC Real Time Simulations carried out at the EUROCONTROL Experimental Centre (EEC) at Bretigny have provided evidence that RVSM can reduce controller workload. With the same sectorisation and traffic flow, controller workload in an RVSM environment would not reach today's levels until an increase in traffic growth of around 20% had been experienced. There is also potential for further growth, through a revised airspace structure including, for example, the introduction of additional sectors.
The presence of non-RVSM approved State aircraft flying along the route network is likely to decrease the expected capacity gains.
A Cost Benefit Assessment (CBA) of the implementation of RVSM in the European RVSM Area was conducted by first establishing a "do nothing" baseline whereby only the capacity gains derived from existing approved EATCHIP Programs are achieved. In this situation the anticipated traffic growth would ultimately exceed capacity and delays and congestion, and the consequent financial penalties would become increasingly severe over time. The additional capacity, which will result from the implementation of RVSM, could significantly reduce these delays and hence generate large benefits.
Assumptions regarding the anticipated traffic growth rates used in the CBA varied from 1.9% (Low) to 3.1% (Medium) to 3.8 % (High). The use of midrange values indicated that the implementation of RVSM would provide a Benefit to Cost ratio of 11:1 over the period 1997 to 2016. As current European traffic growth rates are at the high end of the above range, and are expected to remain so over the next decade, there is every expectation that the quoted benefit to cost ratio can be achieved.
The safety standards appropriate to operations in an European RVSM environment have been derived from those developed by the ICAO Review of the General Concept of Separation Panel (RGCSP) in which the agreed tolerable level of risk is defined as a Target Level of Safety (TLS) which is expressed in terms of fatal accidents per aircraft flight hour. Based upon TLS values derived in the 1970s in the establishment of route spacing, and taking into account the subsequent increases in traffic, the RGCSP adopted a TLS of 2.5 x 10-9 fatal accidents per aircraft flight hour as a consequence of technical (altimetry) errors, for the implementation of RVSM. This TLS was used as the basis of the development of the Global RVSM MASPS.
In determining whether or not the proposed operations in RVSM airspace can meet the TLS, it is necessary to estimate the risk of a collision, in the vertical plane, in that environment. This is done by modelling the operational characteristics of the particular airspace together with the navigation performance and the physical dimensions associated with the expected aircraft population.
This is based on the Reich Collision Risk Model (CRM) shown diagramatically in figure 2. The output provides an estimate of the level of risk of a mid-air collision as a consequence of a failure of some element of the airspace system. In the RVSM case, the failure would be the loss of vertical separation as a result of a technical error. The key parameters in the modelling of RVSM operations are:
· the height keeping accuracy of the aircraft population;
· the aircraft passing frequency - which is a means of quantifying the traffic density of the given airspace;
· the lateral track keeping accuracy of the aircraft population.
Note 1: As track keeping accuracy improves, the risk of collision in the vertical plane between aircraft following the same track increases, and this places increased demands upon the vertical performance.
Note 2: In the European Region, a modified version of the Reich CRM will be used. This will combine the passing frequency and track keeping accuracy parameters into a
"Lateral Plan Overlaps per Aircraft Flight Hour "parameter. This is necessary because of the amount of crossing traffic experienced in Europe.
In the planning for RVSM operations in the NAT Region, the North Atlantic Systems Planning Group (NATSPG) adopted the RGCSP recommendations but also decided to increase the scope of the TLS to include an allowance for the risk of a mid-air collision as a consequence of a height deviation caused by "operational errors". Thus a further risk budget of 2.5 x 10-9 fatal accidents per aircraft flight hour was added to give an overall TLS of 5 x 10-9 fatal acci dents per aircraft flight hour relating to all possible causes of height deviation.The overall TLS, and the underlying philosophy was approved by the ANT for application in the European RVSM Airspace.
The assessment of the system safety confirmed that, taking due account of the expected growth of traffic in the European Airspace, a 300m (1000 ft) VSM was technically feasible, subject to:
· the mandatory carriage of the altimetry and height keeping systems, which comply with the MASPS, by all aircraft operating in the RVSM airspace;
· new operational procedures; and
· the establishment of a comprehensive means of monitoring the safe operation of the system.
The Program consists of a series of coordinated activities, performed within the EUROCONTROL Agency, ICAO, JAA, Participating States and User Organisations.
To-date the program has followed the general strategy set out in the ICAO Doc. 9574 - Manual on the Implementation of RVSM, which proposed a multi-step approach within four distinct phases:
Phase 1: Initial Planning
· Step 1: Assessment of System Safety
· Step 2: Assessment of Costs and Benefits from RVSM
· Step 3: Elaboration of program plans and production of technical specifications
This phase was completed in June 1997. The EATCHIP Project Board reviewed the progress made on the RVSM Program and recommended that work should continue so that full implementation can be achieved on the target date of November 2001.
This phase was completed by the endorsement of the program by the ICAO European Air Navigation Planning Group (EANPG) in December 1997.
Phase 2: Advanced Planning and Preparation
In this phase the emphasis of the work program will move from the theory and initial design of the total system to the practical application and introduction of the system requirements.
The objectives of this phase are:
· Step 1: to commence the preparation of the ATS environment for RVSM operations.
· Step 2: to prepare the aircraft for RVSM operations.
· Step 3: to prepare a monitoring environment to allow confirmation of the technical performance of aircraft.
Steps 2 and 3 above will allow Phase 3 to start. Step 1 above has to be complete before RVSM (Phase 4) can be implemented.
Phase 3: Verification of Aircraft Performance
The purpose of the Verification Phase is to confirm, in a 2000 ft vertical separation environment:
· the effectiveness of the RVSM approval process;
· the efficacy of the MASPS, by measuring the height keeping performance accuracy of the maximum possible number of aircraft which have obtained RVSM airworthiness approval;
· that the safety levels of the proposed 1000 ft RVSM system will remain at, or better than, that established by the TLS.
This phase will continue until all aspects of the work program necessary to the successful completion of the verification process, and to the introduction of RVSM, have been completed. This is expected to take approximately one year.
Phase 4: Introduction of RVSM
The introduction of RVSM does not mark the end to the Program. This phase will be used to confirm that:
· all elements of the total system are operating satisfactorily, and
· the level of "vertical" risk in the system is below that tolerated by the TLS.
This phase will support the resolution of any operational issues, which might be revealed following the implementation of 1,000 ft VSM.
Phase 4 will continue until it is possible to confirm that the long-term safety of 1,000 ft VSM can be assured without further monitoring.
Figure 3 is the presently proposed timetable for the introduction of RVSM. The ability to meet this timescale depends on all stakeholders being able to complete the tasks for which they are responsible in sufficient time.
This section provides a summary of the key elements of the future work program to implement RVSM in the airspace of the European Member States and other Participating States
To operate in the notified European RVSM Airspace, both the Operator and the aircraft will need to be RVSM approved. This approval consists of:
1. RVSM Airworthiness Approval. This is the approval granted by the State Authority to indicate that an aircraft has been modified and/or inspected in compliance with the applicable approval criteria (eg. Service Bulletin, Supplemental Type Certificate), and is therefore eligible for monitoring as part of the Verification Phase.
2. RVSM Operational Approval. This is the approval granted by the State Authority to the Operator to indicate that:
· the aircraft holds RVSM airworthiness approval;
· the operating procedures and continued air worthiness procedures (maintenance and repair procedures) are acceptable; and,
· the approval of an Operations Manual, where required.
Approval criteria for RVSM Operations will be stated in JAA Temporary Guidance Leaflet No. 6 (due to be published in spring 1998). The basic technical criteria of this leaflet will be identical to that previously published in JAA Information Leaflet No. 23, which it replaces, and will be the JAA MASPS for RVSM.
Work is in progress to define the airspace requirements for RVSM operations. These requirements can be divided into three distinct but overlapping packages:
· The definition of the continuous area of RVSM applicability.
Note: ICAO have urged non-ECAC States with an operational interface with the ECAC area, in particular those which would make the RVSM area an operationally coherent and acceptable airspace, to work closely with ECAC States to introduce RVSM within the same timescales through active participation in related RVSM activities.
· The evaluation of the impact of RVSM on the Route Network and the adaptation, as required, of the Route Network and associated Flight Level Allocation System.
· The adaptation, as required, of the airspace structure and ATC sectors.
The development of ATC Operational Procedures for the European RVSM airspace is being finalised. The main areas of work are:
· Flight Planning Procedures
· Contingency Procedures
· Transition Procedures
· Procedures for handling non-RVSM approved State aircraft
These procedures, once endorsed, will be the basis for the development of an RVSM Operations Manual and ATC Training Syllabi to support RVSM.
Two items have been assessed as having significant safety implications:
· To permit operations by non-RVSM approved State aircraft, ATC will be obliged to apply two distinct vertical separation minima within RVSM airspace.
· ATC will need to ensure that non-RVSM approved aircraft, other than State aircraft, are not cleared into the RVSM airspace.
An accurate, timely and unambiguous display of information to the controller will be necessary to ensure the safe handling of this mix of aircraft in the RVSM airspace. The safe application of RVSM will require procedures for handling non-RVSM approved State aircraft. Operation of these procedures requires the provision of specialised ATC system support tools which:
· ensure that ATC can readily identify the non-RVSM approved State aircraft and can apply 2000 ft vertical separation from other aircraft; and
· prevent increased controller workload created by the handling of non-RVSM approved State aircraft.
Dependent upon the nature of the sector, the means of meeting these requirements could include the modification of the controller’s display. This requirement could be one of the critical tasks of the program.
A prerequisite for the implementation of RVSM is the monitoring of the overall system performance to ensure that the system safety targets are:
· achieved - during the Verification phase; and
· maintained - once full implementation has been introduced.
The monitoring process is based upon the application of the principles of the traditional Reich Collision Risk Model which employs data inputs on airspace and aircraft parameters in order to model operations in the particular airspace. The most important of these parameters, and the most difficult and costly to acquire, is an accurate measurement of the height keeping performance of the aircraft population.
Currently there are two accepted methods of obtaining the necessary data.
· Height Monitoring Unit (HMU). This is a fixed ground based system which employs a network of a Master and 4 Slave Stations to receive aircraft SSR Mode A/C signals to establish the three dimensional position of the aircraft. The geometric height of the aircraft is measured to an accuracy of 50 ft (1 Standard Deviation (SD)). This is compared, in near real time, with meteorological input data on the geometric height of the assigned Flight (Pressure) Level to obtain a measurement of the Total Vertical Error (TVE) of the target aircraft. The aircraft SSR Mode C data is also recorded to determine the extent of any Assigned Altitude Deviation (AAD) and for subsequent aircraft identification, when the SSR Mode S response is not available.
· GPS Monitoring Unit (GMU). A GMU is a portable "box" (contained in a carry case approximately 45 x 40 x 30 cm3) which contains a GPS receiver and a device for storing the GPS three dimensional position data, and two separate GPS receiver antenna's which need to be attached to aircraft windows using suction pads. The GMU is positioned on board the candidate aircraft and, being battery powered, functions independently of the aircraft systems. Following the flight, the recorded GPS data are sent back to a central site where, using differential post processing, aircraft geometric height is determined.
It is intended that the European Monitoring System should be a hybrid system of HMUs and GMUs, which makes optimum use of the advantages offered, by each system. Thus the strategic characteristics of the HMU - providing a predictable rate of collection of high quality data with relatively high installation and low maintenance/ongoing operating costs - can be blended with the tactical flexibility of the GMU which permits the targeting of specific aircraft at a low initial purchase price, and relatively high operating costs in both manpower and logistics.
It is planned that there should be four European HMUs (three new facilities plus the Strumble HMU, which was sited for the monitoring of the NAT traffic). The new HMUs have been positioned so as to obtain the maximum number of measurements of aircraft operating on their normal routes, as shown in figure 5. The primary means of monitoring the aircraft of those operators whose routes do not pass near to an HMU, will be a GMU. In some cases it may be necessary to request an Operator to make a minor deviation from the normal route in order to overfly an HMU. Routing an aircraft over an HMU during a non-revenue flight (eg. maintenance) is another alternative.
All data from the HMUs and GMUs will be collected and processed at a designated Monitoring Cell. The anticipated functions of the Cell will include:
· maintaining a data base of aircraft approvals and measured height keeping performance;
· analysis of height keeping performance data to:
1. initiate appropriate follow up action with the Operator of any aircraft having a large height keeping error (eg. more than 300 ft); and
2. attempt to establish the cause of any large deviations.
· execution of such measures as necessary to confirm that action has been taken to correct the cause of the deviation;
· assessment and evaluation of the risk of collision (in the vertical plane) in the RVSM airspace;
· provision of periodic reports on the safety of the system to the designated authority.
· To meet the proposed timetable, States should take such action as necessary to require that all non-State aircraft, which will operate in the European RVSM area, obtain the appropriate RVSM airworthiness approval by mid 2000 and be approved for RVSM operations by the third quarter of 2001.
· Following the publication of the JAA TGL No. 6, State Airworthiness Authorities should make available the necessary resources and documentation to publicise and facilitate the process whereby Operators can obtain airworthiness and operational approval for RVSM operations.
· To complete the many tasks listed earlier, it is essential that the aviation authorities of all ECAC Member States and other Participating States are fully involved in, and commit a high level of support to:
1. the consultative and decision making processes;
2. the planning and provision of the ATC and monitoring infrastructure required to support RVSM operations, specifically within their area of responsibility and generally throughout the European area; of particular importance is the provision of the necessary ATC support tools and facilities to allow RVSM to be introduced in November 2001;
3. the siting, provision and operation of the monitoring facilities by those states hosting the HMUs.
Airlines who intend to operate their aircraft in the future European RVSM airspace should:
· take such action as necessary to obtain appropriate RVSM approvals from the appropriate State Authority before aircraft performance verification commences. This is essential to the successful completion of the Verification Phase and to the timely implementation of RVSM;
· co-operate, to the maximum extent possible, in ensuring that their aircraft are routed over an HMU, or are measured by a GMU, during the Verification Phase;
· co-ordinate with Manufacturers to prepare, and make available, RVSM airworthiness approval packages.
Flight crews will need to have an awareness of the criteria for operating in RVSM airspace and be trained accordingly. The items should be standardised and incorporated into training programs and operating practices and procedures. Certain items may already be adequately standardised in existing procedures. New technology may also remove the need for certain actions required of the flight crew. If this is so, then the intent of this manual can be considered to be met.
Note: This document is written for Airlines who uses RVSM airspace, and as such is designed to present all required actions.
Reduced Vertical Separation Minimum in the EUR RVSM Airspace will permit the application of a 1000 ft vertical separation minimum between suitably equipped aircraft in the level band FL290-FL410 (inclusive) on 24/01/02.
The purpose of RVSM is to increase airspace capacity and provide airspace users with more flight levels and thus optimised flight profiles.
EURO RVSM AREA RVSM CRUISING FLIGHT LEVELS
* Non RVSM levels
Only RVSM approved aircraft will be permitted to operate within the EUR RVSM
Airspace. The approval is issued to aircraft operators by the responsible authority once an operator has achieved the following:
· each aircraft type has received airworthiness approval demonstrating compliance with the RVSM Minimum Aircraft System Performance Specification (MASPS),
· the State's approval of both the operations manual and the maintenance procedures specific to RVSM operations.
State aircraft are exempted from having to meet the RVSM MASPS. As a consequence, State aircraft can be accommodated in the EUR RVSM airspace provided that ATC maintains a minimum vertical separation of 2000 ft between such aircraft and all other IFR aircraft. In Field 18 of the ICAO FPL, State aircraft shall then request special handling by filling “ STS/NONRVSM” .
Comprehensive means of monitoring the height-keeping performance of aircraft in the EUR RVSM Airspace has been developed utilising two types of monitoring equipment:
Height Monitoring Units (HMUs) - fixed ground based height-monitoring facilities at Linz, Nattenheim & Geneva which monitor passing aircraft normally without action from aircraft operators;
GPS Monitoring Units (GMUs) - portable monitoring units carried on board aircraft to supplement HMUs & monitor aircraft which are not normally flying over HMUs
RVSM compliant aircraft are required to participate in the monitoring program which will commence in Spring 2000. In some cases, aircraft may request a re-routing so that they may be height monitored.
A number of FIR/UIRs in the EUR RVSM Airspace have been designated to handle the transition of aircraft from an RVSM to a non-RVSM environment and vice-versa. Within this “EUR RVSM Transition Airspace”, special procedures will allow ATC to transition both RVSM and non-RVSM Civil and State aircraft. Flight crews may expect to change from Conventional Flight Levels to RVSM Flight Levels and vice- versa. ATC will continue to provide a 2,000 feet VSM between a non-RVSM approved aircraft and any other aircraft.
The minimum equipment list (MEL) fulfilling the MASPS consists of :
1. Two independent altitude measurement systems each equipped with:
· cross-coupled static/source system with ice protection if located in areas subject to ice accretion,
· display of the computed pressure altitude to the flight crew,
· digital encoding of the displayed altitude
· signals referenced to a pilot selected altitude for automatic altitude control and alerting,
· Static source error correction.
2. One SSR transponder with an altitude reporting system in use for altitude keeping.
3. An altitude alerting system.
4. An automatic altitude control system.
1. the pilot shall notify ATC of any contingency (equipmentfailure, weather hazards such as severe turbulence etc…) which affect the ability to maintain the cleared level or the RVSM requirements (eg. MEL).
2. ATC may take appropriate tactical actions to ensure that safe separation is maintained, including reversion to a 2000ft separation minimum
3. when notified by ATC of an assigned altitude deviation of more than 300 ft (90 m), the pilot shall take action to return to the cleared level as quickly as possible.
4. If unable to notify ATC, the pilot shall follow established contingency procedures and obtain ATC clearance ASAP.
5. Examples of equipment failures which should be notified to ATC are:
· failure of all automatic altitude-control systems aboard the aircraft;
· loss of redundancy of altimetry systems;
· loss of thrust on an engine necessitating descent; or
· any other equipment failure affecting the ability to maintain cleared flight level;
The pilot should notify ATC when encountering greater than moderate turbulence. If unable to notify ATC and obtain an ATC clearance prior to deviating from the cleared flight level, the pilot should follow any established contingency procedures and obtain ATC clearance as soon as possible.
TCAS Version 6.04A is designed for a non-RVSM environment. ACAS II (TCAS Version 7.0) has improved compatibility with RVSM. The Mandatory Carriage and Operation of ACAS II for aircraft above 15000 kgs and more than 30 passengers started on 1 January 2000 with a transition period ending in March 2001.
Flight crews shall verify:
· the condition of the equipment required for RVSM operations and that maintenance actions have been taken to correct defects,
· the condition of static sources,
· the altimetry accuracy by setting the QNH or the QFE. The reading should then agree with the altitude of the apron or the zero height indication within a 75ft (23m) tolerance.
The following actions should be accomplished during the pre-flight procedure:
· review technical logs and forms to determine the condition of equipment required for flight in the RVSM airspace. Ensure that maintenance action has been taken to correct defects to required equipment;
· during the external inspection of aircraft, particular attention should be paid to the condition of static sources and the condition of the fuselage skin near each static source and any other component that affects altimetry system accuracy. This check may be accomplished by a qualified and authorised person other than the pilot (e.g. a ground engineer);
· before takeoff, the aircraft altimeters should be set to the QNH of the airfield and should display a known altitude, within the limits specified in the aircraft operating manuals. The two primary altimeters should also agree within limits specified by the aircraft operating manual. An alternative procedure using QFE may also be used. Any required functioning checks of altitude indicating systems should be performed.
Note. The maximum value for these checks should not exceed 23m (75ft).
· Before take-off, equipment required for flight in RVSM airspace should be operative, and any indications of malfunction should be resolved.
The flight crew shall pay particular attention to conditions that may affect operation in RVSM airspace:
· verifying that the aircraft is RVSM approved, ie compliant with the MEL
· analysing the reported and forecast weather that may affect RVSM requirements (turbulence, icing …),
· reviewing the manufacturer's and the operator's restrictions concerning RVSM operations.
· ICAO FPL : the letter W shall be inserted in Field 10 if RVSM approved
· RPL : the letter W shall be inserted in Item EQPT/ if RVSM approved, regardless of the requested FL.
The following equipment should be operating normally at entry into RVSM airspace:
· Two primary altitude measurement systems.
· One automatic altitude-control system.
· One altitude-alerting device.
Note: Dual equipment requirements for altitude-control systems will be established by regional agreement after an evaluation of criteria such as mean time between failures, length of flight segments and availability of direct pilot-controller communications and radar surveillance.
· Operating Transponder. An operating transponder may not be required for entry into all designated RVSM airspace. The operator should determine the requirement for an operational transponder in each RVSM area where operations are intended. The operator should also determine the transponder requirements for transition areas next to RVSM airspace.
Note: Should any of the required equipment fail prior to the aircraft entering RVSM airspace, the pilot should request a new clearance to avoid entering this airspace;
· all the required equipment shall be monitored to ensure satisfactory operation before and within RVSM airspace.
· when changing levels, the aircraft should not overshoot or undershoot the cleared flight level by more than 150 ft (45 m).
· the automatic altitude control system shall be engaged during level cruise by reference to one of the two altimeters. If fitted, the altitude capture feature shall be used whenever possible for the level off
· cross checks of the primary altimeters shall be made at intervals of approximately one hour. These primary altimeters shall agree within 200’(60m).
The following practices should be incorporated into flight crew training and procedures:
· Flight crews will need to comply with any aircraft operating restrictions, if required for the specific aircraft group, e.g. limits on indicated Mach number, given in the RVSM airworthiness approval.
· Emphasis should be placed on promptly setting the sub-scale on all primary and standby altimeters to 1013.2 (hPa) /29.92 in.Hg when passing the transition altitude, and rechecking for proper altimeter setting when reaching the initial cleared flight level;
· In level cruise it is essential that the aircraft is flown at the cleared flight level. This requires that particular care is taken to ensure that ATC clearances are fully understood and followed. The aircraft should not intentionally depart from cleared flight level without a positive clearance from ATC unless the crew are conducting contingency or emergency manoeuvres;
· When changing levels, the aircraft should not be allowed to overshoot or undershoot the cleared flight level by more than 45 m (150 ft);
Note: It is recommended that the level off be accomplished using the altitude capture feature of the automatic altitude-control system, if installed.
· An automatic altitude-control system should be operative and engaged during level cruise, except when circumstances such as the need to re-trim the aircraft or turbulence require disengagement. In any event, adherence to cruise altitude should be done by reference to one of the two primary altimeters. Following loss of the automatic height keeping function, any consequential restrictions will need to be observed.
· Ensure that the altitude-alerting system is operative;
· At intervals of approximately one hour, cross-checks between the primary altimeters should be made. A minimum of two will need to agree within ±60 m (±200 ft). Failure to meet this condition will require that the altimetry system be reported as defective and notified to ATC;
· The usual scan of flight deck instruments should suffice for altimeter cross-checking on most flights.
· Before entering RVSM airspace, the initial altimeter cross check of primary and standby altimeters should be recorded
Note: Some systems may make use of automatic altimeter comparators.
· In normal operations, the altimetry system being used to control the aircraft should be selected for the input to the altitude reporting transponder transmitting information to ATC.
· If the pilot is advised in real time that the aircraft has been identified by a height-monitoring system as exhibiting a TVE greater than ±90 m (±300 ft) and/or an ASE greater than ±75 m (±245 ft) then the pilot should follow established regional procedures to protect the safe operation of the aircraft. This assumes that the monitoring system will identify the TVE or ASE within the set limits for accuracy.
· If the pilot is notified by ATC of an assigned altitude deviation which exceeds ±90 m (±300 ft) then the pilot should take action to return to cleared flight level as quickly as possible.
· In making technical log entries against malfunctions in height keeping systems, the pilot should provide sufficient detail to enable maintenance to effectively troubleshoot and repair the system. The pilot should detail the actual defect and the crew action taken to try to isolate and rectify the fault.
The following information should be recorded when appropriate:
· Primary and standby altimeter readings.
· Altitude selector setting.
· Subscale setting on altimeter.
· Autopilot used to control the aeroplane and any differences when an alternative autopilot system was selected.
· Differences in altimeter readings, if alternate static ports selected.
· Use of air data computer selector for fault diagnosis procedure.
· The transponder selected to provide altitude information to ATC and any difference noted when an alternative transponder was selected.