Andrew Doyle/DUBROVNIK
Airline pleas to Europe's air traffic control authorities for more space in the sky to fly their aircraft could be answered on 23 April.
This is the date that Eurocontrol's Provisional Council is due to deliver its judgement on detailed proposals for the introduction of reduced vertical separation minima (RVSM) in Europe's upper airspace.
If all goes to plan, six new flight levels between 29,000ft (8,850m) and 41,000ft will become available to commercial traffic on 24 January 2002, namely 30,000ft, 32,000ft, 34,000ft, 36,000ft, 38,000ft and 40,000ft.
None of those involved in this highly ambitious project, however, is underestimating the scale of the task that lies ahead before RVSM can be successfully implemented.
The restructuring will directly affect the companies that operate, and the pilots that fly the more than 8,000 civil aircraft regularly using Europe's upper level airspace, along with air traffic controllers in 38 countries.
Many of these aircraft will have to be modified to improve the accuracy of their altimetry, allowing vertical separations to be safely reduced to 1,000ft, from the current 2,000ft.
Any aircraft not approved formally for RVSM operations by the appropriate civil aviation authority will be banned from flying at or between 29,000ft and 41,000ft except for those operated by the military, customs or police (designated "state" aircraft).
At stake are cost savings that the International Air Transport Association (IATA) estimates will be in the order of over 2 billion euros ($2.3 billion) by 2014. It believes most of this - 1.926 billion euros - will result from reduced delays. The remainder, IATA says, will be accounted for by fuel savings derived from better flight profiles and improved access to upper flight levels.
This differs substantially from the benefits gained from RVSM introduction on the north Atlantic in March 1997, where most savings came from the use of more efficient routings.
Eurocontrol sees the introduction of RVSM as the "most cost effective" way of finding badly needed extra capacity as it tackles the problem of severe congestion in Europe's upper flight levels. The organisation's studies into the introduction of RVSM came up with a benefit-to-cost ratio of over 11, based at the time on its mid-range forecast of a 3.1% increase in traffic a year between 2000 and 2015.
Significant obstacles must be overcome, however, if RVSM is to be successfully implemented in Europe, Eurocontrol officials told delegates at the RVSM workshop held in Dubrovnik, Croatia, on 20-22 January.
Eurocontrol, the European air navigation organisation, with 27 member states, has been tasked by the European Civil Aviation Conference (ECAC) states to manage the implementation of RVSM.
The complexity of the air route structures over Europe, coupled with the wide variety of aircraft types in use, high traffic density and large proportion of climbing and descending aircraft, means that the task will be significantly more difficult than that for the north Atlantic, where most aircraft fly in predictable "waves".
Not least of these obstacles is how to handle the transfer of traffic into and out of RVSM airspace on Europe's eastern borders. The western side should be "seamless" with RVSM already having been introduced on the north Atlantic.
"The main task has to be carried out at the [eastern] peripheries where the transitions are taking place," says Erik Sermijn of Eurocontrol's Airspace and Navigation Division.
An approved aircraft entering European RVSM airspace from the east must be moved to an RVSM flight level by the first air traffic control centre (ACC) by which it is handled. Non-state aircraft without RVSM approval must fly below 29,000ft or above 41,000ft.
Conversely, aircraft must leave the RVSM airspace at a non-RVSM flight level, ready to be handed over to the neighbouring ACC.
This means, for example, that the predominantly west-bound flight levels of 31,000ft, 35,000ft and 39,000ft could become eastbound ones within RVSM airspace, requiring aircraft at those heights to climb or descend by 1,000ft when entering or leaving the RVSM zone.
Sermijn says possible solutions for the transition areas include controllers making "tactical" altitude adjustments using radar, applicationof a flight-level allocation scheme (FLAS),"freezing" 31,000ft, 35,000ft and 39,000ft within a specified area or creating dual, laterally separated routes at the RVSM boundaries.
In general, Eurocontrol is advocating the easing of so-called "hard" FLAS systems, where specific flight levels are used for traffic heading in a certain direction, because of the introduction of the extra RVSM flight levels. This, it believes, will allow the airspace to be used more flexibly, providing the maximum potential for increased capacity.
Eurocontrol RVSM programme manager Joseph Sultana says: "We hope that there is no FLAS at all because there are six extra flightlevels. We only come to the rigid implementation of FLAS where traffic builds and builds."
CHANGES TO PROCEDURES
Changes to flight planning procedures will also have to be made. Current proposals call for pilots to file a specific request for their desired flight level upon entering or leaving RVSM airspace. In addition, pre-defined identifiers will be used in the flight plan to indicate whether an aircraft is RVSM approved, non-RVSM approved or exempted under the so-called state aircraft rules.
Another major issue is how to control the flow of state aircraft, which will be allowed to use RVSM airspace but will still require minimum vertical separations of 2,000ft.
The proposed air traffic management procedures for RVSM airspace are still in their draft form but have been approved by Eurocontrol. They have been formulated taking into account real-time computer simulations performed using Dutch, Hungarian and Romanian airspace, as well as the "core area", encompassing France, Germany and Switzerland.
Sermijn says the simulations indicated that a significant increase in capacity could be achieved without the need for re-sectorisation, and that aircraft would be able to operate closer to their optimum flight levels. The presence of non-RVSM-approved state aircraft, however, increased controller workload considerably.
Sultana says the proposed introduction of RVSM initially caused concern about its effect on military aircraft operations.
"Simulation studies showed, however, that with the appropriate co-ordination procedures and tools, military operations were possible in RVSM airspace and the 'crossing' of upper air routes could still be achieved," he adds.
To tackle the "considerable" disruption to RVSM likely to be caused by the presence of military aircraft, Eurocontrol has made "-strong recommendations to the military to try to get those aircraft to be RVSM compliant", says Sultana. "The first real job we have set out to do is to make sure we talk to the military organisations," he says.
Progress has been made in this respect, with the US Air Force having indicated it plans to make all of its transport aircraft in Europe compliant by 2002. Most tactical aircraft are unlikely ever to comply, but often require only to cross commercial air lanes.
Discretion for granting military aircraft access to RVSM airspace rests with individual air traffic control centres, representing a setback for operators such as the USAF that had been pressing for guaranteed access to flight levels between 29,000ft and 41,000ft.
Eurocontrol is taking responsibility for briefing national training managers from each of the countries involved in the RVSM changes. The managers will then be responsible for overseeing training of air traffic controllers. It hopes to complete the briefings for trainers by early 2000.
It is not, however, getting directly involved in flightcrew training. "It is the responsibility of the airlines to train their flightcrews to operate within RVSM airspace," says Sultana. The Joint Aviation Authorities (JAA) has already published guidance material for aircraft operators on RVSM requirements, known as TGL 06.
"TGL 06 is a very clear document and we hope it will be distributed soon and that everyone will follow that," says Sultana.
He admits that the question of training for general aviation and corporate pilots is "-more complicated. The requirement is still there, but how a state is going to make sure that a general aviation pilot has the training is not going to be easy to administer".
Programme managers are aiming to ensure that airlines receive the aircraft certification criteria by November, to ensure that enough are capable of participating in the monitoring programme, due to get under way in March 2000.
"Otherwise, we will not have enough data from the monitoring programme," says Sultana.
The approval and monitoring of aircraft for RVSM operations is critical. If not enough aircraft are compliant or insufficient data from the monitoring programme are available when the pre-implementation safety assessment is made in July 2001, the introduction of RVSM will have to be delayed.
Operators wishing to use RVSM airspace will be required to gain approval from the civil aviation authority in the country they are based or from the nation in which their aircraft are registered. The legal requirements, covering airworthiness, altimetry accuracy and main- tenance and flightcrew procedures, are laid down by the International Civil Aviation Organisation (ICAO) and the individual civil aviation authorities.
Aircraft not compliant at the time of delivery will have to be modified according to manufacturer service bulletins (SBs) or supplementary type certificates held by design organisations.
RVSM implementation on the north Atlantic was not achieved on time because of delays in the aircraft approvals process, the availability of SBs and in processing RVSM approvals for airlines. Eurocontrol is keen to learn the lessons from this experience.
To ensure the safe implementation of RVSM, Eurocontrol will collect data on height-keeping performance from early 2000 to March 2001, ahead of the final safety assessment. This means that significant numbers of aircraft will have to be approved by early next year to enable a statistically significant data sample to be gathered. Unlike implementation of RVSM on the north Atlantic, however, each operator will not be required to have their aircraft monitored before gaining approval.
Eurocontrol will install three height monitoring units, one in Austria, one on the French/Swiss border and the third on the border between Luxembourg and Germany. These will be capable of measuring the altitude of overflying aircraft by monitoring secondary surveillance radar returns. The geographical position of the units should ensure that, within the first 12 months, nearly 70% of all aircraft operating within European airspace will overfly them.
The rest of the data will be collected using global positioning system monitoring units mounted on individual aircraft. These operate independently of the aircraft's systems and measure altitude using signals beamed from navigation satellites. "This will give us 12 months of monitoring data and we will add to that what is coming in from the north Atlantic," says Sultana. All of the data collected by March 2001 will be analysed and included in the pre-implementation safety report.
MASTERPLAN
The final draft of the European RVSM "master plan" was sent to the national programme managers in the 38 countries involved on 19 January. The programme management board is expected to issue its approval on 4 February, (and in early March) Eurocontrol's air traffic management/communications, navigation and surveillance consultation group will consider the plan. The go-ahead is expected to be given by Eurocontrol's Provisional Council, made up of the director generals of the national civil aviation authorities of the 27 Eurocontrol member states, on 23 April.
Sultana says the management team is effectively saying to the council: "This is how we will do it, these are the timescales - we need a firm commitment."
Under the proposed timetable a pre-implementation safety assessment will be made in July 2001, ahead of a final go/delay decision in September that year. IATA says it supports Eurocontrol's approach to RVSM implementation but is pressing for it to be achieved earlier, at least in the core areas where the benefits of extra capacity would be most acute.
"We are in favour of earlier implementation everywhere if possible," says Razvan Bucuroiu, IATA assistant director infrastructure - Europe. "There could be states that can do it earlier and we will encourage them and work with them to do it." He adds: "If it will not be possible for full ECAC implementation by March 2001, then we are in favour of a phased implementation."
Bucuroiu says the concept has full support of the airlines, given the worsening level of flight delays in Europe, and that the target of 90% of flight operations being performed by RVSM-approved aircraft can be "easily achieved".
Eurocontrol's Sultana says: "RVSM will bring benefits that are urgently needed but we also have to make sure we can deliver what we say we will. We have learned the lessons from other projects. Everybody must follow a strict programme management discipline if a programme with so many players is to be implemented on time."
Referring to the delayed introduction of basic area navigation in Europe after a large number of airlines requested exemptions, he says: "That was because we didn't have the full picture. With RVSM we cannot have the same situation."
Source: Flight International
