EMMA KELLY / LONDON
The implementation of reduced vertical separation minima (RVSM) in most of Europe is like running a marathon, says Joe Sultana, RVSM programme manager at Eurocontrol, Europe's air navigation organisation, which has been leading the effort. If that is the case, the "runners" - aircraft operators, air traffic service providers, regulatory authorities and aircraft manufacturers - are well beyond the pain barrier, with the finish line finally in sight.
It has taken a monumental effort and more than four years of planning to get there - but in a matter of weeks Europe will learn whether the training and preparation have been worth it. The RVSM programme involves 41 countries in Europe and two in North Africa, around 6,000 controllers at 65 air traffic control (ATC) centres, and 2,300 operators flying around 9,000 aircraft which comprise 104 different types.
Freeing up space
On 24 January, the region's air traffic management (ATM) environment will radically change when RVSM or a 1,000ft (300m) vertical separation minimum, instead of the traditional 2,000ft, will begin to apply between flight level (FL) 290 (29,000ft) and FL410. This change will create six new flight levels and much-needed additional airspace capacity in the congested European core.
The implementation of RVSM is the biggest change in European airspace for 50 years, and it returns much of the continent to the ATM environment of the 1950s when vertical separation for aircraft flying in upper airspace was 1,000ft.
Separation standards at and above FL290 changed to 2,000ft in 1960 when it was realised that, as the arrival of jets raised the optimum cruising levels considerably, the accuracy of pressure-sensing barometric altimeters would not be sufficient above FL300. The International Civil Aviation Organisation (ICAO) adopted a standard, global FL290 change-over level in 1966. But as technology advanced, more accurate height-measuring equipment became available and global traffic levels increased, a reduced minimum became a necessity.
Rising fuel costs and demands for more efficient use of airspace prompted ICAO to start examining the feasibility of RVSM in the late 1970s. Studies followed in the 1980s in Canada, Europe, Japan and the USA, with results showing that global vertical separation reduction would be safe and bring cost benefits.
Trials
The North Atlantic became the testing ground for RVSM in 1997 when a 1,000ft separation minimum was introduced between FL330 and FL370 inclusive, with the programme extended between FL310 and FL390 inclusive a year later. RVSM would never have been contemplated for European airspace if it had not been successful in the North Atlantic region, says Sultana. It has since been implemented across the Pacific, and now regions around the world are looking to RVSM to ease their airspace capacity woes.
Although RVSM has been done before, it has never been introduced in such a complex and busy environment as European airspace. North Atlantic traffic is characterised by similar types of aircraft and uni-directional tidal flow. By comparison, Europe has a huge number of different aircraft types, high traffic-density and a large percentage of climbing and descending aircraft, as well as an intricate route structure, full of major crossing points.
RVSM is essential in Europe where, before 11 September, traffic had grown on average 7.4% a year since 1980, with the result that, today, only a third of flights in Europe are on time. The average delay is 4min, a loss equivalent to around 2,000 years of passenger time annually, says Sultana.
Until 2005, RVSM is set to be the major pan-European initiative for dealing with ever-increasing air traffic. Eurocontrol estimates that RVSM will increase air capacity in Europe by 20% and give a cost: benefit ratio of 1:14.
European RVSM is expected to yield huge cost benefits for aircraft operators, primarily from delay reductions and fuel savings, as the addition of six flight levels at the most fuel-efficient cruising altitudes means traffic flows can be more flexible. According to conservative estimates, an average of 80kg (176lb) less fuel will be used for each flight in the RVSM environment. Based on 10,000 flights a day using European airspace, this adds up to more than 290,000t a year, says Eurocontrol.
At current prices, this represents a saving on fuel of c60 million ($54 million) per annum. Total annual cost benefits are estimated at c4 billion. Although that figure is based on pre-11 September traffic levels, Sultana believes cost-savings will still be great as traffic picks up.
Ireland and the UK introduced RVSM procedures in April. Their experiences have been positive, says Eurocontrol, and the knowledge gained has been incorporated into the wider European programme.
European RVSM introduction will also have major implications elsewhere. "Many other regions of the world are waiting to see what happens in Europe before they implement RVSM in their own areas," says Sultana. The Middle East, for example, is looking to introduce it in 2003, while the USA is planning domestic RVSM implementation a year later.
"Now, more than ever, Europe is ready for RVSM. We just need to make sure the change-over works and to avoid any last minute problems," adds Sultana.
The countries involved are ready for the new procedures, he believes, with all necessary ATC upgrades completed and tested, and controller training well under way. RVSM entails many operational changes for flight planners, pilots and controllers. They have had to learn new procedures in RVSM ATC; flight planning; contingency and transition; handling aircraft not RVSM-approved; and new radio/telephony phraseology.
All affected states must be ready at the same time or European RVSM cannot go ahead. Each air navigation services provider has had to develop and implement a national plan derived from the European-wide RVSM master-plan; upgrade its ATC system support; evaluate its route network to make it compatible with RVSM operations; and train its controllers.
The transition states where the RVSM zone begins and ends, which include Finland, Morocco and Turkey, have had the most work to do, as they have had to implement specific procedures to prepare traffic for the core of Europe. These countries have introduced new route structures, in addition to equipment and training upgrades.
Training
Training across Europe has involved 6,000 air traffic controllers, according to Sultana. Eurocontrol has briefed trainers and provided five workshops and training packages, though it has been up to individual countries to model a course suitable to their own airspace requirements.
Most aircraft operators are also ready, says Sultana. To operate in RVSM airspace, aircraft must meet globally applicable aircraft height-maintenance standards contained in minimum aircraft systems performance specification (MASPS). MASPS requires at least two independent altimeters on board to be kept within a certain tolerance of each other.
While new aircraft are RVSM-compliant, those older than three years generally need modifications if they are to fly in RVSM airspace and avoid being confined to less fuel-efficient levels.
By late December, 8,500-plus aircraft had met these requirements and received full RVSM approval. Although Eurocontrol had originally hoped that around 9,500 aircraft be accepted at this stage, it is still expecting this figure to rise as 24 January approaches.
The post-11 September downturn has affected operators' RVSM plans, says Sultana, with some airlines delaying RVSM modification programmes as they determine future fleet requirements in response to the industry slump.
Aircraft RVSM approval has followed an extensive height-monitoring programme to ensure aircraft types meet stringent height-maintenance requirements. The height-monitoring process, which started in May 2000, has involved three units - at Geneva in Switzerland, Linz in Austria and Nattenheim in Germany - measuring the performance of a representative sample of aircraft flying in European RVSM airspace.
Eurocontrol has great confidence in the accuracy of the height-measuring equipment, with systems performing exactly the role they were intended to, revealing problems only in six or seven aircraft types, says Sultana. Among these types were the Embraer ERJ-135 and ERJ-145. TwentyERJ-135s/145s exhibited skin-rippling around the static ports, which affected height-maintenance accuracy. This resulted in their RVSM approval being withdrawn until a solution was implemented, says Sultana.
Problems
"If we hadn't found that the problem was isolated to those 20 airframes, all ERJ-135s/145s would have been restricted. The manufacturer and operators now know what they have to do to fix it. This was exactly why the height-monitoring programme was started - to identify such problems."
In addition, the programme identified a problem with British Aerospace/Avro 146/RJs. The manufacturer has since devised a procedure to rectify the problem, associated with the static port.
Several Russian aircraft types, including the Antonov An-124 and An-72, and the Ilyushin Il-86, also failed to meet height-keeping requirements.
The manufacturers have been approached over the problems, and Sultana expects the defects to be remedied, although he concedes that it has been more of a problem obtaining corrective information from Russian aircraft manufacturers than from their European and US counterparts.
To obtain RVSM approval, aircraft operators have also had to prove to their certification authorities that their pilots have undergone an RVSM training programme. Airlines have handled pilot training in different ways, says Sultana.
Eurocontrol produced a flight operations awareness video and distributed it worldwide to help operators. Some carriers, such as Finnair, have devised their own training packages and sold them to other airlines. The Finnish flag carrier's computer-based training product, which was initially developed to train its own 650 pilots, includes an introduction to RVSM procedures covering flight planning, rules governing aircraft prior to RVSM airspace entry, as well as within RVSM airspace, contingency concepts and post-flight procedures.
Business aircraft operators have "struggled a bit more" with RVSM compliance, says Sultana. The programme has proved expensive for them due to the modifications required - but they knew about RVSM implementation well in advance, and business aviation industry associations are supporting it, making the process easier, he says.
Eurocontrol agreed with military authorities two years ago that military aircraft would be exempt from the RVSM requirements, but the military was encouraged to make transport fleets compliant with the requirement in order not to affect airspace capacity adversely. Military aircraft have a much better compliance level than expected, says Sultana, with 60% of military flights above FL290 today flown by RVSM-approved aircraft.
Around 70 flights daily across Europe will be performed by non-RVSM-approved military types, and will be largely confined to the Mediterranean, France, Italy and Switzerland, he adds.
Communications
"Military aircraft equipage is better than expected, especially on the part of the US Air Force so we don't think the impact will be great, but we will look at it in the first few months," says Sultana. The military have agreed to curtail any major exercises from 24 January to 31 March.
One outstanding issue for RVSM implementation is a new radio communications procedure. It was due to be published before the end of last year, but has yet to be signed off by ICAO. "It won't stop us from going ahead, but it is an outstanding issue," says Sultana.
Eurocontrol is expecting some RVSM teething problems immediately after introduction, but intends to minimise these as much as possible by ensuring RVSM procedures are followed and by increasing capacity gradually. "We have to make sure that any flight planning that's not correct is rejected. Operators know what they have to do in flight planning," he adds.
In the first few weeks of RVSM operations, capacity will be reduced by 15% to 25% to ensure that controllers can manage aircraft in an RVSM environment. In particular, UK airspace capacity will be limited as the New En Route Centre in Swanwick, southern England, is due to go live on 27 January. After four to six weeks, capacity throughout Europe will return to normal levels, says Sultana.
Eurocontrol expects capacity benefits as late March, coinciding with the beginning of the summer schedule and the lead-up to the summer traffic high-points. Simulations suggest that increases of 10-15% could be achieved as early as this summer, Sultana says - much sooner than originally expected. Capacity is expected to reach its estimated target of 120% in September.
Exactly how successful RVSM has been will be determined in December with the first of two post-implementation safety assessments, the second following in December 2004.
Sultana's four-year RVSM marathon is almost over and Europe appears ready to cross the finishing line.
Source: Flight International
