Julian Moxon/PARIS
BUSINESS-JET OPERATORS are becoming increasingly concerned about the costs of upgrading older aircraft to prepare them for the new reduced vertical-separation minima (RVSM) rules, recommended by the International Civil Aviation Organisation (ICAO) and due for introduction on the North Atlantic in early 1997.
Owners of older types of aircraft equipped with analogue navigation systems face upgrade costs of up to $300,000 per aircraft to meet the Minimum Aircraft System Performance Specification (MASPS) criteria necessary for operation in RVSM airspace. Even those with modern aircraft will have to spend a minimum of $10,000 per aircraft to upgrade to MASPS standard. Operators who fail to re-equip their aircraft face exclusion from the flight levels at which they were designed to be operated and could, as a result, be subject to big rises in operating costs.
Implementation of the RVSM in the North Atlantic (NAT) region is due in January 1997, although this may slip to March, or the following January. Its introduction will double the number of flight levels available above 29,000ft (8,850m) by reducing the required altitude separation from 2,000ft to 1,000ft. Aircraft being flown in RVSM airspace must be equipped with digital air-data computers (DADCs) and associated systems enabling the precise height-keeping (within 50ft of the allocated altitude) necessary for RVSM operations.
Business jets account for only 3% of NAT traffic, yet, will have to meet the same criteria as airliners. Most recent aircraft will be able to be upgraded with few modifications - Gulfstream IVs, for example, need only to have the area around the static port "cleaned up", to ensure that altimeters perform according to the tight RVSM height-keeping specifications. Older aircraft (such as the Cessna Citation III), not equipped with a DADC and associated systems, however will need to have $150,000-300,000 spent on them to upgrade. "All that money gets us is the continued use of airspace that currently we can use for nothing," said one delegate at the recent European Business Aircraft Association (EBAA) meeting in Brussels.
Most business-aircraft manufacturers are already preparing RVSM data packages for their aircraft, although few will be ready in time for NAT implementation of the rules. Introduction in European airspace is now set for 2001, however, which the EBAA regards as a more important deadline than that for NAT. There is also the possibility of a more flexible approach from the authorities for non-approved users.
FURTHER STUDY
Jacques Vanier, of ICAO's European office, says that there are proposals for non-approved aircraft to be allowed to climb through RVSM airspace, using the original horizontal-separation criteria. He adds that ICAO is now carrying out a study to assess the impact of the RVSM on the business-aircraft community, which will be completed in mid-May. A further study on procedures, which would allow business-aircraft operators wanting to fly above RVSM airspace to get there without being penalised is due for release in September.
Business-aircraft operators have already succeeded in making their concerns known, and have brought about a change in strategy which has resulted in a more gradual approach being taken by ICAO than the "big-bang" introduction originally envisaged. This entails declaring contiguous flight levels within the Minimum Navigation Performance Specifications airspace within which the RVSM is implemented.
"The advantage is that the penalties for non-approved operators would be reduced," says Vanier. The number of flight levels used would be determined by the number of approved aircraft operating in the system daily, and an assessment of the "critical mass" of daily operations would be made "...to ensure that airspace was not unnecessarily sterilised".
Vanier says that perhaps three flight levels "...which would have to be very carefully defined" (he suggests FL330, FL340 and FL350) could be made over to RVSM operations on the understanding that only approved aircraft would be using them. Non-approved aircraft would have to be operated above or below, using 2,000ft separation. "Although this does impose a penalty on non-approved aircraft," admits Vanier, "it is not as Draconian an exclusion from RVSM airspace." As more and more aircraft are approved, the RVSM altitude band would be extended. There would be a "defined end" for this phased approach, he adds.
The availability of data packages from the manufacturers will clearly be a major constraint for some operators flying less common types. Vanier says that this is a "significant" area of concern, not least because the relevant civil-aviation authorities will have to approve any modifications. Vanier points out that a problem facing the business-aircraft community is that it will be virtually impossible to obtain group approvals, as with airline aircraft, because business aircraft have customer-specified avionics.
Pressure from the US National Business Aircraft Association has enabled the ICAO-recognised International Business Aircraft Council to become an observer to its NAT Systems Planning Group.
The hope is that this will ensure that the business-aircraft community is properly represented in the RVSM debate. As one EBAA member put it: "If we don't lobby the rule makers, how can we expect them to hear us?"
Source: Flight International
