Move to reduce vertical separation will result in fuel savings and fewer delays, outweighing implementation costs.

Reduced vertical separation minima (RVSM) will take effect in US domestic airspace as planned on 20 January 2005, under the final rule published by the Federal Aviation Administration. Operators of out-of-production aircraft, mainly older business jets, had hoped for a reprieve, arguing there is insufficient time to modify their aircraft.

The FAA says domestic RVSM, which will reduce vertical separation between aircraft from 2,000ft (610m) to 1,000ft for all aircraft flying between 29,000ft and 41,000ft, will result in fuel savings and delay reductions worth around $5.3 billion by 2016, outweighing the $870 million cost, which includes $530 million to fit aircraft with more-accurate altimeters and autopilots.

Engineering firm CSSI says pilot and controller training will cost $8.5 million and monitoring altitude-keeping performance $4.2 million, while aircraft downtime costs for Part 135 charter operators will be over $74 million and fuel penalties incurred by non-RVSM aircraft forced to operate below 29,000ft will be almost $104 million by 2016. RVSM in European airspace has resulted in fuel savings and emission reductions of 1-2%, says CSSI.

Manufacturers are concerned that operators of older business jets are leaving it too late to upgrade their aircraft for RVSM. By the end of this year, with less than 13 months to go, Cessna will have upgraded only around 300 of the 1,500 Citations potentially affected by the rule. Cessna says operators have been holding off scheduling upgrades awaiting the FAA's delayed release of the final rule, hoping for a reprieve. Now the rule is final, and the deadline confirmed, the number of aircraft still to be modified could exceed the capability of avionics suppliers and modification centres, Cessna warns.

Source: Flight International