Separation standards action prompted by A380 tests
All aircraft types will soon face a programme to review the current in-trail and approach separation standards based on the energy in the wakes they produce.
The US Federal Aviation Administration, Eurocontrol, Europe's Joint Aviation Authorities and Airbus met last week in Brussels "to agree a formal structure of the working arrangements" for a reclassification programme.
The case for a general review of wake-related aircraft separation distances has been strengthened by lessons learned during the recent tests carried out on the Airbus A380, according to the FAA's wake turbulence programme manager Steve Lang, but he says that reclassification would have been "inevitable" anyway. "It was going to occur," he says.
The head of Eurocontrol's airport and environment division Paul Wilson, who referred to the joint Eurocontrol/JAA/FAA A380 tests as "trailblazing", says he is optimistic that a reclassification programme framework could be drawn up by the end of the year.
Lang says the A380 wake turbulence analysis programme was significant in that it was the first new large aircraft for which there was a programme to determine wake-related separation standards before the type's certification.
This was partly, he says, because lidar wake-vortex detection technology, which determines turbulence by measuring laser light reflected by moving air particles, had become sufficiently mature to enable meaningful tests to be carried out.
He says another factor is that the US National Transportation Safety Board had already proposed that all new large aircraft types should be classified for their wake characteristics during their flight-test programmes.
Lang explains: "Analysis will be done on all new large aircraft. The air traffic control community needs a single, globally harmonised separation standard." Wilson says: "States have maintained safe separations by making their own amendments."
Determining the cost of a reclassification programme is important, says Wilson, as is the issue of where the funding will come from. This, he says, can be worked out when the outline plans are in place and the International Civil Aviation Organisation is brought into the process.
Wilson forecasts that reclassification "may not be all that expensive" to achieve and Lang says "it might be possible to take a simple cut at reclassification" with further refinements in the future.
Why should we reclassify?In some states, according to Eurocontrol's airports and environment department head Paul Wilson, aircraft are divided into just four wake-separation classes according to weight bands: heavy, heavy medium, medium light, and light. The problem, Wilson says, is that some aircraft produce much more turbulent wakes than others in the same weight category, and national classifications vary widely. There are now 15 variations to the basic categories within Europe, says Wilson, adding that this "has a huge impact on safety". Pilots, he says, do not know what approach and departure separations they should expect in different countries, so there is an urgent need for a scientifically based, internationally approved wake vortex classification system. |
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Source: Flight International
