Buff From Australia, joined Mar 2007, 0 posts, RR: 1 Reply 2, posted (13 years 6 months 2 hours ago) and read 2610 times:
RVSM has been in place on an experimental basis on the NAT for 3 years. It has just been introduced on the Pacific OTS. After several more years of freedom from aluminum rain, RVSM will probably be introduced into mainland Europe and the USA.
Reduced Vertical Separation Minima changes those limits above FL280 mentioned by L-188 above from 2000 to 1000' separation of opposite direction traffic.
In the old days of pressure altimeters, given the fact that atmospheric pressure changes are not the same at high levels as they are closer to terra firma, and given the state of development of air data sensing systems, it was felt that an added 1,000' was necessary in the higher flight levels. Now with the development of ADC's, accuracy is easier to attain. Hence the experiment with RVSM.
And it's working. It's an exciting time to be in aviation. Changes are occuring much more frequently than in the past.
Other kinds of change though may not be so progressive (LAHSO/SIRO). Another thread!