On 17/01/2019 13:36, NY wrote:
"Chris B" wrote in message
...
Due to the demand for high level flight routes (initially over the
Atlantic) there was a major exercise to reduce this separation to
1000ft (Reduced Vertical Separation RVSM) - but this has very specific
requirements on the proven accuracy of the aircraft altitude (and
other) systems). If you cant meet the requirements you cant fly in
RVSM airspace.

I am reminded of the comments that David Gunson made in his legendary
after-dinner speech "What Goes Up... Might Come Down". I'm doing this
from memory, so I may not be word perfect, but it was something like...

"The chances of two aircraft being at the same place, at the same
height, at the same time is so mathematically remote as to be not worth
bothering about. Air-traffic controllers force them down narrow
corridors to increase the chances of a collision, thereby justifying
their jobs in keeping them apart."

Actually all joking apart, the ATC system was evolved in the early days
of international air travel. Today with all airliners having GPS and
Satcom there is work in hand to enable them to fly wherever they like,
rather than just down recognised air corridors, using technology to let
other aircraft know where they are and "see and avoid" - much like
private pilots work in the bottom 5000ft of airspace using the Mk1 Eyeball.

It will still all come back to ATC and procedures in the area of
airports I suspect.

--
Chris B (News)