Originally Posted by
Rod1
“You can always fly IFR in VMC in anything, quite legally”
Absolutely not allowed, if you do this overtly you will get reported as you are in breach of your permit to fly which states daytime VFR only, flying under IFR is not allowed on a permit!
Rod1
Which is a silly bit of wording, since you can be IFR and VFR simultaneously in VMC. It, of-course, means, stay VFR.
Originally Posted by IO540
If a GPS delivers true altitude, then it's good for CAS separation where CAS is defined as altitude.
Obviously I agree re the other reasons for barometric altimetry... I was just being provocative
And wrong. If CAS is defined by altitude, it's defined by pressure altitude on the appropriate QNH, not by geopotential altitude. If it's not defined by that, it's on flight level, which is still pressure altitude, but on 1013.25hPa.
G