Very nicely stated Cosmo, this is what I mean when I refer to "waivers and exemptions" Not quite as cut and dried as you originally posted eh?

"If they weren't RVSM equipped then ATC would deny them access to RVSM airspace. Pretty simple really."

Previous threads implied that the aircraft may have flown in MNPS or RVSM airspace without the required equipment i.e. rules not complied with. In these instances ATC WILL refuse access. A planned, pre-arranged request is somewhat different to what was being suggested in the previous posts.

ATR at FL290? Must've been -500, 42-300 needs ISA-10 to get to FL240, our current ceiling due to being non-RVSM. In the groundschool I've been taught that FL250 limit is due to pressurization. At that FL differential will reach 6.35 PSI (limitation) and cabin alt 6740 ft. If you go higher, outflow valves will maintain that differential and cabin will start climbing with the a/c. On ATRs that I fly excessive cabin altitude warning goes off at 10 000 ft cabin altitude. Silencing the bell and just moving along wouldn't be most appropriate course of action.

What about buffet margins - which are sometimes the limiting factor when operating ac at high level.

Cheers,
mcdhu

Cosmos.
It is not always possible to have a ferry aircraft fully equipped. In fact the very reason for ferry can be to take the aircraft to have it equipped.
Have ferried on many instances with no RVSM, no TCAS, No 8.33, no INU etc and have usually found ATC very accomodating.
There is nothing magic about it you just ask and if they can do they will
;)
If not you just have to go round, under or over:)

GotTheTshirt - That's pretty much exactly what I've said!:confused: :D