RVSM

[freddyfokker]

Hi tech question:

There is disagreement on the requirements of rate of descent and rate of climb in RVSM airspace.

There are two interpretations of the rule and I would be grateful if someone could give the correct answer.

1. Any climb or descent within RVSM airspace , from climbing into or descending out of , or changing level should be limited to 1000 fpm

2. climbing into or out of RVSM airspace is free rate of climb / descent but changing level within RVSM is limited to 1000 fpm.

I have read our company paperwork and the Racal extracts and it seems you could argue that both are correct..


Help please

[freddyfokker]

Someone must know, any North sea sector ATC'rs out there?

[karrank]

As you can see I am not from those parts.... I have read a bit about you procedures though, (we are introducing RVSM here shortly).

As I understand it there is no rule, it is just a technique for you aeroplane people to absorb. If you do the last 1000' of your level change at 1000 fpm or less you will not set off a vertical domino effect of TCAS RA in your crowded skies.

We have to really try to get a TCAS to beep here, so have not even suggested the technique.

Apparantly won't even be neccessary with later versions of TCAS more friendly to RVSM.

[10W]

Why not check out the official documentation, available online ??

UK AIC 80/00 (Yellow 24)

It's in Paragraph 3.2

When approaching the first cleared level and/or when changing flight level in RVSM airspace, aim to keep the vertical speed within 500 to 1000 fpm, do not exceed 1500fpm and ensure that the aeroplane neither undershoots nor overshoots the cleared flight level by more than 150 feet, manually overriding if necessary.

[freddyfokker]

10w

Thank you for your reply,

The real area of concern is regarding descents, climbing into RVSM airspace, we are unlikely to exceed the ROC of 1000 fpm , and when changing level a small adjustment is all that is required.

If I am flying in RVSM airspace say FL 340 and cleared to descend say to FL90 what rate of descent can I use and what would you expect.

The aircraft FMS obviously knows nothing about RVSM and will plan a descent based on the best profile, often around 2-3000 fpm.

If we need to descend at 1000 fpm we will have to ignore the FMS and descend earlier, also our flightplans will need ammending for the slight increase in fuel burn.

At the moment it seems we are all using FMS procedures and existing descent profiles is this correct?

[ayrprox]

freddy

I'm not sure about other people, but your rate of descent would not be restricted by us, but if you were descending towards traffic 1000ft below your cleared level, then approaching at higher rates may cause TCAS problems. (and I stand ready to be corrected on that coz i'm not a pilot).
Other than that I can think of no reason to restrict your rate of descent
hope that helps

[10W]

freddyfocker

Well my interpretation would be as follows:

Cleared to climb into RVSM airspace, e.g FL90 to FL320. Any rate of climb you wish till approaching FL320, then not exceeding 1500fpm.

Cleared to climb from one RVSM level to another, e.g. FL320 to FL360. Rate of climb not to exceed 1500fpm.

Cleared to descend into RVSM airspace, e.g FL430 to FL320. Any rate of descent you wish till approaching FL320, then not exceeding 1500fpm.

Cleared to descend from one RVSM level to another, e.g. FL360 to FL320. Rate of descent not to exceed 1500fpm.

Cleared to descend out of RVSM airspace, e.g FL320 to FL90. Any rate of descent you wish.


That's what I would expect pilots to comply with. Hope this helps.

[Not Long Now]

Just as an aside, why do pilots keep telling me they're non RVSM compliant when they've only filed FL180?
Or is RVSM airspace too heavy with all the extra traffic and is now sinking?