Letting go of the stick would have saved 447. So what are you going to do after descending 5 min. If you couldn't fly the aircraft before what happens in those magic 5 min? Divine intervention? You PA for a pilot on board?
This is not rocket science. Just learn how to fly the aircraft you are on. It's that simple.

One of the joys of flying a Bus is that for the most part it flies above the weather. If you ice probes you have hit a warmer air mass. Descending will keep you in Icing conditions delaying getting airspeed indication back, and will probably descend you into the weather and turbulence. This will greatly increase the workload. If a pilot can not handle loss of airspeed in a stable cruise situation, he will be very challenged now.
In aviation it's best to keep it simple. In the cruise if you loose the airspeed indication select the power and attitude you had prior to the loss. Run the checklist. Job done. If you want to get all fancy turn the bird on, but understand that attitude is what you need to fly, and bird will determine if you need more or less thrust.

donpizmeov,

The procedure is crystal clear:

-Xcheck indications, if one confirmed reliable, use that ADR

-If all sources are affected and above FL250, keep one on

-If all sources affected and below fl250, use the BUSS

There is not a word about immediately descending to FL250 to use the BUSS

I was referring to Vilas who seems to like the descending bit.

I am not suggesting anything different. I was just thinking had 447 descended instead of doing what he did. I standby the official procedure. I have always supported manufacturer's procedures.

Lantirn
When you discover UAR will you keep AP on?

What do you mean?

Memo items, plus, there is a high probability that you will be in altn law

Edit: I think I know what you have headed for, the correct answer would be If the safety of the flight is impacted

My doubt is without AP can you continue in RVSM?

Ah, you meant after recovery.

Actually I never thought about RVSM it to be honest. Assuming that we had two correct remaining sources I would continue with AP on, yes, to be legal. Good hint.

No. Not after recovery. After discovery of UAR you disconnect AP and ATHR and fly pitch and thrust. All three ADRs are unreliable. Are you allowed to remain in RVSM?

Procedure for unreliable airspeed is to turn all automatics off. That includes the auto-pilot. RVSM is a minor consideration. Fly the aeroplane. When safe to do so communicate with ATC.
I hope you don't teach this stuff vilas.

If all ADRs are unreliable you are in a serious emergency. No you are not allowed normally, BUT, if you declare mayday you don't care about separation and RVSM, it's the controllers job.

donpizmeov
I know the procedure including AP off. There is never any doubt about fly the plane. You did what you could you still don't have reliable ADR. My question is how long would you continue in RVSM air space in this condition? Especially your aircraft being in direct law. If there are no terrain issues would you not like to descend out of RVSM and take your chances? I am not suggesting anything but asking a question.

I am not sure we are talking about the same thing. In the unreliable airspeed case above FL250, one ADR is kept on to keep you in ALTN law. I see no great rush to descend.