simfly,
Is there problems when using spoilers during turbulence (ie in descent) due to the aircraft experienceing that loud buffet?
There's sure problems if you encounter a large overspeed in turbulence and
DON'T use the spoilers, and whatever other means are available (like completely closing the thrust levers) to avoid the overspeed. Fairly recently I was sitting in 160 knots Tailwind which became 80 knots in a matter of seconds, fully closed thrust levers AND fully deployed spoilers even then did not prevent a Mmo exceedance by M0.026
G-ANDY,
how long does it take to get down to turbulence speed from cruise speed, and how much do you need to throttle back?
Too long (although Econ cruise these days is not too far above Turbulence Penetration Speed), in a severe encounter. Quite fast enough in Moderate turbulence when comfort is the primary consideration.
Does the aircraft / computer do this itself, or is this something the crew sort out?
The Auto Thrust responds to crew inputs, the aircraft "computer" is blisfully unaware of turbulence. It has limited authority in cruise, quite sufficient in moderate turbulence, but crew intervention definately needed in severe encounters like that described at the beginning of this post.
A300Man-2005,
who stipulates how close one aircraft should get to the next one, before deciding that it's time to hit the brakes and stop?
The rules do, as indicated by
Capt Claret, but a lot of common sense is still called for beyond these statuory limits. If I'm in an F50, behind a B747 on an up-sloping Taxiway, I know he'll apply a lot more breakaway thrust than normal and stay a respectable distance behind. Even if relative size doesn't matter, in freezing, slushy, snowy conditions I don't want the dude in front blowing all that hazardous ice forming stuff all over my shiny new US$5000 de-ice just 10 minutes prior to the end of the Hold Over Time.
Best wishes,
Old Smokey