Originally Posted by
clubord
However if ATC asks for a speed reduction or increase that will change the descent rate, you'll feel that and/or notice the speed brakes on the wings and feel the "rumble" when they're deployed.
Hope that helps!
That reminds me of something. Is this a bogus memory, or would it have been part of the normal procedure? On a United DC-8 flight years ago, I recall the use of inboard thrust reversers during flight, presumably as speed brakes? This was with the new engines of the 1980s vintage.