^ sounds like a possibly good idea. Won't really help with gliding but it's always something towards more realistic behavior.
Or maybe like this:
check the ASF vertical angle - it you have noise pointed out than at 0 thrust your speed will slowly go down (very slowly I mean. If you shut thurst down at 200km/h your speed should be zero after 20-30 seconds). If you point nose 90 degree down at your speed will go towards XXXkm/h, the assumed glide-speed (speed change varies depending on how down the nose is, at -5 deg the change is very slow). If you point nose 90 degree up, than your speed goes down to zero quickly.
If you press and hold X your air breaks open and you decelerate more quickly, also this way you can reach forward speed 0 in air (additional thrusters make you stop...whatever. Though still you fall down vertically).
This way you'll nearly always have some speed in air, making you always fly. There's no stall effect, but it's far better than having everything float after X being pressed.
