We can't specify any particular decelaration rate as we can't be familiar with all different a/c performance in this respect. We rely on literature and experience to know general acceptable speeds for bands off a/c. We wouldn't expect air brakes on, gear down and arms out the window just a sensible reduction. If an extreme deceleration is required, where wider vectors are not the best option, this will be specified...if this is not possible plan B will be formulated....quickly.
