My 2 cents:
GD is not a safe speed but a minimum drag speed. But in my opinion there is no valid reason to go below GD. Slats are mainly produceing lift with a minimum amount of drag. If you can get a grip on AB drag graph you'll see that flying 10kt below GD produces about the same amount of drag as flying the same speed with slats out.
But there is another component to that. Although GD is not a safe speed, flying at or above protects you COMFORTABLY in any case. Try to fly at GD with the speed breakes out and do a 30 deg bank turn and you'll see that VLS is is about 1 or 2 kts below GD. So no major action needed by the engines. That is what really scares the pax and not the pitch build up by extending slats.
Conclusion:
It is perfectly safe to fly below GD but there is no need to and is therefor not recommended by the manufacturer.
Do not compare an AB with what you have learned on a conventional aircraft. GD is not minimum clean speed. But there is still reason not to fly below, although it's not a safety issue.
You safe more fuel with a decent desent planning than with flying below GD and THIS is a real issue within EK crews.
Last edited by what_goes_up; 30th Jun 2006 at 16:40.