The hawker has something called 'Lift Dump' associated with the air brakes. It lands with flaps 45 and when brought to lift dump, the flaps continue to 75 degrees while the airbrakes increase from I believe 59 degrees to 74 on the bottom, and somewhere like 30 to 59 on the top. I'd have to look into the book for the airbrake increase though. All in all, when you use lift dump, it slows the thing down. I fly both the A with and without TRs, and the XP with TRs and I'll tell ya, lift dump really slows you down!