crazypilot. .. .Remarkable, isn't it, just how often those who post vehement and dogmatic replies to questions end up with egg on their face!. .. .Concorde can use reverse thrust in the air.. .. .Irish Steve has it nearly right, however only the inboard engines are used in the air, never the outboards. Reverse Idle only, Subsonic only, plus a few other limitations.. .. .The descent profile is planned without the use of reverse thrust, but it is available, and used, if required.