Originally Posted by
Shaggy Sheep Driver
On Concorde the undercarriage is operated by the 'green' hydraulic system. The 'Green' system is driven by pumps on engines 1 & 2. Shutting down No.2 when No.1 had failed meant they could not raise the gear, greatly adding to the drag.
The gear wouldn't retract due to an undetermined fault with the left gear.....either damage to wiring around the left gear or damage to the gear door, the investigation couldn't establish exactly what.
But they established the Green hydraulic system was functional when the gear lever was selected up and although it probably lost pressure at some later point in the flight, it couldn't be determined exactly when.
Green hydraulics or not, the gear was going nowhere.