The A2-A Lower turret hanger.
The hanger is of the fixed type for the A2-A, fixed internally to the ceiling of the fuselage by a bolted swivel. Compared to the A13-A type that is lowered in and out of the aircraft, mainly found on B-24s. The B-24 uses a front nose wheel in conjunction with the main landing gear has to rear (tail) tire and therefore the tail clearance to the tarmac is not so great. This would not be a good thing for the lower turret and gunner to be extended at the time. I guess you might say, never leave your ball hanging out before touchdown.