I asked my son many questions about the T-6, including flight controls. I asked about a loss of hydraulics, and he said there was a knob to pull that requires 80 ft-lbs of force that aligns an accumulator that will extend the landing gear. Once the gear is down, that's it. You can't retract it; it must be reset on the ground. His text today, "Had a great flight today. Did some aerobatics, loops, and precautionary emergency landing for training purposes."