What should a driver confirm about the landing gear during the combination-vehicle walk-around inspection?

AAMVA CDL Manual, Section 6.5.1, p. 6-13

Landing gear that is bent, only partially raised, or missing its secured crank handle can fail to support the trailer during a future uncoupling, or can snag on something in the road while the rig is moving, which is why it gets its own dedicated check beyond the standard seven-step inspection.