Abstract: An improved landing gear assembly made up of a pair of supports having extensible legs, each support having a generally rectangular air lift bladder encased in a box enclosure, which forces a leg downwardly when the bag is inflated, there being an internal compression spring urging the leg upwardly against the air bladder, the leg and spring being located within a generally tubular housing. Each support includes a safety latch and lock mechanism for fixing the leg with respect to the leg housing. The safety latch and lock includes an array of notches formed on the lower end of the extensible leg, a pivoting latch for engaging a selected notch, a torsion spring urging the latch into engagement with a notch, a rotatable rod linked to the pivoting latch of each support, and a handle for rotating the rod.