A drill support consisting of a cylinder of about 2-in (5.1-cm) bore in which the piston is actuated by compressed air controlled by a twist-grip control valve. This valve is also used to release the air pressure to allow the piston to be lowered. The control valve also regulates the feeding pressure on the drill. The length of feed of the Holman Airleg is 39 in (99 cm), overall length 57 in (145 cm), and weight 25 lb (11.4 kg). A vent hole near the top of the cylinder allows the air to escape when the piston travels past it, so as to warn the operator that the limit of feed has been reached. The leg is then readjusted for drilling to be resumed. The leg gives good support to the drill at all heights within reasonable limits, and one person can comfortably handle a drill when mounted in this way.