This pneumatically operated high-pressure hydraulic pump supplies the telescopic lifting cylinder of a mobile aircraft lifting device that lifts commercial aircraft, e.g. when changing wheels. The pump is installed in the tank. The rapid feed of the telescopic cylinder takes place via pneumatic pressurization of the oil tank. When the cylinder comes into contact with the load, the pump automatically delivers up to a maximum hydraulic pressure of 700 bar. Internal stroke reversal makes additional valves superfluous.