A drive apparatus is provided to transmit force from a source of power to a driven assembly, such as a pump, in an aircraft. The drive apparatus can be operated from a disengaged condition back to an engaged condition when the aircraft is on the ground. The drive apparatus includes a first annular array of teeth which is connected with an input member and a second annular array of teeth which is connected with an output member. A plurality of disengagement levers extend outward from the output member. A retaining member is connected with outer end portions of the disengagement levers. An actuator member or yoke is movable to move the retaining member and the outer ends of the engagement levers to disengage the drive apparatus.