The pilot of the twin-engine airplane reported that, during the takeoff roll on the 3,500-ft-long runway, the airspeed indicator did not indicate an airspeed, so he rejected the takeoff. He added that he attempted to brake, but "full braking [was] not initially possible due to lift." Subsequently, the airplane overran the runway onto a downhill grassy area and struck a fence. During postaccident examination of the airplane, the pilot found that the pitot tube cover had not been removed before the flight. According to the manufacturer, the typical takeoff roll is about 1,336 ft, and the approximate landing roll is 1,440 ft. If the pilot had rejected the takeoff sooner, he likely could have stopped the airplane on the runway. The airplane sustained substantial damage to both wings. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. The pilot added that his preflight memory list was: fuel, oil, tires, props, and surfaces and that he will now add "chocks, cowl plugs, pitot tube covers."