Timely detection of subnormal acceleration and appropriate pilot reaction either to continue the takeoff or to reject it and stop on the remaining runway is vital to the safe operation of today's transport category airplanes. But ironically, pilots have no direct, accurate means to assess actual airplane acceleration during takeoff. Despite a history of infrequent but sometimes catastrophic accidents in which takeoff performance was a factor, little progress has been made to remedy this situation. Occasionally used techniques and two developmental systems to monitor acceleration are described. A novel and promising approach which uses the onboard inertial navigation system also is described and is advocated as a means to enhance pilot judgment and decision-making during the takeoff roll. This scheme offers potential for significant improvement of air transport safety with a minimum of development effort and equipment cost.