When an aircraft experiences an engine failure during takeoff, it must be able to either reject or continue the takeoff without exceeding the longitudinal or lateral dimensions of the usable runway. This paper focuses on the lateral deviation. During certification, the minimum control speed ground is determined in certification tests; at this speed, the allowable maximum lateral deviation is 30 ft. These tests are done with a free castering nose wheel and other requirements such as not using ailerons. These are all V _mcg increasing factors. On the other hand, the aircraft manufacturer chooses the most favorable conditions, new tires, a dry runway, and no crosswind. It is unclear if the free castering nose wheel is a stringent-enough requirement to compensate for reduced runway friction, and the effect of crosswind is not considered in the certification tests. Furthermore, the rejected takeoff condition is not certified against a lateral excursion limit. Therefore, in this paper, a model is developed to determine the lateral deviation in a continued as well as a rejected takeoff, including the effect of pilot reaction time, runway surface condition, and crosswind. For the present evaluation, a Boeing 737-300 model was used.

Vmcg, or ground minimum control speed, is established by aircraft manufacturers during the aircraft certification process. Vmcg is used as a limiting speed for V1 (decision speed) when performing takeoff performance calculations. Performance calculations on contaminated and slippery runways will result in a V1 speed equal to Vmcg-limited V1 for a wide range of takeoff weights when using aircraft manufacturer procedures in a flight crew operationsmanual or computer calculations based on theV1−min policy. In this paper, itwill be shown thatVmcg will not be a safe speed to continue a takeoff after an engine failure in strong crosswind or reduced runway surface friction conditions. A model is used to determine the effect of these environmental conditions on lateral deviation. Apart from the continued takeoff, the lateral deviation in the rejected takeoff after an engine failure was also calculated under different environmental conditions. This resulted in advice for the use of a differential braking technique to prevent a runway excursion if a runway is not dry. A method to mitigate the risk of runway excursion on contaminated and slippery runways is presented. An evaluation, conclusions, and subjects for further research are also presented.