A probabilistic model is described for the lateral displacement of an aircraft after the occurrence of an engine failure during take-off. With the model, a lateral boundary is calculated, for any point of time after the engine failure, such that the probability of being within the (two sided) lateral boundary meets a specified value. Various probability distributions for the three model parameters are considered. The model is elaborated for one specific set of probability distributions. The resulting lateral boundaries are compared with the present ICAO annex 6 obstacle accountability area.