The invention relates to a method for calculating a flight path avoiding a collision with the ground when an aircraft dives towards the ground. The method includes receiving signals including information of a dive angle of the aircraft in relation to the imaginary ground plane, and a present roll angle of the aircraft, and calculating a flight path that avoids collision with the ground on the basis of the information. The calculation includes calculating a need for rolling the aircraft based on the present roll angle, and calculating a need for changing the direction of the velocity vector of the aircraft so that the change has a component in an upward direction in relation to the reference frame of the aircraft. The calculation of the need for rolling the aircraft is also based on the dive angle so that the calculated flight path turns sideways when the dive angle surpasses a specified dive angle and when the present roll angle is larger than zero degrees, and so that the flight path continues in a forward direction when the dive angle is below the specified dive angle. The invention also relates to a ground collision calculating unit, a computer program, and a computer readable medium.