Abstract: The presently disclosed subject matter includes a collision warning and avoidance system and method for detecting a collision risk between an interrogating aircraft and at least one interrogated aircraft. Signals received from the at least one interrogated aircraft or by the at least one interrogated aircraft and at least one other interrogating aircraft are used for determining various situation awareness data which is used for determining whether the interrogating aircraft is in a risk of collision. If indeed a collision risk exists a collision warning is generated, the collision warning including data indicative of at least an estimated location of the at least one interrogated aircraft.