The cooperative Landing system for coarse environment can be installed in all kinds of helicopters and helps the pilot for landing his helicopter in conditions that he does not have enough visibility. For this purpose, three important parameters for this system are diplaying the alignment of the helicoter to the ground, distance of helicopter from ground and detection of obstacles and objects below the helicopter. Therfore, initial studies were done first and it was decided to use the ultrasonic method and relavant sensors. Then the laboratory prototype was built and tested in vitro and the bugs of this sample were fixed. Finally, the final sample was evaluated in field test and after several tests and necessary modifications, it was approved by the employer. The results show that this system is a good supplement to other measurement equipments of helicopter such as altimeter radar and helps the pilot to land safely.