A Comparison of Short Selling and Put Option Activity

The present invention provides ground proximity warning system and method for aircraft, particularly rotary wing aircraft such as helicopters. The warning system generally includes an air ground detection device disposed on the aircraft to confirm whether the aircraft is on the ground or in the air. A controller is coupled to the air ground detection device and configured to move between a ground state when the aircraft is on the ground and an airborne state when the aircraft is in the air. The controller may be used for a variety of applications within the aircraft, such as disabling a ground proximity warning device when the aircraft is on the ground and enabling the warning device when the aircraft is in the air. In addition, the air ground controller may be used to signal the beginning and the end of a flight for the aircraft's flight history fault memory.