Abstract: An extricating device for persons with spinal injuries including a support board positionable on the back, neck, and head of the person. The support board is conformable to the back, neck, and back of the person. The support board includes a main section and an upper section extending upwardly from the main section. The upper section is positionable under the neck and head of the person. A plurality of straps are coupled with the support board for securing the support board to the person. Each of the straps are adjustable.

Abstract: A method is disclosed for determining the heading of an aircraft which is equipped with both an inertial navigation system and a device capable of receiving navigation satellite signals and computing the aircraft's position, speed and acceleration therefrom. While the aircraft is still on the ground and before flight operations begin, an initial alignment of the inertial navigation system with an earth-fixed coordinate system is performed, and during this alignment, data corresponding to the initial attitude of an aircraft-fixed coordinate system relative to the earth-fixed coordinate system is also determined and stored. Thereafter, during flight operations, the acceleration vector of the aircraft relative to the aircraft-fixed coordinate system is measured by the inertial navigation system and then transposed into a coordinate system which has been horizontally aligned with the earth-fixed system using the initial attitude data.