I have been going through my RC stuff and here is another gem. It is tested fine and never crashed.
Co-Pilot 2-Channel, 2 Axis Flight Stabilization System
Part Number: CPD4
The original Co Pilot (PN CPD4) is a patented, 2 channel, 2 axis Flight Stabilization System (FSU) that senses the difference in infrared signature (temperature) between the earth and the carbon dioxide in the atmosphere to provide 100% real time, day or night stabilization about two axes (pitch and roll) on virtually any model. The system maintains level flight for aircraft and heli requiring only 2 radio channels to control pitch and roll. This limitation means CPD4 does not handle CCPM helicopters or aircraft configurations that include differential ailerons or flapperons. If your model requires 3 or 4 radio channels to control pitch and roll, click here to learn about the new Co Pilot II FSU.
How does Co Pilot work?
The Co Pilot CPD4 is composed of two main components; the sensor module and the computer module. The sensor module must be mounted to the outside of the aircraft and plugs in to the computer module. The computer module is installed between any R/C receiver and the servos controlling the aircraft's pitch and roll flight surfaces. The sensor module contains 4 independent IR thermopile sensors. The sensors are mounted 90 degrees apart and look out in all directions toward the horizon. The viewing angle of each sensor would be represented by a 90 degree cone. Each sensor is capable of seeing several square miles of area taking a wide angle view of the "composite" or "average" surrounding temperature profile. Objects with comparably small temperature profile such as a grove of trees or a house blend in to the overall IR picture. The overall effect of the IR readings tend to give the impression that Co Pilot is picking up on the horizon. So we might say Co Pilot can level the aircraft to within 1 degree of the horizon, but the reality is that sensor range is probably less than 1 mile. Therefore, it does not really "see" the horizon. It sees the average temperature profile all around and inside of 1 mile to determine level attitude relative to the sensor module installation. By comparing the relative heat signature measured by each cone, the CPD4 computer utilizes the raw analog signals from the sensor module to alter the radio receiver's control pulses to the servos. In essence, the CPD4 is always attempting to maintain the aircraft in a level attitude by balancing out the heat signature all around the aircraft. The pilot is therefore "over-riding" the Co Pilot's natural tendency when he flies.