Modern-day Helicopters often include some form of AutoPilot technology, the most common of them being made by Garmin. This system allows the helicopter to handle flight paths without much input from the pilot, including course changes and directional ‘bearing’ guidance, where the helicopter follows a plotted ‘line’ on the autopilot screen. But how do these work, and are they safe?
The basis of these autopilots is a gyroscope, typically a 6-axis one. This takes a measurement of the aircraft’s potion in relation to the earth on six axis’, and feeds this data into a computer. It also takes note of the aircraft’s speed, elevation, engine power, and (in many cases) data from any on-board radar systems or Collision-Avoidance Radar. Once this information is fed into the computer, it create a profile of the aircraft, which is updated several thousand times per second.
When the pilot enters in the destination that he or she would like to go to, the aircraft calculates the changes that will be necessary to ‘autopilot’ itself to the preferred route from the difference between the preferred destination and the current aircraft profile. As of this writing, the pilot must successfully take off and reach a preset altiditude before the auto-pilot can be engaged; no current auto-pilot system can handle the complexities of takeoffs/landings for rotary wing aircraft as of now.
As the aircraft flies, changes are required to be made to its speed, heading, altitude, etcetera. The autopilot system interfaces with the aircraft’s ‘fly-by wire” controls, sending digital signals to the proper servos and actuators to mimic input from the pilot and therefore steer the aircraft. OF course, the pilot must be sitting in the pilots seat and have his or her hands available at all times; most auto-pilot systems require a degree of human input (which could be as simple as pushing a button to let the computer know the pilot is alive and paying attention) at periodic intervals.
If no input is receive, more advanced autopilot systems will begin a controlled descent, cross-referencing terrain maps to find an empty area. The most advanced autopilots will safely land the helicopter and idle the engines without any input, and some can even notify air traffic control with a pre-recorded message of an emergency.
Although AutoPilots are not so common as to be in almost every aircraft built today, even less-expensive models, such as the Robinson R-44 and R-66 offer autopilots these days. The vast majority of turbine powered aircraft also offer the system, from manufacturers such as Garmin and Uniden. An AutoPilot is a nice feature to have, but there is no substitute for proper training and an experience pilot behind the controls.