automatic flight control system knows where it is

#AUTOMATIC FLIGHT CONTROL SYSTEM KNOWS WHERE IT IS PLUS#

However, this is an area that can catch a new autothrottle manager by surprise. If you have 250 knots selected, the autopilot will pitch the aircraft to capture and maintain 250 and the autothrottle will reduce to climb power. As can be seen from looking at the sidebar, selecting FLC will transition the AP to flying the selected airspeed and the AT will transition to climb power. Normally the pilot will select VS or FLC for the initial climb. If another FD/AP mode is not selected within the time limit for takeoff power, the AT will retard the levers to climb power. The majority of these require the pilot to arm the system for takeoff and then push the levers forward, where the AT takes over and completes the forward movement to takeoff power. The operation of the autothrottle is straightforward and intuitive, but there are a few areas to be aware of. The side bar below shows all the AFCS vertical modes and what is being controlled by the FD and what is controlled by the AT. If the FD/AP is not controlling airspeed, then the AT will control to the selected airspeed. The AT has logic that knows if the AP is controlling airspeed then the AT will control the power. Either the FD/AP or the AT can control airspeed, but not both simultaneously. The AT monitors the pitch mode of the FD/AP to determine if it should be in SPD or PWR. The AT is also less complex because all the mode determination is already done in the FD/AP. Having said that, there are some ATs which have a hold mode (HLD) which is basically disengaged. The first is speed (SPD) and the second is power (PWR). There are a lot of modes for a FD/AP, but there are only two modes for an autothrottle. However, to get the most out of the automation, you need to know its limitations and quirks.

#AUTOMATIC FLIGHT CONTROL SYSTEM KNOWS WHERE IT IS PLUS#

Everything else in the AT operation is determined from the FD/AP selection plus the engines and configuration of the aircraft. The only control to contend with is simply engage/disengage and selection of the desired airspeed.

It’s automatic without having another controller to manage. Because the autothrottle integrates seamlessly with the flight director, there is no contention on what system is controlling airspeed. Why is it such a hit? Primarily because it is simple and straightforward to operate, even more so than the flight director/autopilot (FD/AP). An autothrottle truly completes the picture. Many pilots have thought that the autothrottle was a gimmick until they have had a flight with the additional automation. The relaxation comes from having an extra set of hands that do what you command. There is no other piece of avionics that helps provide a relaxed flight like a fully integrated AFCS. Today’s pilots operating a fully integrated automatic flight control system with autothrottles are truly system managers. Since autohrottles are new to many pilots, this article will attempt to remove some of the mystery.Ĭockpit automation has radically reduced the physical workload for pilots and consequently improved the safety of flight.

Soon, all pilots will have the opportunity to fly fully integrated systems with autohrottles. The trend toward more automation will continue to migrate downward into piston aircraft. However, today’s AFCS with autothrottle (AT) are becoming common on single engine turboprops. Only a few years ago, a fully integrated automatic flight control system (AFCS) with an autothrottle was the sole domain of the air transport aircraft and heavy iron business jets.

Automatic flight control system knows where it is