Transmitter vs. Receiver Flight Modes

A typical flight entails several phases. After initial prep such as fueling, the first step would be to check controls, followed by a taxi to the runway, the takeoff, climb out, cruising, aerobatics, and landing. Each of these phases, or flight modes, could entail different control settings or limits such as flaps, landing gear, control throws, and different mixes.

When you are configuring an airplane in your transmitter, you might assign each of the control features to a different switch. You might have a retracts switch, a rate switch for roll, another for pitch, another for yaw. You might have one switch for flaps, and a different switch for crow. Some things might always go together, so you might need to flip several switches at the same time to reconfigure the aircraft for a different phase of the flight. Alternatively, you could combine several features onto a single switch, so that you can flip fewer switches to reconfigure it. That’s what we call the “Flight Mode Switch.”

Depending on the model, each flight mode might have different settings for retracts, throttle behavior and setting, stabilization needs, and flaps, as well as different expo and travel settings for control surfaces. By combining the always-together settings into a single switch, the pilot’s workload is decreased and safety, reliability, and performance can all be increased simultaneously.

Your Spektrum transmitter supports up to 10 Flight Modes using up to 4 different switches, depending on aircraft type. Transmitter flight modes are typically used to combine functions such as rates, expo, and mixes during aerobatic stages, and flaps and rates during takeoff and landing. The settings for each flight mode would increase throws or add drag as needed.

The receiver in the aircraft can also have up to 10 flight modes. While these can be the same as in the transmitter it is not necessary for them to be that way. For stabilization purposes, the flight control really only needs to know how to respond to changes in the aircraft’s attitude. This is done using only the gains, as the receiver has no understanding of active mixes outside of the normal wing/tail type settings. It’s very likely that a receiver will only need a few flight modes.

Receiver flight modes are commanded using the servo position of a channel, as you would see it on the Monitor screen. For AS3X/SAFE systems, this channel controls the stabilization settings used by the receiver.