Garmin Introduces Smart Rudder Bias, Autopilot-Assisted Twin-Engine Safety Feature

Here's why it's needed. Because their engines are set so far apart, when one engine of a conventional twin-engine plane fails, the plane will yaw strongly toward the inoperative engine, for reasons that are easy to grasp just by imaging how the operative engine would want to go forward and, hence, create more lift, than the inoperative engine. The powerful yaw if not immediately corrected will result in a roll into the dead engine, a roll that almost always results in fatalities. The antidote, if you can't just land straight ahead, that is, is to feather the propeller of the inoperative engine, thereby cutting that side's drag considerably, apply strong rudder to the live-engine side, like more rudder than single-engine only pilots can imagine might be needed, clean up the plane and keep the speed at best rate of climb for an engine loss. These are just general procedures. Each twin-engine plane has specific memory-item checklists for the loss of one engine.

Garmin's new feature is part of its Electronic Stability and Protection (ESP) suite of envelope protection features---"envelope protection" is a term that Garmin tends to not use. Other ESP features include overbank and underspeed/overspeed protection, essentially features that operate full time in the background of select Garmin autopilots to have the pilot's back. So far, the feature is certified for the several Piper PA-31 Navajo models, as well as for the Beechcraft Baron B-58 and B-58A. Other certs are coming, Garmin says.

The function works like this: When the reaches minimum controllable airspeed, Smart Rudder Bias is automatically armed. If the Garmin engine monitoring system detects an engine out condition (which the system sees as an engine power differential, specific to that model of aircraft), Smart Rudder Bias goes into action, helping the pilot apply enough force to counteract the yawing. It also protects the airplane from excessive bank, which in this case will be far less of a bank angle than during, say, cruising flight.

For aircraft already outfitted with the required hardware, there's no cost for the upgrade. Some planes might need additional equipment, especially as many are not outfitted with a  rudder servo, which is necessary to make this magic work.