In 2016 the FAA launched its “FlySafe” mission. They recognized that the loss of control problem in General Aviation is the number one cause of fatal accidents. They reached out to the pilot community and asked developers to come up with a solution to the LOC problem. The FeelFlight system emerged as the best. With haptic feedback, combined with visual and audio feedback, it most effectively conveys to pilots critical aircraft attitudes. While the system is hugely effective, there still is a primary area of concern regarding LOC … it is the insidious skidding turn.
One thing that was apparent regarding nearly all efforts by developers to design a solution was the fixation on inadvertent stall as the cause of LOC. The flight training that all students receive is to practice stalls. This is typically done in level flight. It is mixed with power on and power off but that is usually the extent of it. The assumption is that if the pilot learns to recognize imminent stall, he will avoid it and thus not enter LOC. WRONG!!! Straight and level stalls is not where pilots typically get into trouble. It is the SKIDDING TURN!!!
So what is a skidding turn. First, it typically happens turning base to final. It also happens on the “return to target” maneuver performed by aerial applicator pilots … which by the way is the number one market for FeelFlight. When turning base to final, the pilot may be waiting too long to initiate his turn. Often he kicks in extra rudder to increase his turn rate. This would be fine, but the problem is they have a tendency to keep the wings level. VIOLA!! … you now have a skidding turn! If they would bank the wings they would have a coordinated turn … which is safe. In a skidding turn the inside wing is blanked out by the fuselage. In addition, the wing has a cross flow of air over it which robs lift. To top it off, the excessive rudder typically pushes the airplane a bit into a bank, but the pilot gives opposite aileron to arrest the bank. This down aileron on the inside wing increases the the tendency of the inside wing to stall. What happens next is almost always fatal! The inside wing stalls sending the airplane into a snap roll! The outside wing is still flying and the lift from that wing flips the airplane over. The plane goes inverted and spins into the ground. Occasionally, but rarely, the pilot survives. Crash investigators ask if he heard the audible stall warning. The pilots always say they never heard it. This is because it never sounded. The angle of attack sensor that activates the stall horn is not triggered. Again, this is because of the aerodynamics of the insidious skidding turn. As a point of reference, recall observing snap rolls at air shows. Those snap rolls are initiated by excessive rudder, keeping the wings level, and pulling back on the stick until the inside wing stalls. The airplane does a 360 degree roll in a heartbeat. Essentially, the base to final fatal turn results because of an inadvertent snap roll. Important note: by contrast the slip is typically a safe maneuver.
A key feature of the FeelFlight system is the inclination output. Left and right LED lamps blink when the plane is uncoordinated. Also, haptic thrust pins on the left and right of the grip duplicate this signal. In our initial development, it was believed that this double modality of sensory output to the pilot would adequately prevent the skidding turn snap roll. And in fact it should. However, Barry Schiff who writes a safety column for AOPA magazine, pointed out to me, if there was an audible command that warned the pilot that he was entering a skidding turn, this could go a long way to prevent the LOC. He added, that with todays sensors it must be possible to sense when the plane is entering a skidding turn. The sensors do exist, but harnessing them to specifically identify a skid is easier said the done. However, after five months of intensive development, FeelFlight now very effectively senses a skidding turn. When it does, the LED lamp blinks, the thrust pin pokes … and here is the great part – a firm voice in the headphones says either “RIGHT RUDDER” or “LEFT RUDDER.” This of course is commanding the pilot to step on the appropriate rudder to get them out of the skidding turn. Armed with the knowledge that this command is specific and is going to save his life, the pilot will definitely respond and avoid the snap roll.
With this feature developed, we have been demonstrating it to pilots. Recently a pilot responded and said, “man, that is great! What other dodads are you going to add next?” I responded, there will be no more additions or modifications, the product is now perfect. It is now the ultimate and perfect system for preventing loss of control.
Occasionally we also get a response something like, “it seems like a great idea, I just wonder about all those thrust pins and LED lamps going off all the time.” Clearly, this person hasn’t really grasped what the FeelFlight system does. Basically the thrust pins, LED lamps, and audio warnings are only activated if the pilot is entering an unsafe aircraft attitude. Otherwise, it is completely transparent. A typical pilot could fly an entire flight and never hear, see or feel any of the FeelFlight warnings.
FeelFlight,Inc. has also been selling the system with the option to not include the grip. Adding the grip to the yoke is more involved than just installing the AOA sensor and the control module in the panel hole. Omitting the grip also significantly reduces the price of the system. You lose the haptic feedback but still have audio and visual. Also, the grip can be added later. Haptic feedback is clinically proven in many tests by the Army, AirForce and others that it is by far the most effective sense for getting through to the pilot.