Frequently Asked Questions (FAQs)

What is AlphaTrainer?
The AlphaTrainer instructional device is a useful tool that explains angle of attack and how to properly approach stalls and spins. More importantly, AlphaTrainer illustrates how to avoid these inherently dangerous situations. AlphaTrainer stresses the importance of understanding that what the pilot perceives is not always perfectly correlated to Angle of Attack. To emphasize this misperception, a “Pilot’s Perceived Attitude” (formerly called the “Pilot’s Viewing Attitude”) illustrates the differences. The user can graphically see the angle of attack, the pitch attitude, the horizon, the elevator position, the instantaneous flight path, and the pilot’s line of sight, which creates the Pilot’s Perceived Attitude.

Who uses AlphaTrainer?
From newcomers to Airline Transport Pilots, all pilots can learn from the AlphaTrainer instructional device. It comes with a CD containing free reprints of FAA training manuals that are written for new pilots, and they can easily convert these words into visual demonstrations with AlphaTrainer. And airline transport pilots can use the AlphaTrainer to do the same thing using the advanced they have learned. Most import, however, is that flight instructors can use AlphaTrainer to teach AOA, and also use it to test the student’s AOA comprehension.

What does the Pilot’s Perceived Attitude have to do with angle of attack?
The pilot’s perceived attitude illustrates that what pilots see is not always perfectly correlated to Angle of Attack. For example: Assume a pilot is following several slower aircraft in the traffic pattern. To maintain adequate spacing he reduces power and extends a notch of flaps. In the turn to base leg, he’s looking through the top portion of the windshield. As turn performance decays due to the increased drag of the wing at a high angle of attack, the pilot sees that he is overshooting the turn. Typically, the pilot increases bank and pulls the yoke back to tighten the turn. The aircraft loses more speed and begins to sink. The situation is bad and getting worse, partly because the pilot is not accurately anticipating WHAT THE AIRPLANE’S WING IS ACTUALLY DOING. Stall speed is increasing but airspeed is not. It sounds difficult to believe, but this is a typical precursor to the common stall/spin accidents in the base-to-final turn. Developers of angle of attack indicators frequently demonstrate their units using this scenario, because the airspeed is typically in a safe range throughout the base-to-final turn, while the airplane is rapidly approaching a stall.

Why can’t pilots make a distinction between attitude and angle of attack?
Usually, familiarity with actual pilot’s view tricks the mind’s eye for changes in angle of attack. In most light airplanes, the airplane will pivot—on its center of gravity—up to15 degrees to compensate for changes in speed, atmosphere, and weight caused by “G” loading. This pivot is AOA. AlphaTrainer is instrumental in developing a concept where the Pilot’s Perceived Attitude is more aligned with the Instantaneous Flight Path than with the attitude of the airplane. For example, visualize that you’re in level flight and want to reduce your airspeed from cruise speed to minimum controllable speed. During cruise speed, let’s say an AOA of 4 degrees, the attitude of the airplane and the Pilot’s Perceived Attitude are essentially level. As the airplane slows to generate an AOA of 12 degrees, the attitude of the airplane will adjust up 8 more degrees. To maintain altitude, the airplane must be held in this nose-up attitude, therefore changing the attitude of the pilot’s body. However, the pilot’s eyes continually adjust to follow the horizon reference. Perhaps a simpler way is to visualize rocking in a rocking chair while continuing to stare at a picture mounted on a wall. As the body moves upward, the eyes will tend to move downward to remain fixed on the picture.

Would an angle of attack indicator help in recovering from the stall scenarios you have discussed?
Absolutely. We must understand that stall recovery requires the maximum lifting capacity of the stalled wing, especially when at a low altitude. This is the key purpose of angle of attack indicators; they register how much the wing is capable of lifting without stalling.

Why are most light airplanes not equipped with an angle of attack indicator?
Simple. The FAA does not require them. Nevertheless, I believe the fundamental problem with non-use of AOA indicators is the Law of Primacy; wherein something learned first leaves an almost unshakable impression. Most of us aviators have learned stalls by using some mark on an airspeed indicator. Then after we accepted that, we were told that a stall could occur at any airspeed, in any attitude, and with any power setting. How much safer would our pilots be today if all of us would have started with an AOA indicator and learned the phase: From Red to Green is our Dream?
Jim Frantz of Proprietary Software Systems, Inc. expands.
Contact Jim at (952) 474-4154 or www.angle-of-attack.com.
“Early aircraft were equipped with simple AOA indicators, including the Wright brothers’ aircraft. However, when the tractor driven (propeller in front) aircraft became popular, it turned into a problem of where to put the AOA sensor. The sensor needed to clear the prop wash and still be far enough ahead of the wing to avoid configuration errors. This problem has largely been solved by new technology that eliminates the need for vane based sensors.”

Do the airlines and the smaller jets have angle of attack indicators?
Yes, most high performance airplanes have some form of angle of attack indicator, because stall recognition is difficult. The U.S. Navy uses angle of attack almost exclusively for landing on carriers. A friend—and former Naval instructor—frequently states, “I would rather lose my airspeed indicator any day over my angle of attack indicator.”

Are there inexpensive angle of attack indicators for small airplanes?
Yes. We at AlphaTrainer recognize the importance of such devices. Please research different medium, including the Internet, and encourage the manufactures to advertise the benefits of these devices.

Why no FAQs for AlphaTrainer 3D?
See our AT3D Q&A Page, or download the AlphaTrainer 3D Pro User's Guide.

Hosted by LunarPages.