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From the Mid Atlantic Radio Kontrol Society, Snow Hill, Maryland

Learning to 3-D and 3-D Well; Part 3 of 5: High Alpha Knife-Edge Flight

by Jeremy Chin

In the previous articles, you got the right equipment (both virtual and real) and you learned how to fly a Harrier. Then you expanded your 3-D horizons by learning to fly an Inverted Harrier. You are well on your way to building a solid base of fundamental 3-D skill.

Next in line is another fundamental skill that can be built upon later. It is time to learn to do a High Alpha Knife Edge.

If you followed earlier suggestions to build your basic aerobatic skill set, you learned to fly a Knife Edge during that effort. If not, then go back and learn to fly it. Make sure you can fly both left tip down and right tip down, and both orientations with the top and the belly of the airplane toward yourself. This basic aerobatic skill can also be developed quickly using the simulator.

If and when you are comfortable flying regular Knife Edge flight, you are ready for the next step in your 3-D education: High Alpha Knife Edge. This name is really just the common name for flying Knife Edge at a high angle of attack.

To learn this skill, start by flying a regular Knife Edge down the field repeatedly. As you fly, gradually increase the rudder deflection, while balancing that against changes in throttle. Some airplanes require more throttle, some less. All have a point of equilibrium that you must find on your own.

This skill can be learned at any lower altitude, but I’ve found that having the lower wingtip at around eye level is the most effective. This altitude gives enough time to roll the airplane back to level in the event of a problem, but is not too high to allow good vision of the airplane.

You may find that the airplane you are flying will require a higher angle of attack in high-angle-of-attack Knife Edge than it did for Harrier flight. This is because the fuselage typically has less area than the wings do, and thus requires a higher angle of attack, more power, or both, to maintain a flat heading. You may also find that you need some aileron correction or elevator correction to keep the airplane on the same heading while in High Alpha Knife Edge. Fly the airplane in this case rather than relying on a mix. I’ve found that rarely are mixes effective in maintaining High Alpha Knife Edge when compared to regular Knife Edge.

  continued on page 6