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Written by John Glezellis
RC Scale Aerobatics
As seen in the June 2018 issue of Model Aviation.

As an International Miniature Aerobatic Club (IMAC) competition pilot, you must overcome various challenges. Some examples include learning new sequences and how to perform each maneuver. Modelers must also become familiar with the aerobatics figures and judging criteria, no matter what type of weather (within reason) exists.

I became involved in RC Scale Aerobatics competition after being a spectator at the 1994 Tournament of Champions (TOC) in Las Vegas. Since then I have seen many pilots who are new to aerobatics competition only practice when weather conditions are favorable. You must not fear strong wind or poor weather conditions because who knows what the weather gods might bring on competition day.

Throughout the course of this column, I will discuss proper wind correction techniques for figures that need them and teach you which maneuvers do not require wind correction.

Without further delay, let’s get down to business!

Wind Correction Fundamentals

A pilot is required to perform all maneuvers to perfection. Pilots should know that the flight path, not the attitude of the aircraft, is judged. Loops and partial loops must be round, vertical lines must be perpendicular to the horizon, and horizontal lines need to be parallel to the X or Y axis.

Not all maneuvers are wind corrected—including the stall turn, tail slide, spin, and snap roll—because they involve an airplane in a stalled state. When the airplane is stalled, it will drift, and that drift amount is disregarded by the judges.

Flying With the Wind

Flying in wind is difficult, but with proper practice, a pilot can make the required corrections that result in a flawless routine in any headwind, tailwind, or crosswind.

To begin, you must become familiar with the wind and how your model behaves. Practice flying horizontal lines parallel to the runway in a headwind, tailwind, and crosswind. As a turnaround maneuver, use a stall turn at the left and right side of the aerobatic box. The stall turn is not wind corrected.

At the top of the figure, the model might not pivot 180° if it’s flown into a crosswind. With a crosswind blowing in and the aircraft traveling from left to right, a pilot needs to lean it slightly into the wind before the maneuver begins, during the pull to vertical, and on the vertical upline. If the airplane is yawed 10° out and the model pivots around the top, a pilot must establish a vertical downline where the nose of the airplane will face into the wind by 10°.

The rotation of the figure at the top is not to be wind corrected, and the airplane can drift at that time because it is in a stalled state. With the degrees noted, the model will only rotate 160° over the top of the figure.

Pay attention to the aircraft’s position and try to keep it at the same distance for each pass. When flying in a crosswind, you will notice that rudder correction is mandatory to keep the nose pointed slightly into the wind and to maintain the same distance. Otherwise, the airplane will drift significantly.


When flying in a crosswind, a pilot must yaw the aircraft into the wind at the appropriate angle to allow for a flight path parallel to the flightline.


For vertical uplines and downlines in a headwind or tailwind, a model must be pitched into the wind for a flight path that’s perpendicular to the horizon.

If you are flying in a headwind or tailwind, the aircraft will travel slower into the wind compared with downwind. Throttle management is essential to maintain a constant flight speed. Wind speeds vary and might increase at different altitudes. What works at one altitude might not work at another!

Let’s look at a few maneuvers found in the 2018 Basic sequence and what you might need to implement depending on wind conditions.

Roll

1. Upwind maneuver entry

• Higher throttle setting to maintain constant speed.

2. Downwind maneuver entry

• Less throttle might be required to maintain constant airspeed.

3. Crosswind

• Use rudder to keep model yawed into the wind to maintain proper positioning.

Stall Turn

1. Upwind maneuver entry

• Orient, in pitch, into the wind for vertical flight path.

• Airplane might drift during pivot, which is acceptable.

• More elevator might be required during the pull to exit the figure compared with the entry to maintain a proper flight path.

2. Downwind maneuver entry

• Orient, in pitch, into the wind for vertical flight path.

• Aircraft might drift during rotation, which is acceptable.

• More elevator might be required during the initial pull to vertical compared with the exit radius.

3. Crosswind

• Orient the nose into the wind to maintain the same distance before and after the pivot.

Half-Reverse Cuban 8

1. Upwind maneuver entry

• Shallow (less than 45°) entry angle allows wind to push the aircraft at a 45° climb.

• Add larger elevator inputs near the last 90° portion of the ⅝ loop to prevent drift.

2. Downwind maneuver entry

• Higher entry angle (more than 45°) allows wind to push the model at a 45° climb.

• Larger elevator inputs near the beginning of the ⅝ loop prevent drift.

3. Crosswind

• Orient the nose into the wind with rudder.

Loop

1. Upwind maneuver entry

• Throttle changes to result in constant airspeed.

• Pitch input varies with more input while the aircraft is transitioning from the upwind to downwind segments.

2. Downwind maneuver entry

• Throttle changes to result in constant airspeed.

• More elevator needed during the first and last 90° pulls.

3. Crosswind

• Same as above.

Diagonal Humpty-Bump

1. Upwind maneuver entry

• Shallow (less than 45°) entry angle allows wind to push the aircraft at a 45° climb with steeper line segment after a half loop.

2. Downwind maneuver entry

• Steeper (more than 45°) entry angle allows wind to push the aircraft at a 45° climb with a shallow (less than 45°) line segment after a half loop.

3. Crosswind

• Same as above.

Reverse Tear Drop

1. Upwind maneuver entry

• Shallow (less than 45°) entry angle allows for proper flight path.

• Angle downline into the wind.

2. Downwind maneuver entry

• Steeper (more than 45°) entry angle.

• Angle downline into the wind.

3. Crosswind

• Same as above.

360° Aerobatic Turn

1. Upwind maneuver entry

• Increase throttle while traveling into the wind.

• Use pitch and rudder corrections to prevent drift.

2. Downwind maneuver entry

• Decrease throttle while traveling downwind.

• Use pitch and rudder corrections to prevent drift.

3. Crosswind

• Requires rudder and pitch corrections.

• Coordinate throttle inputs to maintain flight speed.

Humpty-Bump

1. Upwind maneuver entry

• The aircraft is oriented in pitch into the wind for a vertical flight path.

2. Downwind maneuver entry

• The aircraft is oriented in pitch into the wind for a vertical flight path.

3. Crosswind

• Orient the nose into the wind with rudder.

Immelmann

1. Upwind maneuver entry

• Different elevator amounts required during the transition from the upwind to the downwind portion after the first half of the figure is completed.

2. Downwind maneuver entry

• Increase throttle after the first half of the figure is complete. More elevator input required during the initial pull.

3. Crosswind

• Orient the nose into the wind with rudder.

Spin

1. Upwind maneuver entry

• The aircraft is oriented in pitch into the wind for a vertical flight path after rotation.

2. Downwind maneuver entry

• The aircraft is oriented in pitch into the wind for a vertical flight path after rotation.

3. Crosswind

• During entry and after the spin rotation, the model must be yawed into the wind to prevent drift.

Don’t overcorrect. If you do, a ½-point deduction per 5° of deviation will be applied to the figure. There can only be pitch and yaw angles.

If the pilot banks the aircraft in a roll, he or she will receive a downgrade of ½ point for every 5° that it is rolled. If a wind gust causes a sudden change in attitude, the pilot will not receive a downgrade and will be given the benefit of the doubt.

Closing Thoughts

Flying in wind is challenging for pilots and judges. With time, the required control inputs will become second nature. Keep the model safe and seek the advice of experienced fellow competition pilots when needed.

Until next time, fly hard!


Just as these two Mamba biplanes are hovering at a slight angle into the wind to prevent drift, pilots must apply the same logic to wind-corrected figures in IMAC routines.

SOURCES:

IMAC

www.mini-iac.org


1 comments

The author of this article described what average pilots can work on to be in control of their aircraft under windy conditions. While many modelers pack up and quit when the wind blows, some take the challenge and learn how to ‘kill the wind’ with skills honed by not being intimidated when it’s windy. Great article! Every pilot needs to control the wind and not let it control you.

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