Radio-controlled aerobatics is the practice of flying radio-controlled aircraft in maneuvers involving aircraft attitudes that are not used in normal flight.
Inside loops
Due to its simplicity, the inside loop is among the first aerobatic maneuvers a pilot learns. It is named after a 360 degree circle with the pilot on the inside of the loop. Simply applying power while pulling back on the elevator stick will cause the aircraft to loop upward into vertical flight, continue into inverted flight, continue into a dive, and return to horizontal flight. A well-performed inside loop will look like clean circle with the same entry and exit point, and this requires management of power to overcome the tendency of gravity to shorten the upward portion and lengthen the downward portion.
The inside loop is performed by: starting from level controlled flight increasing power to maximum and applying up elevator in the amount that yields desired loop curvature reducing the up elevator input to maintain loop curvature at the 2nd and 3rd quadrant reducing power at the 4th quadrant while adjusting elevator input to maintain curvature pulling back to level flight and increasing power while returning elevator to neutral
Outside loops
An outside loop follows the same path as an inside loop, but is performed with the pilot or cockpit on the outside of the circle the aircraft describes.
Therefore, if the aircraft starts in a normal, upright flight position, then an outside loop will be performed by inputting down elevator and progressing down below the original line of flight before executing a circular path to return to the original position. This is sometimes referred to as a 'bunt'.
Outside loops generally require more power and a higher control input than inside loops to perform because the lift force is in an outwards direction, thus tending to pull the aircraft out of the loop.
Immelmann turn
The Immelmann turn is named after flying ace Max Immelmann. It has become one of the most popular aerial maneuvers, being commonly used in airshows all across the globe.
To execute the Immelmann turn, the pilot pulls the aircraft into a vertical climb, and eventually completes half a loop in the aircraft from this climb, inverting the aircraft. The pilot then executes a half-roll to regain level flight.
The Immelmann turn can also be reversed by starting with a half-roll into inverted flight, and then using elevator to pull the aircraft down through a half loop back to level flight.
In both cases, the aircraft has changed course 180 degrees and exchanges speed with altitude.
Inverted flight
An aircraft is in inverted flight when it has rotated 180 degrees about its longitudinal axis, so that its cockpit and tail fin are pointing at the ground.
Inverted flight in itself is not generally regarded as a maneuver, rather as an attitude in which to perform other aerobatic maneuvers. Therefore, an inverted maneuver is one in which the aircraft begins in an inverted flight position.
There are many ways to enter inverted flight. The simplest is to
begin from straight level flight, increase power if necessary, depending on the aircraft, roll the aircraft with aileron control while maintaining heading with slight rudder and/or elevator input, neutralizing aileron when inverted, apply slight down elevator to maintain level inverted flight.
When in inverted flight, elevator and rudder inputs are reversed while aileron and throttle input remains the same.
Alternatively, one can enter inverted flight by performing half an inside loop or half an outside loop.
Intermediate RC maneuvers
The intermediate maneuvers, not suitable for beginners, require skills acquired by considerable practice, and often include the use of stalls. Trainer aircraft are not suitable for these.
Stall turn
In a stall turn the plane goes upward, decelerates, yaws 180° under stall, and comes down nearly the same path it goes up, as if it gets hammered on the head.
To perform a stall turn;
From level flight input up elevator and reduce power until the aircraft stalls. The angle, speed, and abruptness at which stall occurs depends on the aircraft. As the aircraft stalls input full rudder to one side. This will swiftly swing the aircraft through 180 degrees, gyrating in yaw about the inside wing tip with gravity-induced angular momentum. Release the rudder input before the yaw completes 180 degrees to prevent yaw overshoot On the downward heading gently input up elevator until the aircraft recovers into level flight.