Training landing gear

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A training landing gear (also called a trainer frame) is an aid that is often used to learn how to fly a remote-controlled model helicopter and is used to prevent the model near the ground from crashing in the event of minor control errors by the pilot, thus preventing damage to the model.

A model helicopter with a training landing gear mounted under the landing skids

Problem

Flying a remote-controlled model helicopter places high sensorimotor demands on the pilot, as often up to four directions of control movement ( pitch , tail , roll , nick ) have to be carried out at the same time in order to keep the flight model in the air. This is particularly the case with hover maneuvers , since the flight model is constantly striving in unpredictable directions and these movements have to be compensated so that the model does not pick up any speed in a certain direction or tilt away in the air, but continues to float in place. Beginners who want to learn to fly the model are often overwhelmed with correctly implementing these four control directions, especially in the phase of their first flight attempts. Especially near the ground, where the first flight attempts are naturally made, the flight model can be seriously damaged in the event of control errors, namely when the landing runners get caught on the ground, the model threatens to tip over or the main or tail rotor blades should come into contact with the ground.

The training landing gear is designed in such a way that in certain situations it should prevent the model from hooking or tilting and the rotor blades from contacting the ground, even if there is a control error.

Structure and application

A self-made training landing gear (tire version) under a model helicopter

Training landing sites are manufactured and sold by almost all well-known manufacturers in the model construction industry, but they can also be manufactured by yourself using relatively simple means.

It consists of an arrangement of two light wooden, metal, fiberglass or carbon poles , which are usually mounted at a 90 ° angle (cross) to each other. Balls or balls can be mounted on the outer ends of these rod assemblies, but there are also designs that are equipped with a hula hoop that connects all four outer ends with one another. The training landing gear equipped in this way is now mounted under the runners of the model helicopter, thereby enlarging the relatively narrow runners support surface of the helicopter many times over. This means that the model can no longer tip over to the side as easily when it comes into contact with the ground.

Due to the mounted tires or the balls at the ends of the assembly cross, the model can no longer easily hook onto objects on the ground (stones, branches, grass, landing carpet) or the ground itself, which would also have tipped the model over. In the best case, the tire or the balls slide over bumps and help to intercept the model and bring it back to a favorable starting position.

The training landing gear can effectively protect against falls near the ground. However, especially in the case of the variants with balls or balls, it can absorb system-related vibrations and pass them on to the balls and thus to the outer ends. This in turn can disturb the vibration-sensitive on-board electronics ( gyro systems ) so that the model no longer flies cleanly. In this case, care must be taken that the system-related vibrations cannot be transferred to the training landing gear.

Alternative learning methods

In addition to a practice-oriented learning of the control functions of the model helicopter on the free-flying object, there are also alternative methods for learning controlled flights with the training landing gear:

  • In order to extend or enlarge the support surface of the model helicopter, floats can also be mounted under the runners. These do not tilt as easily as the runners and also dampen the impact on the ground in the event of hard landings or ground contact. They have a similar function to the training landing gear, but are not always available for all model helicopter sizes.
  • There are also training frames in which the helicopter is mounted on a heavy frame and connected to it by a movable rod. The flight model can then be lifted to a fixed height (e.g. 20 cm) via this rod, which can be retracted or extended in the frame, and thus "securely" flies. A fall is not possible due to the connection to the frame. With these frames, however, the control commands and the flight position of the model are falsified because it is connected to the frame and therefore cannot make any free movements in the air. The drifting tendency described above in hover maneuvers does not apply, so that the student pilot only has to deal with this phenomenon when he is free to fly.
  • There are many flight simulators for model helicopters on the open market that can be used on the personal computer at home. In connection with a compatible radio remote control or a gamepad, you can learn to fly at home. Costly repairs after crashes are not necessary with a simulator, but the physical flight characteristics of the models are only modeled and can vary from the real flight physics and the characteristics of the real model helicopter, depending on the simulator software.
  • Flying can also be learned in a flight school . Flight instructors and trainee pilots couple their radio remote controls so that the instructor can intervene at any time and bring the model back into a favorable flight position if the model threatens to crash or if it becomes uncontrollable for the pupil depending on his or her flight skills.

Remarks

  1. ↑ The tire variant often comes as a self-made variant. The cross bars must not protrude from the tire, but must end with it, as they could otherwise get caught in the ground and thus have a counterproductive property
  2. ↑ The assembly must be done in such a way that the center of gravity of the entire model does not shift unfavorably. In the best-case scenario, it should be mounted in such a way that the helicopter in the air has no tendency to tilt over any of its axes
  3. ↑ The unfiltered practice in the open air with the training landing gear offers the advantage that the control inputs are actually passed on to the model unaltered and also the physical behavior of the model under the influence of all disruptive factors (e.g. wind, vibrations, solar radiation, distraction by spectators or other objects etc.) can be flown. The disadvantage is that the model can crash despite the training landing gear, which usually entails an expensive repair
  4. ↑ According to Section 16 of the Aviation Ordinance (LuftVO), a model aircraft is basically equivalent to a man-carrying aircraft and even designates a separate aircraft class
  5. ↑ the teacher flies in master mode, the student in slave mode. The teacher can neutralize the control inputs of the student so that he can take control of the flight model at any time

literature

  • Georg rods: DMFV helicopter primer . DMFV-Verlag, 2008, p. 13 ff .
  • Dieter Schlueter: remote-controlled helicopter . 11th edition. Neckar-Verlag, Villingen-Schwenningen 1999, ISBN 3-7883-3126-7 , p. 154 ff .