KerbalX

Since my last visit here, they fixed the wheels load parameters and now they break at the slightest bump and the front wheel is not touching the ground. For the moment, unfortunately, I don’t have the energy to try to fix this.

Details

• Type: SPH
• Class: aircraft
• Part Count: 135
• Pure Stock
• KSP: 1.9.1

Built in the SPH in KSP version 1.9.1.

Description

With this design we moved on from the Bensen’s age, to the modern era of gyrocopters. Meanwhile the principles of flight remained the same - a free spinning rotor to provide the lift and a powered propeller for the forward thrust.

To fly

1. Activate SAS and hit the Brakes
2. Press [Space] to start main rotor prerotation. Wait ~20sec, let the rotor build some speed, preferably above 200 rpm
3. Set full throttle and let it roll for take-off. Starting from 25m/s you can pull on the stick. As I said in the notes section, sometimes the craft is poorly initialized with a strong tendency to bank on the left side. In this case you have to relaunch.
4. During flight use the throttle to control the aircraft pitch attitude and/or the rate of climb/descend.
5. Starting form ~1000m altitude it may require to trim the inner propeller angle to 16-18° to prevent the craft to roll on it’s right side .
6. Work with the throttle and pay attention to the airspeed as this is the only thing that keeps the main rotor spinning; in dives or other flight maneuvers try not to exceed 50m/s as the rotor rpm will decrease very rapidly becoming unable to maintain the lift

Notes / Revisions

• Rev.1:
  • resized the prop engines to do a better job of canceling each other’s torque rotation including the vertical rotation caused by the dissymmetry of lift in the main rotor. Still not perfect though, as the magnitude of those forces is a function of altitude (air density), hence the need for trim adjustment of the propeller with altitude. Moreover, sometimes the craft is spawned having a strong tendency to bank on the left. Unfortunately, I haven’t figured out the cause. On those occasions you just have to relaunch.
  • aesthetics improvements
• Unluckily, the initial version including the rotor tilting device didn’t work satisfactory enough to be published. The hinges, the linkages and the whole thing was way too bendy under the stress requiring much more control inputs especially in the absence of a joystick. Seems KSP just hates 100% rigid joints which is ridiculous. I picked the reaction wheels instead, which, in conjunction with SAS gives a much confortable control using just the keyboard.
  
• For some unknown reasons (and totally unintended) the battery that was supposed to power the engines never get drained; the craft can fly forever
• The gyro also has a bit of a wheel-borrowing problem I could’t address without sacrificing other flight characteristics
• As I already wrote in my previous craft descriptions, the autorotation in KSP occurs very different than in real life mostly because the KSP (or Unity, idk..) physics engine completely ignores the concept of airfoil. Therefore, in this regard, any simulation of a craft using autorotation in KSP is somewhat limited.