From XH-1 to Mi-12: Rotary Winged Adventures in KSP

[Goddess Bhavani]

"From XH-1 to Mi-12: Rotary Winged Adventures in KSP"

Part of Kitten's Aerospace Musings

Chapter 1: Airwolf

Hello, I'm pandoras kitten, one of the silly people who thinks watching things move round and round like the wheels of a bus is a practical method of sustained flight.

Rotary winged craft have been a part-time obsession of mine in KSP ever since I discovered the Infernal Robotics mod.

I wish I could find a picture of XH-1, an experiment to see if KSP's aero model can generate an appropriate amount of lift (and realistic torque) from a rotating airfoil. It was simply a thrust frame with a IR powered docking washer on top with a pair of swept wings stuck to the side. Lo and behold, XH-1 worked perfectly fine, albeit using an SAS module to provide countertorque.

To work around the countertorque issue, I decided having two counter rotating rotors would be a simple solution, and set out to create a synchropter very loosely inspired by the Kaman K-MAX. I also decided free-spinning, tip-jet propulsion would be an interesting thing to try, resulting in my first helicopter video set to the soundtrack of Airwolf.

Chapter 2: Triebfluegel

Rotary Rocket on Wikipedia

Shortly after, reading up on tip-jet propelled craft led me to the startling realization that an externally driven rotor does not need counter-torque, beyond what is necessary to compensate for rotor bearing friction. My pursuit of all things whirly led me to the Rotary Rocket Company of Mojave in the Year 2000, where the Roton Rotary Rocket was test flown and reported to be something like -the- most difficult aircraft to fly, of all time.

Externally driven rotors are not a new concept - the Focke Wulf Triebfluegel concept of World War 2 envisioned a "thrust wing hunter", a tail-sitting, jet rotor propelled VTOL interceptor that would not need airfields.

This inspiration of course, let to my own "thrust wing" prototype, the XRR-1 Rotary Rocket which attempted to pick up where the real Roton left off - a rotary wing assisted SSTO tailsitter that never got anywhere for real as KSP test pilots would report being scared out of their wits seeing so many huge, heavy parts rotating at absurd velocities!

The XRR-1 also had a unique ability to transition to fixed wing flight since KSP rotary wings are inefficient beyond a certain speed - cruising at Mach speeds on the tip jets it had the option of operating as a VTOL kerbinside and it could perform unpowered landings after re-entry by autorotation alone. This makes possible future non-parachute re-entry solutions using the latest Infernal Robotics Rework parts.

The X-Wing Rotary Rocket as it was called, also got the showcase video featured on gaming blog Kotaku!

Chapter 4: Synchropter

With the release of KSP 1.0 came a new near-stock installation of KSP. ZodiusInfuser of Infernal Robotics Rework also requested a near-stock synchrocopter (synchropter) so out came the KE-2 "Mosquito" synchropter which promised reasonably brisk short range passenger and light cargo capability. However, the intermeshing rotors proved to be less than practical in operation, creating a high level of inflight vibration due to the low speed rotor design.

Chapter 5: Edge of Practicality

To remedy this, a

was drawn up in short order after I watched the Boeing-Vertol V-44 Quad Tilt Rotor (QTR) in Edge of Tomorrow.

Skirting the "edge of practicality", the QTR concept worked flawlessly in 1.0.2 but was non-functional once the aerodynamics was once again altered in 1.0.4, greatly limiting the V-44's top speed. It is notable that we can't do the kind of torque-vectoring control necessary for successful quad-copter operation in KSP, but I did master the art of constructing fully articulated folding rotor blades! Phew!

Chapter 6: Mil V-12 / Mi-12 "Homer"

Finally, we've come to the present cutting edge offered by Kitten's Aerospace Musings - a working replica of the record-breaking Mil Mi-12 design, which, as the V-12 prototype in 1969, achieved FAA-authenticated fame with many payload to altitude records.

Designed to ferry strategic missiles to remote launch sites, the Mi-12 "Homer" could carry 40 tons of payload and served as inspiration for the fictional "Hotelicopter" which took the Internet by storm.

Although it's unlikely to see service as a general purpose heavy lift VTOL due to its very complex and precise manner of operation, the Mil V-12 Replica represents the pinnacle of my short helicoptering career in KSP, with silky smooth, vibration free flight, high efficiency turbo-electric hybrid propulsion and a yet to be tested oversize cargo lift capability proposed as a means to transport low cost prefabricated Kerbal housing to remote locations.

Edited September 6, 2015 by pandoras kitten