Ben Showers Skytwister Helicopter Plans
The SkyTwister Helicopter started out as a modified Adam-Wilson hobby copter designed in 1956 which was originally powered by a 650 Triumph Bonneville motor cycle engine of 40 HP.
At the time Ben was building the SkyTwister Helicopter, he (Ben Showers), a gentleman known as “Animal” and Jim Hodges of N.J. where all in a race to see who would get one flying first. Animal had a 750 cc Honda engine in his running 269 Hughes helicopter blades while Jim installed a Mazda rotary 12-A auto engine into his.
Ben got his to fly first, and now the one Animal was building is in a private museum in Hubbard org. owned by Jack Lenhardt. Animals Honda powered helicopter would try to hover but the clutches would not hold the main rotors load. Jims was completed and while heavier, had a lot of power, but little is known about whether it flew or not.
Ben had many failures with the SkyTwister helicopter during it’s development, he tried experimenting with different things including multi-blade tail rotors and other ideas that contributed to more then one to many forced landings.
The unfortunate side of R&D when building and test flying your own helicopter from scratch. He (Ben) taught himself to fly it in short time, and has recorded lots of video footage of him doing his early tests. In the video you can easily see it had good power and seemed real stable.
He once performed a public demonstration of his SkyTwister Helicopter flying it at the Mountain City Fly-In around the mid 90’s. At some stage during it’s development Ben encountered a sprag clutch failure which left him injured for some time.
This only drove Ben to refine the SkyTwister helicopter further and add safety improvements outlined in the following articles. What the end result was can only be seen as one of the cleanest looking scratch built helicopters of it’s time. (See Harold Wenrich’s SkyTwister “H”)
The following is a complilation of a series of articles and reports from different sources.
SKYTWISTER HELICOPTER TIMELINE
June 1991: started construction of Skytwister
November 1991: completed construction
November 1991: first tie down testing
May 1992: first tethered flight
September 1992: first untethered free flights
August 30th, 1993: accumulated time from first rotor spin-up 140hrs.
LAST KNOWN RECORD: accumulated time from first rotor spin-up 210hrs.
SKYTWISTER HELICOPTER TECHNICAL INFORMATION
BUILD TIME: approx 300 hrs. total (working part time)
ENGINE: 64HP Rotax L/C 532
DRIVE SYSTEM: clutchable multi-belt and chain
MAIN ROTOR RPM: 400
COST TO BUILD: $7,500
“CHOPPY” DESCENDANT UPDATE
Information was slim for me as our Pennsylvania weather kept me from doing much working out with my choppy this winter. I did get a few pictures. As I am sure, some who read January’s article on my project were skeptical as to and if my A&W style helicopter would even attain vertical flight.
Well, it does, as you can see from the tethered test flight (taken late Feb. 92). 20 some hours of various vertical hovers have been logged to date: Right now I have been working with various gear changes to achieve the best (marrying of the needles). Also tail rotor thrust is being worked with at this time. I have a suspicion my a-symmetrical main rotor blades create more torque than symmetrical blades do!
I have hours of work, and probably some changing ahead of me, not to count when it comes time for when the SkyTwister Helicopter transitions into forward flight, before I will consider my helicopter project complete (haste makes waste) Right? I promise to let you know (and some pictures) when I get to the un-tethered free hovering stage of my testing and training!
Courtesy Homebuilt Rotorcraft Magazine, July 1993
During hover attempts, and all hover practice, the A-symetric “flat bottom” blade is probably the finest rotor blade that you could ever use. However, a “WARNING” follows. Ben Showers has become a very proficient pilot with his Choppy SkyTwister A/W.
He has done some absolutely fine maneuvers with this A/W. However, upon forward transitional flight, he has encountered some terribly frightening sequences of events. The A-symetrical flat bottom gyro blade is strictly for gyros. Both Ben and myself have found this out.
When you mount this type of blade to a semi-rigid rotorhead, and vary the blade pitch requirements, such as on a helicopter, by using the collective to change pitch through push tubes, what you are really doing is changing the “Center of Pressure” on these blades and it can be deadly if you haven’t gone through it.
Your first encounter with this situation will begin as soon as you begin transitional flight. As you begin to leave the “cushion” and add throttle and a little collective, you will go – immediately – into a very hard right yaw, and as the yaw increases with collective you will become of with the “angel” if you can’t correct immediately.
Gently lower the collective, and get the ship into a hover as soon as possible. On symmetrical blades, the center of pressure is variable, hence the reason they fly so good. Again, the flat bottom blades are great for hovering, or slow manoeuvres, however, they are not for semi-rigid rotorhead flight.
For Ben Showers and myself, this has been a REAL learning experience. Don’t attempt this stuff, let someone else go first, and if they live … pay very close attention to their words of caution, for it will be they who dare, and try to give their knowledge to those who will listen and heed.
CHOPPY GETS HIGH
Courtesy Homebuilt Rotorcraft Magazine, October 1993
It has been a great summer here in Pennsylvania and flying “the pattern” is now past history! I fly my SkyTwister helicopter on average of once a week. The only major change that I have made since the last article was the rotor blades.
A newly acquired friend in Utah, by the name of Kent Culver helped me out with a set of 269-B Hughes rotors, which when modified to fit the A & W, proved out to make the Choppy a great flyer. Since, I had to change and “beef up” a few things along the way. But that’s to be expected.
There has been great interest in my SkyTwister helicopter and I have made contact with people all over the world. The farthest being Athens Greece! Along with flying a machine I hand built and meeting and talking to new friends, this project has turned out to be a Fantastic Voyage!
It’s sad for me to write my final article, but glad that things have worked out, and I accomplished finding the combination I needed to make my dreams come true.
My word of advice to others that may follow, is to take your time, almost to the point of dragging it out! I have said it before and I’ll say it one more time before closing. (Haste makes Waste)
And one more final note. Every time I strap myself in my SkyTwister Helicopter, I am preparing myself for another LESSON. When I cease to feel that way I will quit flying.
‘Till we meet again, lets all Fly Safely.
Single Seat Open Frame SkyTwister Helicopter
Bolt together 4130 steel and aluminum/aluminium tube main frame. A modified version of the original Adams-Wilson Choppy helicopter once marketed under the name “Polynova”.
Designed for the homebuilder, a true scratch built helicopter. Improvements and updates include aluminum/aluminium “tube tail”, seat tank and “composite” light weight energy absorbing landing gear plus new over run – sprag clutch for autorotation.
Belt and chain drive transmission system to convey power to the main rotors from a vertically mounted engine. Requires some precision machining for the main and tail rotor assemblies.
|Plans Built SkyTwister Helicopter Specifications|
|Engine||Rotax 582 LC|
|Power||66 hp – 48.6 kW|
|Main Rotor Diameter||21.5 ft – 6.55 m|
|Width||5 ft 8 inch – 1.72 m|
|Length||15 ft 9 inch – 4.80 m|
|Height||6 ft 8 inch – 2.03 m|
|Empty Weight||320 lbs – 144 kg|
|Take Off Weight||670 lbs – 302 kg|
|Useful Load||350 lbs – 158 kg|
|Cruising Speed||65 mph – 105 km/h|
|Maximum Speed||85 mph – 137 km/h|
Courtesy Homebuilt Rotorcraft Magazine, July 1995
“We also learned that Ben Showers, developer of the SkyTwister helicopter also crashed and sustained severe. Initial rumours of the accident ranged from Ben being in a coma to Ben being killed. According to his associate Jim Hodges, he is recovering from a broken back and several ribs.
The SkyTwister was totally destroyed in the accident, but Ben is already working (from his wheelchair) on a new “improved” ship. Jim said Showers will provide us with details of his accident in the near future.”
Courtesy Homebuilt Rotorcraft Magazine, July 1996
I guess you all may wonder how ol’ Ben Showers is doing? Well, pretty good I would say. I am working on many “SkyTwister” parts and am rebuilding my own prototype.
I will be testing a new design light weight composite landing gear that will absorb more energy in the event of a hard landing (that resembled a crash) similar to what I experienced a while back.
I am working with crutches now, which gets me out of the wheelchair. I have been flying, and doing some hover work with our new Hirth air-cooled model H “SkyTwister”.
There is much interest in this aircraft and could possibly end up being a “Kit Kopter”. But as I have been telling everyone, I will not make something available to the public, that I haven’t tested and “flown off” a couple hundred hours at least.
Ben Showers Aero “Skytwister” helicopter
Ben’s rework of the original “Choppy” homebuilt helicopter. He was one of the pioneers of adapting the lightweight two stroke engine to this craft along with innovations of the “tube-tail” and various other refinements to the landing gear and drive systems.
VIDEO: The SkyTwister plans built helicopter
CHOPPY HELICOPTER UPDATE
Courtesy Homebuilt Rotorcraft Magazine, January 1998
HERE COMES ANOTHER SKYTWISTER
A bit leaner, cleaner, and a whole lot meaner!, out rolls a new bird with new ideas and a bit simpler. Redesigned landing gear made up of fiberglass and aluminum tube lends itself to some suspension improving the capability to withstand that dreaded hard landing, or repeated landings, I should say.
Two great features are: a four pin pull which takes off all the gear allowing the entire aircraft to be carried through a doorway (make sure you turn the rotor blade lengthwise if leaving them on), and secondly garage wall storage, taking up very little space.
In the future I plan on designing a rotor strap assembly that will allow the rotors to swing over the tail boom for storage and trailering. This will make for a neat, small package, less than 16 feet long and less than 7 feet high. This will yield to a small trailer too.
A safety feature gyros have used for quite some time is a new item on the SkyTwister. It’s a seat tank with five gallon capacity. This is a beefy seat tank that provides the pilot with a large amount of back support for that, yes, hard landing.
It’s hard to believe, but there are now several factory-built, very nice, helicopter kits on the market. Pilots actually have a choice. These should have been here years ago. My SkyTwister is a true scratch-built homebuilt helicopter, in that the builder needs to make and construct the entire aircraft.
These kits, like the excellent Mini500, 254 UltraSport and B.J. Schram’s Helicycle are far superior and high-tech compared to my bird, but I feel I still have a place in the industry.
For the true homebuilder who still wants to build a scratch-built chopper and only has a limited budget I provide much information and a video on an actual flying example, logging hundreds of hours of test flights. I also manufacture some of the more complex parts that a builder possibly cannot make himself.
The very distinctive wedge style windshield – fairing used on prior SkyTwisters is retained on the newer machine. This yields good wind protection and style. It’s a see-through Lexan which only costs about fifty bucks. This is a low budget home built, right? I’m still using a Rotax LC in this machine, but with its lighter overall weigh an air cooled Rotax 503 or Hirth or 251 in the 50 HP range should do very well.
Doug Schwochert from Burlington, WI is flying a 503 Rotax in the AW’95 and getting the job done. I have quite a few builders doing the SkyTwister. One in particular in Dallas, TX is Lynn Darling. He’s doing a clone to my prototype, and it is looking good, the man does excellent workmanship.
He also does customer auto work that is super. I wish him and my other builders the best. I am willing to help anyone who has purchased my informational video etc. Any interested builders, refer to my advertisement in the display section of HR for rotor blades under Showers Aero for my mailing address.
A True Scratch Built, Ultralight Helicopter, You Can Build From Plans!
Homebuilt, Scratch Built, What’s That? In the world of small, homebuilt helicopters, I think that scratch built is almost a forgotten art. Small helicopters seem to be lost in today’s complex world. They are behind in technical information, etc.
However, there are a few stubborn people that really want to complete a machine that they really build themselves and does not cost a price most people can’t afford.
The SkyTwister, a small, simple and flyable actual helicopter does exist. I built and flew my first design in 1992 and have been improving this machine into an affordable, and yes, “totally build it yourself helicopter”, ever since.
It’s not for every one! Just looking at the plans may be too complex for some people. Hundreds of hours have been flown and many machines are now flying. It can be built for less that $10,000, which is a bargain compared to a regular kit chopper.
So, in closing, yes, a real “do it yourselfer”, plans or scratch built helicopter is still alive and well.
Lynn Darlings Skytwister Helicopter
It’s been several months since I last reported on the progress of the “Skytwister,” but as I had hoped…It’s all coming together! In the spring, I took a trip to South Mississippi Light Aircraft Co. and picked up my brand new Rotax 582 LC.
Being a teacher, it was a good excuse for me to do something on spring break other than occupy a space on the couch. Those folks had everything ready and it was a great experience dealing with them.
After I got the treasured engine back to home port, I had to deal with machining some more parts so it was back to Warner Machine in Lancaster, Tex. to do a bit more wheeling and dealing with the boss.
Wow! I can believe it, but it does fit correctly. What a concept!
Now this machine really is starting to look like something with an engine and blades sitting on top, so I really need to start building a decent looking instrument panel.
This is a deceptive part as it looks easy until you start trying to figure out what should go where to fit in what area and just how many of these cute, little do-dads you can afford to stuff in there.
I shortly came up with a few essentials—dual E.G.T., water temp, two tachometers, and a compass. After spending a couple of sleepless nights, I finally came up with an ideal layout for me. The engine installation went easy, but the dreaded shaft was now needed.
I knew I had to spend a “bunch-o-bucks” for the sprag clutch as I didn’t want to end up a statistic! So I opted for a Morse factory-built unit that was rated for three times more than I needed.
Better safe than sorry, right? So now I’ve assembled the side shaft and belts and clutching mechanism and am having all the fun of lining everything up so it fits. Wow! I can’t believe it, but it does fit correctly, What a concept! The pictures really show that it is a simple, but mechanically sound, little design.
The paint job was the easy part for me since that is what I teach. A little tape here, a little paint there, and it now is starting to get a little more attention from the guys who initially said, “You’re gonna build a what?!!”
Everybody seemed to be a heckler at first. Now at this writing, I’m in the process of wiring it up and finishing the radiator system. I ‘m not going to rush through this part, but am very eager to hear the Rotax crank up and ROAR, or maybe just purrr like a kitty for awhile. Several people have come bv to see how it’s progressing and I’ve gotten many nice comments on the bird so far.
PLEASE NOTE: Ben no longer seems to be contactable regarding his SkyTwister helicopter creation. No further information has been available even after repeated attempts to contact him. It is also believed he has moved from his last “advertised” address.