Bacon and eggs, chocolate and peanut butter, salt and pepper; some things just go together. You’d think that a mashup of an airplane and a helicopter would be great, right? The Fairey Rotodyne was just such a thing from the late 1950s and while it looked to be the wave of the future, it never took off — at least, not in the business sense at least. [Mustard] has an excellent video about the machine including some flight footage and explains why it failed to take over the aviation market. You can watch the video below.
While it does look like a helicopter mated with an airplane, it’s actually a bit different. The rotor isn’t normally powered at all. However, it does turn in forward flight and generates about half the lift the plane needs. That explains the stubby wings. The topside rotor has small jets at the tips that can be used during vertical take off, landing, and hovering modes.
For its time, it was fast and efficient, especially compared to contemporary helicopters. This type of plane was known as an autogyro and actually appeared in the 1930s as a safety mechanism since an autogyro can land in an autorotation mode.
According to the video, the noisy tip jets and production delays killed the beast. There was only one prototype built, but there was something we found very attractive about it. There have been, of course, other autogyros. British, German, Japanese, and Russian military have used autogyros at one time or another. The United States Postal Service was known to employ at least one.
Even today, there are about a thousand autogyros used by different military and police organizations. They are cheaper than a helicopter to buy and fly. Sadly, though, it doesn’t look like autogyros will ever become a common sight. Like an airship, they seem like a callback to an earlier time when you have a chance to spot one.
We are always surprised we don’t see more model autogyros. We wonder how they’d be at cutting down trees.
A friend built a small helicopter that also used tip ram jets. To simply say it was LOUD is such a huge understatement. It was loud enough that if you parked a car too close you risked the sound cracking the glass in it. The Rotodyne used much larger tip jets and call me crazy but I can’t think those were quieter lol. Even if it had managed to find landing spots where everyone was atop a tall building you would definitely hear it coming day or night. If you look at some of the other VTOL concepts out around that time you see the roots of the Osprey which makes a lot more sense.
Turns out they were quieter, this is discussed throughly in the video.
How about a standard helicopter engine, standard airplane jet engines on stub wings? Vertical takeoff then when the jets and wings provide enough lift, switch off the helicopter engine and let the blades autorotate. Seems like it would be more efficient than a helicopter but also give the VTOL a plane lacks. Best of both worlds. Am I wrong?
The only way to determine if you are or are not wrong is with a design study, I doubt either of us are willing to commit that much effort to this discussion. However, if you are on to something you might have the chance of a lifetime.
That is what the Rotodyne was. Precisely that.
Gyrocopter girl ;-)
All helicopters can land in autorotation mode. Pilots get tested on it.
Small autogyros (aka gyrocopter) are cool, but there is a massive gap in the price ranges of them, unlike light fixed wing (LSA, Ultralight, even just light single GA)
With light fixed wing you can get a bugs in your teeth wind in your hair for a couple thousand, a simple but comfortable enclosed machine for a 10-30k, or a real fancy modern machine for 80k+
With an autogyro you can get something resembling a washing line with a seat for a few thousand but then there’s really very little until you hit big money – even at 50k you’re still looking at open cockpit realistically for anything remotely modern (and there’s very little older stuff, Mucolloch J2, RAF 2000 and…. not much else), if you want an enclosed cockpit autogyro you are realistically looking in the 70k+ range at least.
It’s simple, buy a normal helicopter with a broken engine. Sell the remains of the engine and there you go, one autogyro! ;)
Mustard videos are always really good : the quantity and quality of work in the graphics are impressive !
I like them, especially when they have a model sitting on a table.
Noisy tip jets going thru giant Leslie speakers in the sky! That would spread the sound of those jets up and down the sound spectrum. It’d make for a great movie sound effect of a UFO. I wouldn’t like to maintain the seals of the jet’s fuel line to the rotor.
Good thing there’s no fuel line.
Oddly enough in the original Tom Swift Junior novels, he designs and flies a bird a lot like that. There it is called a “heliplane”.
The big draw for the autogyro is safety. Flight is slow and If all power is lost autorotation still continues so you simply pick a landing spot… Immediately! Rig it up with a dead-man throttle and the pilot can die in flight and it will still make a soft landing on it’s own provided it does not strike a tree, pole, or wires.
High wing R/C models, the wing can be removed to rig it up with a single mast holding stacked counter-rotating blades and it works fine. We had a couple summers of fun with them.
I don’t think autogyros would be much good at cutting trees; while they can autorotate, they really can’t hover because their rotors get their power from the airflow in forward motion. Sure, with tip jets they can hover, but then they’re helicopters, not autogyros.
I’m pretty sure all that i information is in op. Good job with the redundancy.
I’m pretty sure I was responding directly to the last sentence in
the article, so even though the answer was IN the article, it was lost on the author.
Thanks for the unnecessary snarkiness.
The remains of the Gyrodyne prototype with blade and tip jet are in the Berkshire Museum of Aviation in Woodley near Reading, UK (http://museumofberkshireaviation.co.uk/). This was an R&D precursor to the Rotodyne flown at White Waltham airfield. The museum reflect the long history of aviation in Berkshire has a fascinating array of exhibits including a Polaris Chevaline warhead and many from the Miles company that was based at Woodley.
Oooooooooh! Awesome!
That place is great, full of mould-timers who understand and want to talk about the stuff in there.
*old-timers.
Thanks autocorrect! 😭
Thanks, I prefer to think of myself as “crusty” as opposed to “mouldy”.
B^)
I remember seeing a tiny one of these at the Farnborough Airshow as a kid. It was being sold for special forces use. It was pretty much a chair, with a tank of peroxide strapped in the void beneath it, and the blades coming out just above head height.
I’m guessing it was just a prototype, and they never got any sales.
I am happy to see a well deserved reference to Juan de la Cierva, the spanish engineer who invented autogiro en 1920, in this video
https://en.wikipedia.org/wiki/Juan_de_la_Cierva,_1st_Count_of_la_Cierva
In my 1970s childhood the big talk was of STOL instead – airliners that could use only short runways. This didn’t change the world, because it turns out a lot of the space needed for an airport is taxiways, the ramp for parking, hangars, a vast car park, terminals, &c., and having shorter (or, in the Rotodyne case, non-existant) runways doesn’t really make much difference.
Turns out that for certain applications you’re wrong.
Oh, I see, you’re just kind of a dick. Never mind.
Wavv! Awesome!
That place is great, full of mould-timers who understand and want to talk about the stuff in there.
As Randall Munroe put it, “autogyros are weird.”
https://xkcd.com/1972/
And well, I can understand why, strange that these odd things haven’t become more popular, though they don’t look like they would instill a lot of confidence in people, so I guess that is the main reason why.
I’d be thinking about one if I had a place in the country with a few hundred feet of back yard. I was actually at a yard sale at such a place and there was one in shipping boxes in the barn, didn’t find out how much that was going for, it might have been a tow behind version, couldn’t see engine or mounts. I didn’t get real anxious to find out, because all other equipment seemed to be 80% of new price at 20 years old, so I was like “Heh, good luck with that..”
They’re also a little bit special-use: if you have the space for an autogyro runway, you have the space for a bushplane, with better speed and range. It’s also somewhat difficult to get training in a gyro. Almost every airport that has multiple aircraft at it has a fixed base operator that offers training. There’s nobody offering autogyro training in my state.
If they called these things ‘loud’ in the 1970s they must be deafening now :) They had very different ideas on noise pollution back then.
Also, the tips are probably the worst place you could hang something as heavy as a jet engine :P I wonder if this design would have worked better if it had been centrally powered like a normal helicopter.
Inertial loading out on the tips is bad, but since the tips are where the lift is, putting some weight out there is better than hanging all the weight off the slow end of the wing. Plus these were really lightweight, as the compressors were in the aircraft body. All that was at the tips was a mixing system and an expansion nozzle.
I don’t see how it’s a bad thing to increase moment of inertia – rotor inertia is essential to safety in any rotorcraft, since this is where the energy is stored that makes autorotation possible. At the tips gives the most angular momentum per unit mass.
Probably backwards thinking from normal heli, because when applying torque from the hub you’ll get nasty shear stresses and a tendency for your blades to want to twist out of true pitch if you have heavy tips. Though it may give you grief with vibration damping and undesirable gyroscopic effects.
There were no jet engines on the tips.
Your link for cutting down trees involves no cutting down of trees.
Rebuild it as a hybrid and use a motor/ generator instead of tip Jets
Simce it would be short duration and high intensity usage, you could probably get away with a modern electric motor, a smallish lipo battery bank, and leaching power off the primary engine’s for in flight recharging.
Makes me wonder if a quad copter would be efficient with horizontal prop for forward speed and feathering the “lift” props.
the should use engine or electromotor instead tipjets
If we applied modern design technology to this system, what could we come up with? I like the “can’t easily crash” idea.
“The United States Postal Service was known to employ at least one.”
Not sure this qualifies…
Florida mailman lands a gyrocopter on Capitol lawn:
https://www.youtube.com/watch?v=8cXyRzT4hBw
Tip-jet craft (Gyrodynes) are not Autogyros in the same way a Helicoper in autorotation is not an Autogyro. Then you have things like the Hughes XH-17, which is technically termed a What The Hell Is That Thing.
XH-17: First reaction: I’m thinking it would take more than a couple hours of training and experience to set that thing down straddling a truck.” Then I realized, you land it first, then drive the truck under it. Stupid brains.