Autogyro study aids
 

I'm set up to go on a course to learn to fly an autogyro. It's in France, and the only study guide I can find is a generalised microlight guide, which I already have (this is an add on rating to a microlight PPL, also French)
Can anyone point me at a good guide to flying the beast? I don't need the rest of the stuff such as law and met, but some aerodynamics related to autogyros would be helpful. English or French language. I'm currently flyiing fixed wing, power and gliders.

Most commonly used ones in the UK are Home or the books by Phil Harwood ("Flying The New Generation Gyrocopter").

The Flight Manual is also a useful (and often overlooked) resource.

Glasgow university did a study on the aerodynamics a few years ago, based on the bad accident rate at the time.
May be worth looking into. Sorry, don't have a link.

Quote:

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Glasgow university did a study on the aerodynamics a few years ago

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https://publicapps.caa.co.uk/docs/33...2009_02red.pdf

356 pages!

Not sure what this tells you, but the chap who ran the Glasgow study now works for Loganair ! I've read most of his papers, but they're not as easy reading as the CAA work, nor frankly likely to aid you in learning to fly an gyroplane much.

G

British Rotorcraft Association should be able to help.
My limited knowledge of them, they are great fun if flown correctly, some control inputs are completely the reverse of fixed wing, helicopter pilots may have trouble with going up in autorotation, fixed wing pilots, blade stall recovery, pull and pitch up, negative "g" is usually fatal.
Good training is vital.

Standby... Some control inputs are completely the reverse of fixed wing.... err like what?

Like all aircraft the text book is of less use without the practical context. Best advice is to find an instructor and then let him guide you to appropriate text. Beyond all of that they are very benign to fly. Landing is pretty much as fixed wing, except the gyro is a drag machine so there is little float after rounding out. Take off requires understanding of your particular aircrafts pre-rotation process and then some practice going through the take off roll, wheel balance and airspeed build up post unstick. Upper airwork wise as has been said zero and neg g are not possible due to rapid rotor rpm decay (think drag) but then non aerobatic pilots never get into that condition fixed wing wise so its not as big an issue as it sounds. Overall great aircraft, under rated and yet for 90% of GA arguably the most suitable aircraft available.

Pardon me, "some inputs the reverse of fixed wing" . If you get into a situation of rotor RPM decay, which is similar to a fixed wing stall. You do not push and increase power, fixed wing fashion. You pull and reduce power to increase the drag through the rotor. This was explained to me during the very small amount of training I did on them. The words used were, " get the disc loaded and keep it loaded.
Sorry to ruffle feathers.
I am no expert on this, never professed to be, and I am not about to argue with a gyro pilot. As I said, my (limited) knowledge of them.

I should add that my limited experience of them was well before the Glasgow investigation. In the days when the thrust line/CofG was more of a problem. Although it was understood.
Modern, lowered thrust line, designs are far safer than the old Bensen B8.

Thanks everyone. That should be good

crash - all is cool but personally I just wouldn't describe things as reversed. Forward stick still pitches the nose of the aircraft down, back stick pitches nose up. Right and left stick still roll the aircraft right and left.

Low rotor rpm in a [functioning] gyro is not possible without unloading the rotor - which either means pilot induced [via forward stick] or a great deal of turbulence [the likes of which would not be ambiguous!]. However that is not a stall. I'm unaware of any gyroplane flying that has the ability to stall the entire rotor, certainly not one being operated within the limitations of the POH.

I agree that a very nose high attitude could create the differing response if indeed your fixed wing response is to push rather than simply release the back stick...I'm just not sure I'd describe that as the reverse its just a different response.

Like I said before - take a look at the Gyropedia link above and / or read Phil Harwood's books. They are the standard texts in the UK and have been translated in to many other languages.

Don't take too much notice of what you see written by aeroplane pilots on forums. I'm sure Crash One is meaning to be helpful but in the nicest possible way his posts aren't doing a very good job of explaining how to handle a gyroplane.

For most of the flight envelope a gyro handles very similarly to a light, draggy aeroplane. It's when you get to the edges of the envelope that things change and life gets more interesting (and much more fun!).

Enjoy your gyro flying!

Pittsextra.
I didn't mean control function reversals, I meant the action taken with them!
Fixed wing stall recovery, you pitch down, obviously by pushing.
With the gyro you pitch up, obviously by pulling.
Crossed wires here I think. NO not control wires!

Unless of course we really confuse the issue and go really far back to the old Bensen with that overhead inverted T bar that really did work the same as a flexwing micro!!!!

And as I said, limited experience of them.
I'm not trying to explain how to fly them, I just know they can, I repeat, can, bite at the edges of the envelope. I'm not surprised that the newer ones are benign, that's what the Glasgow investigation was about.
As for them flying like a fixed wing, no thanks, if I bank my taildragger to 80 deg and pull hard it will stall, I don't think a gyro will do that, if I landed by pulling till it nearly stopped 3ft above ground I think it would retract the gear, violently! correct me if I'm wrong.

Crash, I've got a lot (lots and lots!) of time on gyroplanes, and a reasonable amount of time on aeroplanes. Like I said - most of the flight envelope is similar to a fixed wing, it is around the edges of the envelope where it differs. High bank turns are, by most definitions, "around the edges", and if you flare a gyro 3 feet above the runway you are unlikely to have a soft landing.

I suspect you mean well but your posts really aren't very helpful to someone thinking of starting to fly a modern gyroplane. By your own admission you have very limited experience based on an old-style machine. I don't think many people would consider themselves qualified to comment on the flying characteristics of a C172 based on a few hours experience many years ago on a Tiger Moth, but somehow a couple of hours on a gyro seems to make everyone an expert ....

The Glasgow University research hasn't been very well regarded by the industry and has had little impact on modern designs. Glasgow told us that the way to get stability was by having the thrustline close to the vertical CG, and that horizontal stabilisers have little effect on stability. Most modern factory-built gyroplanes have a larger thrust line / CG offset than the one recommended by Glasgow and have great big horizontal stabilisers .....

Look guys, I just wanted a pointer to a decent textbook or two. Can we save the pistols at dawn for , oh, I don't know, adultery, or heresy or something?

Learn all you can;
 

The more you understand how your autogyro works, the safer you'll be;

https://www.faa.gov/regulations_poli...-h-8083-21.pdf

Chapter 15 and onwards is for autogyros.

Flying gyros near the edge of the envelope is not advisable.
There is plenty of fun within it.

I built my own and taught myself to fly it. Great fun. Not a route for the impatient or careless.

The machines are safe. The pilots are the problem.

I'm guessing that only one of us read those papers?

G

It was good few years ago now ... happy to be corrected!

From CAA Paper 2009/002:

Next on my list.

I dunno,Back in 1983 just a few circuits with Ken Wallis in the 2 seater ( WA117) ,then off I went and got my licence. I had seen Pee Wee Judge go in at Farnborough in the early 70's and so was wary of neg "g". Then never any problem with the Wallis design. Mind you I never ventured to the limits of the envelope.

Phugoid is not, so far as I know the major issue with gyroplane LoC / in flight failure - that tends to be SPO related, sometimes with linkages to vertical motion of the pitch inceptor. IIRC, the Glasgow research papers (not the CAA interpretation) looked mainly at SPO and LSS, not the LPO, and were very much about modelling of gyroplane stability, not airworthiness recommendations, which were CAA conclusions (with the exception of the 2" rule of thumb, which IIRC did originate in Glasgow).

A tailplane is fairly self evidently going to damp the SPO, and thus will have a beneficial effect on the risk of LoC. Because the phugoid is nominally constant AoA, you'd not expect it to have all that much effect, unless it incorporated an elevator.

G

For the benefit of "this is my unsername"
I did spend about a year helping a friend of mine figure out why his Merlin wouldn't fly properly. Rotor pitch angle seemed to be the problem, after much faffing around machining new head plates, pitch control bars, etc thinking it had been set up incorrectly, we put an inclinometer on the mast.
At the bottom end it was correct, at the top it was angled forward of correct by 5deg and bent sideways 3deg.
Some investigation from previous owner revealed it had fallen off a trailer into a ditch!
An "engineer" (gyro) fixed it, signed it off. The owner operated out of a long Tarmac strip I believe so didn't notice the lack of pitch up control and sold it in good faith.
So having spent a while involved in the principles I'm not quite devoid of knowledge of them. Fixed wing pilot or not.
Question.
The Ken Wallis designs all had relatively short masts compared to later ones.
He could push the rotor round while strapped into the seat.
Looking at the side view of photographs of them they seem more "longitudinal" rather than "vertical" in profile, for want of a better phrase.
How does the high mast affect pitch control?
Would an unloaded rotor have a tendency to accelerate/rotate around the CofG when it has a longer moment arm?
Going fixed wing mode for a minute, the thrust line/lift line are not very far apart.
Gyro mode, there is a considerable vertical distance between thrust line and draggy rotor lift plane.
I may be out of order, all wrong, but if so can someone please explain why?
Being a fixed wing pilot doesn't make me ignorant of the gyro and I object a bit at the "expert" remark. I don't need to fly one for hundreds of hours to understand the principle, so can we drop the "fixed wing pilots know bugger all about them" thing please?

The original Bensen was powered by a high-revving 2-stroke drone engine with a small direct-drive prop, and as a result the required rotor to prop clearance could be achieved with a relatively short mast. I'm told that this put the thrust line of the engine on the original Bensen was pretty close to the vertical CG - as per the later Glasgow recommendations. Some of the later Bensen derivatives were fitted with geared Rotax 2-strokes fitted with gearboxes which allowed longer, more efficient props to be fitted, requiring a taller mast. Whilst the taller mast did have the effect of raising the CG, that was somewhat counteracted by the engine being lower relative to the thrustline due to the "cranked" nature of the gearbox and the engine thrustline moving up - and so a significant offset between the vertical CG and the thrustline was introduced. The original Merlin with a 582 and relatively light rotor blades had some interesting handling qualities - for example it would pitch significantly nose down when power was applied and pitch nose up when power was reduced.

In aircraft with a high engine thrustline relative to the vertical CG then unloading the rotor (eg by rapidly pitching forward and reducing "G") whilst at high power settings can result in the aircraft pitching nose down as a result of the pitching moment of the thrustline around the CG when the drag from the rotor reduces. This in turn can result in a further reduction in "G" resulting in an increasing pitching force and if uncorrected can have a very unhappy outcome. Most modern designs seek to address this by bringing the engine thrustline closer to the position of the vertical CofG and/or use of a horizontal stabiliser.


Homebuilt gyroplanes can be put together with a range of different engines and props and are operated by pilots of varying weights. When they are built they are subject to a "hang check" where the aircraft is lifted by the teeter bolt with the pilot and a typical fuel load on board to check the angle at which it hangs. The reference for the angle (eg mast or keel) and the acceptable range vary depending on the design. A gyro with, for example, a heavy pilot and a light engine/prop will hang nose down - meaning that in normal flight the rotorhead will be operating closer to it rearward limit of movement than it would be with a light pilot / heavy engine. That can becomes an issue when flaring to land as the pilot may run out of rear stick travel before the rotors are at the required pitch angle for the flare. Conversely with a nose-up angle the pilot may run out of forward stick movement limiting the speed of the machine. The normal adjustment for this is to move the position of the rotorhead forwards or backwards until the required hang angle is reached.

I agree with all of that.
It seems that any increase in power, larger dia prop, is going to cause problems as the mast gets longer.
Somewhere about 30 odd years ago I had the quaint notion that a smaller dia ducted fan system might work.
I built an enclosed turbine motor device about 4 inches dia, ran it on compressed air at 10bar and got about 12000 revs, no load, still got it somewhere. The idea was to use a series of fans in a Venturi tube, prob about 3 feet dia 2 feet long driven by a hydraulic pump/engine. Two of those side by side driven off one decent engine placed wherever suited the CofG.
The whole idea was to get the rotor/mast down as close to CofG as possible.
I never got the chance to build anything so it remains in the daft ideas tray.
I still think the rotor drag is not being considered enough. CofG and thrust line, yes but that long mast bothers me.