Thinking About a Gyro

I daydreamed about those things for a long time a while back.....
seems like they'd be fun, and a relatively inexpensive way fly.... extremely versatile...and very safe if flown conservatively.
I think the thing that spoils them for me is that they seem to fit into a "re headed step child" area in terms of the regulations. Seems to limit the potential utility a lot....
 
jesse said:
Roger. I've seen a lot of examples of well less than 300 ft, along with manufacturers claiming well less than that with a pre-rotator. Are you saying that's not possible or safe? Or are you saying they are all lying about the performance?
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I think there is a manufacturer or two that claims 300 ft (AutoGyro Cavalon?). Others claim this is bunk, even with a prerotator that spins up to 300 RPM. It's not the kind of thing I'd want to depend on. The issue with gyros is that the angle of the rotor is what causes the rotor to spin up faster, not the speed of the gyro. At the same time, the gyro needs to be moving at a speed fast enough for the rotor to spin up and wheels to lift off the ground. If the rotor speed is too slow compared to the gyro speed, the blades may even slow down and/or flap (it seems a vast majority of accidents happen because the pilot forgets to pull the stick back prior to accelerating). This would be a very bad day. So if you don't execute the process perfectly, you may not get off the ground in the expected ground roll. If you don't have a margin of error, another bad day. My POH say 270-400 ft. Maybe with a lot of practice I'll be comfortable with 400 ft...

A lot of the videos you see with ultra short short takeoff rolls are into high winds. You won't see them taking off from a field that's only 300 ft though.
 
MonkeyClaw said:
I think there is a manufacturer or two that claims 300 ft (AutoGyro Cavalon?). Others claim this is bunk, even with a prerotator that spins up to 300 RPM. It's not the kind of thing I'd want to depend on. The issue with gyros is that the angle of the rotor is what causes the rotor to spin up faster, not the speed of the gyro. At the same time, the gyro needs to be moving at a speed fast enough for the rotor to spin up and wheels to lift off the ground. If the rotor speed is too slow compared to the gyro speed, the blades may even slow down and/or flap (it seems a vast majority of accidents happen because the pilot forgets to pull the stick back prior to accelerating). This would be a very bad day. So if you don't execute the process perfectly, you may not get off the ground in the expected ground roll. If you don't have a margin of error, another bad day. My POH say 270-400 ft. Maybe with a lot of practice I'll be comfortable with 400 ft...

A lot of the videos you see with ultra short short takeoff rolls are into high winds. You won't see them taking off from a field that's only 300 ft though.
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Roger, sounds like I would need to push the runway length to the same length I'd need in various fixed wings things I've thought about. So I'll scratch the gyro from my list of plans.
 
jesse said:
I am seriously thinking about getting some type of gyro if they can be operated in 1-200 ft of runway, which it appears they can be.

Which brands are the least likely to kill me?
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Those are more or less mutually exclusive (taking off in 1-200 feet and least likely to kill you). Kinda like with fixed-wings: there are ultralights that can take off after a short roll but then requirement 2 gets in the way.

I did several years of homework, demo flights, and even factory tours. I built a Magni in Italy and would highly recommend that company. Long list of reasons why. American Ranger is also good. Autogyro is the most popular “Eurotub” in the world but I’m not a fan, personally.

Comparing a Bensen to a Magni is like comparing a Quicksilver MX to a SportCruiser, including price. Magnis (and American Rangers and ELAs and Autogyros) are priced more like an LSA than an ultralight. You get what you pay for…
 
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MonkeyClaw said:
Ironically, I'm literally in my RV on the way to start the build on my AR-1c in Florida.
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The build quality on those is amazing. The latest video of the construction process shows superior methods of fabrication. I would buy one of those simply based on knowing how well they are designed and engineered.
 
Piperonca said:
I'm starting to get the idea any of them can kill you, and more easily than an airplane:

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THAT is why, despite having about 250 hours in gyros, I will never fly in a Bensen, which is what that looked like. Modern gyros, like the Magni, AR-1, and Autogyro, are designed specifically to make that much, much harder to do. I hesitate to say “impossible” but essentially to the point where you need to try to kill yourself that way.

There are definitely other “failure modes” for all of them (rotor management, especially for takeoff, is absolutely critical but simple) but that mode has been largely engineered out. But people still build and fly Bensen types. Much more agile than my Magni - but much more susceptible to “stupid pilot tricks”.
 
Whitney said:
Maybe someday, but not soon.
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Thanks to the good doctor, and others you now have solid recommendations. Consumer Reports for flying machines. That amphib looks like a hoot.
 
Piperonca said:
Very innovative design, it looks like. That could be where the maneuverability comes from. No pitch-over tendency, either.
https://www.buildagyrocopter.com/the-rotor-flight-dynamics-dominator-gyrocopter/
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Some of his blade efficiency explanations are just basic carryovers overs from helicopters. Although, blade twist has more to do with better distribution of lift throughout the span and better autorotational characteristics than simply “reducing drag.” Also, the author states the outboard section has increased pitch to help over come blade stall at high speeds. That’s the opposite of what you want in a rotor. The blade is flapping down, thereby increasing AoA. You want the least amount of pitch allowed so that the blade doesn’t go past critical AoA.

Other than that, sounds like a sound design. Might be my retirement toy once I can no longer maintain my medical. ;)
 
Velocity173 said:
Some of his blade efficiency explanations are just basic carryovers overs from helicopters. Although, blade twist has more to do with better distribution of lift throughout the span and better autorotational characteristics than simply “reducing drag.” Also, the author states the outboard section has increased pitch to help over come blade stall at high speeds. That’s the opposite of what you want in a rotor. The blade is flapping down, thereby increasing AoA. You want the least amount of pitch allowed so that the blade doesn’t go past critical AoA.
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I breezed past all that (forgive the pun). Studied rotor dynamics enough in my courses and it makes my eyes glaze over. Give me an algorithm and eyes light right back up. What appealed to me about the Dominator is the efficacy of control surface configuration on that machine, which is noticeably different from a lot of the others. I think what you are referencing was thrown in the article as filler without the author having a good understanding of it.
 
For anyone seriously interested in gyros, I highly recommend two things: do your homework about different models in an objective way (rather than one that tends to confirm beliefs) and commit to getting thoroughly trained.

The first part can be tough because there’s a lot of bias by manufacturers and pilots towards their gyros (as with most anything). Recognizing that risk, I still recommend the articles Greg Gremminger has posted on his website: https://magniusa.com/features.html

And, yes, I have a Magni - but it’s after seriously considering others over several years. There are other comparably safe and well-built gyros but the Magnis are a solid, reputable family who have fine-tuned their design over decades. Plus, spending a week in Milan building it in the factory and then flying it there was a big plus…
 
Llewtrah381 said:
And, yes, I have a Magni - but it’s after seriously considering others over several years. There are other comparably safe and well-built gyros but the Magnis are a solid, reputable family who have fine-tuned their design over decades.
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Thank you sir. This is the most interesting PoA thread in a while. Let me ask, do you think engine-out control of the Magni is superior to the Dominator, and if so, why?
 
Piperonca said:
Thank you sir. This is the most interesting PoA thread in a while. Let me ask, do you think engine-out control of the Magni is superior to the Dominator, and if so, why?
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Good question. A lot like for fixed-wings, engine-out per se isn’t what typically gets gyro pilots killed or even gets gyros damaged: it’s the aerodynamics. Any gyro (or FW) pilot sticking even reasonably close to their training will likely survive, depending on terrain, etc. In fact, a gyro is probably safer than a FW in many scenarios: coming down straight in "parachute mode", I understand my Magni descends at about the same speed as a Cirrus under parachute. The gyro - and I - will probably get bent but it should be survivable. And if you add in forward speed (as per our training), you can land uneventfully in many engine-out scenarios. So there's not a lot of difference between gyro models as far as engine-out survivability per se. Which is a good thing: as with ultralight FWs, smaller gyros tend to use 2-cycles and other less-reliable engines, so they get engine-outs more often than gyros or FWs with a 4-cycle Rotax, etc.

The big killer in the older style (Bensen and, I believe, the Dominator) was/is basically reversing the air flow through the rotor (so that air is effectively coming down from above rather than up from below). That can happen with “bunting” over, as seen in the video you posted Monday, in what's called a powered-push-over (PPO), which can happen in a pilot-induced oscillation (PIO). Look at the "Eurotubs" and you'll see they have the "big tail way back", as Greg Gremminger described. That makes both a PPO and a PIO much, much harder to do, especially unintentionally. The Dominator is not designed like that - the Benson definitely isn't.

In the "Eurotubs", the bigger risk is on takeoff, with "blade flap", where the advancing rotor blade (typically on the right) generates more lift than the retreating (left) one. That will roll a gyro in literally two or three rotations of the rotor. (This is true for all gyros but the "Eurotubs" have engineered out the PPO stuff, so this is more common) Again, design and training make that much less likely: in the Magni, the prerotator is a flex-shaft that allows me to prerotate in the runup area and hold the stick all the way back (which is what you need to do) for as long as I need; pretty much all the others, including American Ranger, Autogyro, ELA, etc., use a rigid system with u-joints. They need to prerotate and keep the rotor flat until the prerotator is disengaged, to avoid breaking the shafts. They typically do that on the runway, where it's easier to get distracted and not spin up fast enough and/or forget to pull back before going forward.
 
Sifossifoco said:
Wouldn't a mosquito helicopter just be better?
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I like the mosquito XE but price comparison, you could get one of the single seat open cockpit gyros for a fraction of the XE. Unless you really needed the vertical performance, then yeah, a helicopter makes more sense. Love to get a turbine XE or Eagle someday as well but a little too pricey.
 
Llewtrah381 said:
Good question. A lot like for fixed-wings, engine-out per se isn’t what typically gets gyro pilots killed or even gets gyros damaged: it’s the aerodynamics. Any gyro (or FW) pilot sticking even reasonably close to their training will likely survive, depending on terrain, etc. In fact, a gyro is probably safer than a FW in many scenarios: coming down straight in "parachute mode", I understand my Magni descends at about the same speed as a Cirrus under parachute. The gyro - and I - will probably get bent but it should be survivable. And if you add in forward speed (as per our training), you can land uneventfully in many engine-out scenarios. So there's not a lot of difference between gyro models as far as engine-out survivability per se. Which is a good thing: as with ultralight FWs, smaller gyros tend to use 2-cycles and other less-reliable engines, so they get engine-outs more often than gyros or FWs with a 4-cycle Rotax, etc.

The big killer in the older style (Bensen and, I believe, the Dominator) was/is basically reversing the air flow through the rotor (so that air is effectively coming down from above rather than up from below). That can happen with “bunting” over, as seen in the video you posted Monday, in what's called a powered-push-over (PPO), which can happen in a pilot-induced oscillation (PIO). Look at the "Eurotubs" and you'll see they have the "big tail way back", as Greg Gremminger described. That makes both a PPO and a PIO much, much harder to do, especially unintentionally. The Dominator is not designed like that - the Benson definitely isn't.

In the "Eurotubs", the bigger risk is on takeoff, with "blade flap", where the advancing rotor blade (typically on the right) generates more lift than the retreating (left) one. That will roll a gyro in literally two or three rotations of the rotor. (This is true for all gyros but the "Eurotubs" have engineered out the PPO stuff, so this is more common) Again, design and training make that much less likely: in the Magni, the prerotator is a flex-shaft that allows me to prerotate in the runup area and hold the stick all the way back (which is what you need to do) for as long as I need; pretty much all the others, including American Ranger, Autogyro, ELA, etc., use a rigid system with u-joints. They need to prerotate and keep the rotor flat until the prerotator is disengaged, to avoid breaking the shafts. They typically do that on the runway, where it's easier to get distracted and not spin up fast enough and/or forget to pull back before going forward.
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What a writeup! Several topics to unpack but landing first: I have cognitive dissonance trying to visualize a Dead Stop Landing as Gremminger describes as being exactly the same as a helicopter autorotation, or maybe I'm making it too hard. Too bad the Army isn't teaching touchdown autos any more. I don't know if PHI or any other commercial operator does either. They were great fun, but pilot technique was absolutely key. Bent metal lurked a few milliseconds away in, or within an inch or two of cyclic control displacement. However, once proficiency was attained zero ground run autos were possible with modestly favorable conditions in skid gear helicopters. It is a great "skill challenge" as Gremminger states in his excellent article, but I don't see why that couldn't be a goal for gyroplane pilots.
 
Piperonca said:
What a writeup! Several topics to unpack but landing first: I have cognitive dissonance trying to visualize a Dead Stop Landing as Gremminger describes as being exactly the same as a helicopter autorotation, or maybe I'm making it too hard. Too bad the Army isn't teaching touchdown autos any more. I don't know if PHI or any other commercial operator does either. They were great fun, but pilot technique was absolutely key. Bent metal lurked a few milliseconds away in, or within an inch or two of cyclic control displacement. However, once proficiency was attained zero ground run autos were possible with modestly favorable conditions in skid gear helicopters. It is a great "skill challenge" as Gremminger states in his excellent article, but I don't see why that couldn't be a goal for gyroplane pilots.
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I haven't read Greg's stuff in a while, so I don't recall exactly what he said about autorotation. And despite his considerable advantage over me in experience, if he said gyro and helicopter autorotations are the same, I'd disagree. A gyro is always in autorotation but it's still different because there's no collective in a gyro: unlike a helicopter, a gyro can't change the pitch of the rotor blades (at least all the ones we've been discussing; the CarterCopter can but that's a one-off and a whole different thread). So, whereas a helo could dramatically increase the pitch right before a purely vertical landing, so as to translate rotor RPM into more lift, a gyro can't. A gyro relies on forward speed to give it something to convert into lift right before touchdown (as do helos, from what I gather, but they also have the collective).

Another big difference I like with the Magnis compared with the others is their keel. If you look, only the Magni has one that's straight; all the others are bent, primarily to get the tail feathers up in the prop wash. The consequence (I'd personally say "downside") is that one can now pull back harder on the stick in the final flare for the bent-keel ones, giving a very short - even zero - ground roll. That works until it doesn't. A gust of wind or misjudging how high you are and now you're zero ground speed and zero lift. Plunk. LOTS of gyros bent that way. Some pilots try to blame "vortex ring state" for that, but that's a helicopter thing and not possible in a gyro. The bent tail tempts people to try and "hover" to a landing, which is foolish: you still need several hundred feet to take off, so all it is is risky hubris. I land my Magni with a much flatter profile and a longer ground roll but still stop within 100 feet easy - usually 30-50 - without even hitting the caster on the straight keel. Whenever I see someone with a bent keel land like they enjoy doing I instinctively cringe because I think they're about to bend the gyro - it's just so much against my training.

BTW: I was at McClellan/KMCC back in April for some training and the CalFire guys were there training as well. Aside from the water-bombers practicing their drops on the grass, their Hueys were doing full-stop autorotations. What a hoot!
 
Llewtrah381 said:
it's still different because there's no collective in a gyro: unlike a helicopter, a gyro can't change the pitch of the rotor blades (at least all the ones we've been discussing; the CarterCopter can but that's a one-off and a whole different thread). So, whereas a helo could dramatically increase the pitch right before a purely vertical landing, so as to translate rotor RPM into more lift, a gyro can't. A gyro relies on forward speed to give it something to convert into lift right before touchdown (as do helos, from what I gather, but they also have the collective).
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Please consider cognitive dissonance cleared on that characteristic, thank you. I am now appreciating there's more to these little whirlygigs than I thought.

Edit: Just remembered one time I was flying with an old National Guard IP who demonstrated a full auto to the runway in a Huey without pulling decelerating or cushioning collective pitch. It was run-on, but still. NG could get away with stuff like that in the old days.
 
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I want the gyro that 007 flew.
 
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