Negative Gs?

Aviomania

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Abid.. so you say that in the video you do not see the torque over and his full left cyclic input to compensate?

even an HS if it was not in the propwash was not going to save him.

any way... when you are ready for the challenge let me know.
 

phantom

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I feel quite comfortable in saying the same thing about aviomania gyros as I say about dominators , They won't kill you, you can do something stupid and kill the gyro and take yourself out in the process but the machine has no hidden bad habits that will bite you.
Norm
 

Vance

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My answer to a relevant question.

My answer to a relevant question.

1. how does the low g happen? If it is not the pilot deliberately flying a parabola then it must be an atmospheric gust.
.
A Ragu quote from the old thread titled Gyroplane Stability and Aerodynamics - Glasgow University.

I feel that his question is relevant to this thread and what it has become.

My answer to Ragu’s question is; a third option is a low g event often happens because the pilot made a mistake. I feel this is important to understand when designing an aircraft.

My mistakes have not been deliberate. I have no doubts I will make more mistakes.

I doubt if the pilot in the WAG mishap intentionally unloaded the rotor and he had probably been taught it was a bad thing to do.

I feel there is value in an aircraft that is forgiving of pilot errors; the more forgiving the better.

I would not get value out of studying NTSB accident reports if the first thing I did was declare I would never do anything that stupid because I know how to fly. I feel the value comes from understanding that a functional pilot found a path to a mistake that was part of an NTSB accident chain and I work to mitigate that pilot tendency to build a similar accident chain.
 

fara

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Abid.. so you say that in the video you do not see the torque over and his full left cyclic input to compensate?

even an HS if it was not in the propwash was not going to save him.

any way... when you are ready for the challenge let me know.
Nick, my friend. Prop wash is not the strongest at the center of the prop specially in something like your gyroplane. Why do you think that? Oh and what is your plan if the engine quits and low G event happens then. No prop wash, your HS being so close to engine. How effective is that. I am not saying its ineffective but it certainly is not going to be as effective if it was a bit lower and a bit farther back so air had a chance to meet and provide more effective response.

I saw the torque over, yes. It was way too late. It took almost 2.5+ second in unloaded condition for him to torque over. If you think he had any chance of surviving after leaving himself in sustained 2.5 second unloaded rotor event, then he also had plenty of time to cut the power. But IMO he was done by then anyway. If at 14 second he had banked left and established loading again, he had a good chance to cut the sequence of events. He was already over and almost vertical (not completely though) facing the ground before it started to happen. He should have at least kept some airspeed going. The blades were flapping like crazy if he did not torque over, he was about to get something chopped next. There wasn't just one thing wrong there starting with trying to show off to letting airspeed decay and staying in low/zero G for at least 2.5+ seconds to letting nose over happen much to not having any pitch dampening device to not cutting power, not banking when the chance was there. These things should not be done till you have timed them all out and have experience. The problem with gyroplanes is that they are maneuverable and their movement of control is way less than any airplane or trike that any normal pilot would be flying. I have said before a larger amplitude of movement may help in gyroplanes but you will give up something to get something.

Nick: I am not one claiming anything like this. You are. You ought to prove your claims. What am I proving? The thing I am not claiming? That makes no sense. I will completely tell people, you should stay away from flying that parabola.
If someone is really scared and says I can't stay away from that. I'd rather install them a BRS and tell them fly at 500+ feet AGL till they get experience and confidence.

https://www.youtube.com/watch?v=VJ0eQGr-35Y
 
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fara

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...
I doubt if the pilot in the WAG mishap intentionally unloaded the rotor and he had probably been taught it was a bad thing to do.
...
Vance and how do you know that? He was a high time pilot in other category of aircraft. I would say when things start to go haywire, chop the power and smoothly pull the cyclic back if anything
 
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birdy

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You don’t invest in blue ribbon bulls unless they can make money for you and show a decent return on your investment

No CB, the best bulls are the ones bred here, for these conditions.
I know i can bring home a 10K bull that isnt up to the standard of wot grows ere.
Like machinery, you by the best available, then improve it.
Coz only the owner knows wot he needs, he,s never go,n to get a new one off the shelf thatll suit.
I only by one lead bull every 3-4 years, for fresh genetics, and breed 100 a year for my replacements. ;)
 

Vance

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What is you point Abid?

What is you point Abid?

Vance and how do you know that? He was a high time pilot in other category of aircraft. I would say when things start to go haywire, chop the power and smoothly pull the cyclic back if anything
In my parlance doubt is not the same thing as “know” Abid.

I suspect very early in his training he would be told to avoid low g in a gyroplane with a two blade semi rigid rotor.

I was taught to avoid low g events before my first flight in a gyroplane.

I advise avoiding low g events and explain why before a student’s first flight.

If he was intentionally trying to unload the rotor it was still a mistake.

He probably did not intend to die on that flight.

I wasn't there and I don't know what the pilot was thinking so I don't know what action would have been the best.

In my opinion if someone is making a zoom climb "smoothly pull the cyclic back" may not be the best advice even after reducing the throttle.

Pulling the cyclic smoothly back is how I initiate a zoom climb. Pulling it back further might exacerbate the situation. I feel each situation is different, each pilot has different skills and each gyroplane reacts in different ways to cyclic inputs.

Based on my motorcycle road racing experience; when I am in a race reducing power is not my first reaction to anything.

I have not raced a gyroplane so I don't know how I would react to the situation that triggered the accident sequence.
 

C. Beaty

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You don’t invest in blue ribbon bulls unless they can make money for you and show a decent return on your investment

No CB, the best bulls are the ones bred here, for these conditions.
I know i can bring home a 10K bull that isnt up to the standard of wot grows ere.
Like machinery, you by the best available, then improve it.
Coz only the owner knows wot he needs, he,s never go,n to get a new one off the shelf thatll suit.
I only by one lead bull every 3-4 years, for fresh genetics, and breed 100 a year for my replacements. ;)
I realize you know what you need in bulls because it’s your business.

Gyros, however are sold to the general public on the basis of prettiness; fancy upholstery, custom molded knobs and Spaceman Spiff wheel spats.
 

Murray Barker

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Birdy,flogging a dead horse.

This thread just reinterates to me that people who build and sell gyro's to the unsuspecting public should have more than just a basic understanding of how they work.
 

Gyro_Kai

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Here is the reminder but you have to read it through completely from this page onwards, all the way. He takes you through why gyroplanes with good H-stabs resist getting into sustained zero or very low G loading. Would be good for Kai also.
When it does not last in very low G loading before re-loading, there is then no torque over. The counter to that is if the pilot keeps it there and sustain the very low G by his actions and also keeps high power setting on then its over for the pilot unfortunately.
So, an H-stab prevents torque over? And there is a time limit, how long a low-G must be maintained to start a catastrophe?

I'm officially out of this thread. It just ain't worth it.

Kai.
 

fara

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"Here is the reminder"
You are jokeing, rite?
Absolutely not. Just because he wanted you speciifically and calmly to think through something doesn't mean he did not answer your questions. His answers to you were clear
 

cessna.682

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"our enclosed models are the same as our open frame with slightly larger tail to cope with extra area of the cabin. we kept the cabin as small as possible to fit a 6'3" 210 lbs pilot ( actually a 6'6" 230 lbs went in also). i could make it bigger... but it is safer to keep that size. Little bigger can also be safe but not as the size we chose. and yes they are also CLT and have an active torque compensation tail."

Nicolas, could you incorporate your design features into a semi-enclosed Aviomania gyro like the euro models that are very popular? Seems like a market opportunity.
 

fara

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So, an H-stab prevents torque over? And there is a time limit, how long a low-G must be maintained to start a catastrophe?

I'm officially out of this thread. It just ain't worth it.

Kai.
Kai
That's your choice but torque over happens late in the game where a low G event has been sustained. There are two ways to get to that point.
1) no HS or dampening that allows unloading to continue
2) pilot action

You can even carefully see that a Bensen gyro Florida wn in Japan what had the torque roll happen, how long it sustained low G and what was its attitude before it happened.
Second torque roll happens because there is a high power setting. When one starts to lower power at the instant one feels reduction of loading and increases the loading by banking or with increasing disc aoa it can be avoided. This should be taught. It should work with any stable Gyroplane.
In any case for have never said that torque roll is not present it HS prevents torque roll. Not sure where you are getting that. Raghu's proposition was that HS gives you the ability to avoid getting to situations which create the circumstances where it can happen but if the pilot decides to do u advisable show off maneuvers then it's necessary pilot has experience and understands their machine well including recovery from unusual attitudes. The WAG pilot did not at 70 hours of Gyroplane experience.

I have said also that there are multiple ways of avoiding torque roll and a crucifix tail with differential incidence HS halves in the center of the prop is not the only way. Chuck Beaty prefers this solution and cited Cierva's patent in his own defense. The problem is Cierva's listed at least 5 different ways in that very patent to balance torque rolling moment of which Chuck's preferred way only one. Cierva's patent in fact makes the point for me. If you think this is wrong: you have not been reading.
 

thomasant

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Fara, you seem to have all the answers.

But you still have not explained what to do in a stuck WOT malfunction in a transient low G situation, where the machine begins to get into torque roll.

IMHO, perhaps the time you spend arguing on this thread, you could instead spend the time re-designing a machine that will be a three in one solution for power/pitch /roll and yaw coupling. (Hint: I believe it has been done 80 years ago, as brought out before by CB, and Aviomania seems to be on the right lines).
 
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fara

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Birdy,flogging a dead horse.

This thread just reinterates to me that people who build and sell gyro's to the unsuspecting public should have more than just a basic understanding of how they work.
Wow Murray:
So how many engineering degrees do you hold my friend?
:).

When you don't get a concept, try not to just push the messenger. Raghu in that thread did a pretty thorough job about showing this forum why gyroplanes like Magni and MTO are pitch stable step by painful step and why they left try and avoid sustained unloaded conditions and start reloading in as little as 0.045 seconds unless pilot actions state otherwise.

I don't know when the last time Chuck Beaty flew an MTO or Magni or AG1 or anything like that. I don't know if he even ever got his pilot's license (probably not) so I am not sure he can legally even do some testing on any of these but I think its time he starts coming up with a criteria he wants met and then test some of these machines before talking too much.
It is becoming the case of partial solutions being portrayed as the magic bullet without even proven testing and without even a criteria.
 

fara

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Fara, you seem to have all the answers.

But you still have not explained what to do in a stuck WOT malfunction in a transient low G situation, where the machine begins to get into torque roll.

IMHO, perhaps the time you spend arguing on this thread, you could instead spend the time re-designing a machine that will be a three in one solution for power/pitch /roll and yaw coupling. (Hint: I believe it has been done 80 years ago, as brought out before by CB, and Aviomania seems to be on the right lines).
Shutdown the engine :). Takes 0.25 seconds

Thomas with all due respect, if you think the links I have pointed to which are from Glasgow, Juka, Prof. Laine, Raghu which contain studies from UK in 2011 to studies from germany to Raghu's own analysis to statistical data of gyroplanes with effective H stabs being flown by 10's of thousands of hours much more safely than anything in the US over 1000 hour of flight activity, if you don't think Roy Davis' analysis that that accident was not machine's fault is correct, then its your choice to buy a gyroplane claimed to automagically recover from low/zero G events like ones happened at WAG doing the same pilot actions with almost no loss of altitude but no proof of such provided not even a test script. Last video Nick posted had nothing in it we can't do although in the verbal discourse at first he made it sound very exotic. He is a good pilot.
 
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thomasant

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Fara,

Unfortunately, not the answer that I was looking for. But it is an answer. Most pilots will not react that fast or have the presence of mind to shut the engine off when they are in trouble and in the process of getting inverted.

Raghu's explanations are mainly for the effects of the HS in the pitch axis ( I remember the thread well). Torque roll is in the roll axis and not discussed in that thread.

I would not be able to switch the engine off in .25 seconds in a stuck throttle situation in a transient low G situation.

If I were looking to invest in a new gyro, all things else being equal, I'd look for one with torque roll protection.
 

fara

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Fara,

Unfortunately, not the answer that I was looking for. But it is an answer. Most pilots will not react that fast or have the presence of mind to shut the engine off when they are in trouble and in the process of getting inverted.

Raghu's explanations are mainly for the effects of the HS in the pitch axis ( I remember the thread well). Torque roll is in the roll axis and not discussed in that thread.

I would not be able to switch the engine off in .25 seconds in a stuck throttle situation in a transient low G situation.

If I were looking to invest in a new gyro, all things else being equal, I'd look for one with torque roll protection.

Well this thread is titled negative G's. Negative G has to be sustained to get to the point where rollover will happen. Don't sustain it. Pitch stability helps you out there but you have to let it. If you do "Not" cut the power and do a maneuver like bank (even 20 degrees to the left) or pull the cyclic back then yes you will get to the point of no return. That takes multi seconds. You have to like the WAG pilot push the cyclic forward and keep it that way. You are welcome to count the seconds very carefully in Nick's accident. I was able to count 2.5 seconds before torque roll happened. That is sustained low G and that was a Bensen that had no HS

I am simplifying it for you. In the event of feeling light in your seat, cut power, smoothly pull cyclic back a bit and preferably also bank left 20 to 30 degrees till full seat of the pants feel is restored. This has to be drilled in and it needs to be muscle memory and internalized.

You can go for the Aviomania. It follows a prescriptive method from Chuck Beaty. I have told Chuck there are other methods of torque roll compensation but he is stuck on his ego box and keeps throwing jabs at me. He posted Cierva's patent. Guess what Cierva agrees with me in that patent. He listed multiple ways of getting torque roll out. Actually I am surprised he was awarded that patent because some of the techniques he listed were in use by some airplanes already.
I believe fixed differential incidence over full half stabs has its own moments and a better approach is possible
 
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thomasant

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Well this thread is titled negative G's. Negative G has to be sustained to get to the point where rollover will happen. Don't sustain it. Pitch stability helps you out there but you have to let it. If you do "Not" cut the power and do a maneuver like bank (even 20 degrees to the left) or pull the cyclic back then yes you will get to the point of no return. That takes multi seconds. You have to like the WAG pilot push the cyclic forward and keep it that way. You are welcome to count the seconds very carefully in Nick's accident. I was able to count 2.5 seconds before torque roll happened. That is sustained low G and that was a Bensen that had no HS

I am simplifying it for you. In the event of feeling light in your seat, cut power, smoothly pull cyclic back a bit and preferably also bank left 20 to 30 degrees till full seat of the pants feel is restored. This has to be drilled in and it needs to be muscle memory and internalized.

You can go for the Aviomania. It follows a prescriptive method from Chuck Beaty. I have told Chuck there are other methods of torque roll compensation but he is stuck on his ego box and keeps throwing jabs at me. He posted Cierva's patent. Guess what Cierva agrees with me in that patent. He listed multiple ways of getting torque roll out. Actually I am surprised he was awarded that patent because some of the techniques he listed were in use by some airplanes already.
I'm posting an excerpt from the summary posted by Raghu in the thread referenced. It is the essence, and seems to be eluding you.

"11. It is important to do what ever to stay away from low g conditions. Irrespective of stability characteristics all teetering rotor gyros need to stay away from sustained low g conditions. Any more than a fraction of a second of neg G can be very detrimental."

If I inadvertently get into a situation of low G, all that it takes is a fraction of a second for getting into a bad situation. If I'm at WOT and experience a downdraft, my reaction is to reduce power first, which itself takes a couple of seconds. ( I do have the helicopter hours for this action to be drilled into me). So I have already lost a couple of seconds, and I realize that I am starting to get inverted. It then sinks home that my throttle is stuck. I'm inverted by now. I do not need to go on with the sequence of events....

How hard is it to include this feature in the manufacturing process for a machine that prevents this "roll over"?

IMHO, I just find it mind boggling that you as a manufacturer are trying to sabotage your own business.
 
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