minimum airspeed in your gyro

[Redbaron]

was wondering how slow you could fly in your gyro under high power with the nose high? I know this is behind the power curve flight and should be done at altitude! my bee will fly at 9-10 mph slow flight! :twitch:

[RotorTom]

No, it won't.

[RotorTom]

I suspect instrument error, headwinds (you are not accounting for) or drugs (you should account for).

[WHY]

If you are flying with nose really high, then it is likely your pitot tube is not direct into the airstream or the Hal airspeed indicator is not in the correct position to read accurate thus the error

Tony

[troed@aon.at]

As ALWAYS this depends on wind conds, temp, humidity, total weight, engine hp, prop pitch etc.

You could check for YOUR gyro at satisfactory altitude (1500 ft min, better 2000 ft) at real ZERO windspeed with a good GPS. IAS-Pitot won´t show correct at nose high.

But wonder if it could be below 20 - 25 km/h ..............

[Jean Claude]

Added from tony remark. The indicator measures the pressure difference between the probe and static pressure. When the nose is high, there may be a depression in the cabin. The indication is distorted (too low with a Venturi tube, too hight with a Pitot tube)
If you have a Rotax 503 and a propeller 65 ", you can not expect less of 20 mph (30 seconds of horizontal flight)
Jean Claude

[GyroRon]

Nose high with full power and slow airspeed UNLOADS the rotor, as the engines thrust supports a sizeable chunk of the all up weight of the aircraft. The rotors slow down and you risk inflight blade flap, especially if you have either very light blade loading or very high power to weight ratio. In other words Jeff.... your either full of crap, or if your doing what you say your doing, your putting yourself in danger, EXACTLY why we all suggested at least a few hours of lessons. TO identify and understand the risks you need to avoid

[RotorTom]

In other words Jeff.... your either full of crap, or if your doing what you say your doing, your putting yourself in danger

I vote both.

[GrantR]

9 to 10 is nothing. I can make mine fly at 3 to 5mph hanging on the prop and as the rotor slows I fire up my prerotater to keeps the blades spinning.

[Passin' Thru]

9 to 10 is nothing. I can make mine fly at 3 to 5mph hanging on the prop and as the rotor slows I fire up my prerotater to keeps the blades spinning.
Good Grief!:eek:
You are just pulling our leg, ... Right? :lie:
Maybe just a lil' bit of "one-up-man-ship?:noidea:

[helipaddy]

Or roll her inverted, get the blades back up to speed, and roll her back upright

[GrantR]

With my new turbo prop engine producing 600 pounds of thrust and a max gross of 500 pounds I can hold that baby nose high in the sky. My rotax 277 powered prerotater keeps the blades spinning. It takes a ton of left rudder to keep the nose straight.:wave: :)

[Passin' Thru]

With my new turbo prop engine producing 600 pounds of thrust and a max gross of 500 pounds I can hold that baby nose high in the sky. My rotax 277 powered prerotater keeps the blades spinning. It takes a ton of left rudder to keep the nose straight.:wave: :)

OK, NOW I understand! :D:D:D

[RotorTom]

Doesn't "Red" just bring out the best in all of us?

[choppergabor]

You bunch of wussies I went out yesterday with the Behemot and without having a friggin engine or blades on the damn thing I flew if slightly nose high and measure .0000372 mp/h. Beat that!
Uhum I have to edit this out. No I did not fly it. A friend of mine did it. Hand he is asking ........

[StanFoster]

I am sitting in my Helicycle right now. 0 mph. And no engine, I kid you not! Stan

[Early Bird Dave]

And on Saturday I was hanging so long on my prop that the Earth rotated backwards and............................................... ..........:)

[GrantR]

I converted my propeller hat to a powered rotor using a big rubber band. Man I can climb at a 1000 feet a min until the band runs out. Then i auto to the ground. Who need a stinking gyro to fly. And this was with zero forward speed :)

[Dmorris]

I am sitting in my Helicycle right now. 0 mph. And no engine, I kid you not! Stan

That will get old in about two weeks!

[All_In]

Very funny guys... Good ones.

As to Stan I am sitting in my Helicycle right now. 0 mph. And no engine, I kid you not! Stan

And he's is making engine noises.... :lol:

[Passin' Thru]

And he's is making engine noises....

No, he has the shopVac running, tied under the tail boom! :lol:

[Resasi]

Oh no he left the hose loose it swung round and attacked the pitot tube...hang on a sec he's going -80 kts!!!!!!!! Wow.

[StanFoster]

Ok.....You guys guessed pretty close. I have decided to go with a DeWalt motor.....turns 30,000 instead of 62,000 but at least I have a motor. I just will have to add more pitch to the slower turning rotor......


YouTube - DeWalt powered Helicycle (http://www.youtube.com/watch?v=L9VLlrlopoo)


Stan

[choppergabor]

ROFL good one Stan :) A motor is a motor..... And that's all I have to say about that (Forrest Gump)

[ultracruiser41]

Stan,

Glad you're going green and turning in that fuel hog turbine for an electric hybrid!

As for the minimum airspeed in the original post........I'll donate for flowers.


Barry (told ya so) K

[Earthboundmisft]

Stan, you aint right man!!!:der:

[All_In]

Stan, you aint right man!!!:der:
I know that is why I hang out with him. He makes me look almost normal.....

[Fl90]

My Bensen with the 503 and 23'ers would back down the runway in a 15mph wind.

Hope you are well.

Phil

[birdy]

The rotors slow down and you risk inflight blade flap,
Wot makes you think that Ron?
The blades slow coz the weight hangn off them is less [ lower AOA]. Theres no reason why theyd flap.
The airspeed difference between advancing and retreating blade is minimal, so teeter is also. No reason for blade flap.

The main things to watch for at min AS at WOT is torque roll and sink. Things can turn to sh1t real quick wen you start sinkn at WOT and nose high, like reversed airflow. Wen this happens, the machine can change attitude or rotate or both, real fast, and the slow RRpm means the blades may not be able to keep up, and youll get serious cyclic flappn.

BTW, the ferel will sit there all day at 0 IAS.
[ bout 15 actual]

[GyroRon]

Birdy if you get the blades too slow, they loose their stiffness and you can flap them

[MichaelBurton]

I agree that the blades will slow a little at slow airspeed. We do not have an elevator so we can not hang on the prop like a fixed wing. Unless the attitude is attained by a high speed steep climb or some other unusual maneuver things will stabilize and the rotor rpm will not slow to the point of losing the ability to support the gyro.

With a stable gyro you will enter a high descent rate and slow airspeed configuration when you lift the nose past the minimum steady flight speed.

The blades slow due to the fact that they are not generating as much lift. But once the descent rate stabilizes the rotor rpm decay will abate. The recovery is simple let the nose down and gain air speed. The high descent rate and slow airspeed maneuver is part of the PTS in the US. The book specifies that the power setting be less than cruse power for the test. I have tried it with higher power settings and monitored the RRPM I have never seen anything close to excessively low rotor speeds.

I believe that The flap that Ron is referring to occurs when the load is removed from the rotor. A steep climb followed by a push over at the top would do it. Not a recommended maneuver and possibly deadly. If you do remove the load from the rotor they will not stay in plane and may chop any part of the gyro. I don't believe the rotor will have time to fold prior to making hash out of the aircraft but have not tried it or seen it tried.

Take care

[MichaelBurton]

YouTube - 3D Animation of a Robinson R44 Helicopter in a Negative G tail boom strike. (http://www.youtube.com/watch?v=R3a4ytlKsoA)
Here is a video of what might happen in a low g pushover.

[MichaelBurton]

Or like this
YouTube - HILLER FH-1100 CRASH DURING A DISPLAY (http://www.youtube.com/watch?v=7P3zYDgnYew)

Here is a link that explains the problem better than I care to. Low G (http://blog.aopa.org/helicopter/?p=267)

[GyroRon]

Micheal, what I am describing may not be possible in the types of gyros you fly in, or most gyros.... But in my own gyro with the long rotors and the amount of thrust my engine produces, it is very easy to slow the rotors to a rpm lower than the lowest rpms shown at lift off. I have avoided allowing them to go any slower as I was warned by the manufactor of the blades that at this slow of a speed they loose their stiffness and can flap or even buckle.... bad things would happen in other words.

But what your saying is no matter how powerful your engine, nor how light your blade loading is, you can pull back stick and slow to zero airspeed at full power and there are no issues to be concerned about?

[Graeme Monro]

Birdy if you get the blades too slow, they loose their stiffness and you can flap them

Birdy never looses his "stiffness",
he always has one hand on it at all times.

Graeme.

[MichaelBurton]

Micheal, what I am describing may not be possible in the types of gyros you fly in, or most gyros.... But in my own gyro with the long rotors and the amount of thrust my engine produces, it is very easy to slow the rotors to a rpm lower than the lowest rpms shown at lift off. I have avoided allowing them to go any slower as I was warned by the manufactor of the blades that at this slow of a speed they loose their stiffness and can flap or even buckle.... bad things would happen in other words.

But what your saying is no matter how powerful your engine, nor how light your blade loading is, you can pull back stick and slow to zero airspeed at full power and there are no issues to be concerned about?

If you are flying close to the low blade speed limit in your gyro then I would worry about the blades in all flight attitudes. If you are close to this low speed limit It may be wise to decrease the rotor size.

The nose of the gyro can not be held up with out some force. Unless you have a LTL gyro or a controllable elevator you will be unable to maintain an attitude that allows the engine thrust to take much of the load.

Ron what RRPM did the manufacture set as the low speed limit? I have practiced high power low speed flight in the SH the RRPM drops only about 30 RRPM below normal flight RRPM and is well within RRPM limits. I did this yesterday just to get the numbers. I had full power IAS of 0 and RRPM -30 from level flight. The only issue is that the gyro wants to spin to the left.

[GrantR]

Ron's gyro is LTL

[All_In]

When flying at extremely low speeds, is this picture an effective method to avoid blade flapping? :noidea:


For more information on Ron's new technique see: http://www.rotaryforum.com/forum/showthread.php?t=20688

[MichaelBurton]

Ron's gyro is LTL

Then he may be able to cause an excessive low blade RPM and should take extra care in this area.

[MichaelBurton]

When flying at extremely low speeds, is this picture an effective method to avoid blade flapping? :noidea:


For more information on Ron's new technique see: http://www.rotaryforum.com/forum/showthread.php?t=20688

I have no experience in this area and would need to have Ron demonstrate this new technique for me. It does not look to dangerous. Is there a sound track for this?

[All_In]

... Is there a sound track for this?
I think Ron had to buy the sound track from a blackmailer and destroyed it.... something about incrimination or evidence IIRC. :noidea:

[PalmPilot]

Here's a good educational video on understanding Mast bumping, flapping & Low G's... Apparently where the phrase " Treat the cause & not the symptom" came from...
Note: long video...YouTube - Mast Bumping - Causes and Prevention (http://www.youtube.com/watch?v=_QkOpH2e6tM)

Mike

[GrantR]

How was a 20 min video uploaded to youtube? I though 10min was the limit.

[MichaelBurton]

I am glad you warned me that it was long so that I could bring lunch and a pillow.

[All_In]

@Mike
I learned from that, thanks!!!

[Resasi]

Good video, thank you.

[SideKick]

It also broadened my understanding, thanks

[GyroRon]

I was told to never allow the blades to go slower than what they turn at the point of lift off. With the old engine the gyro would lift off at 260-270 RRPM, and I could easily get the rotors to 270 in flight by holding the airspeed at or close to zero and at high power setting. The gyro now lifts off about 275-285 rpms and I have again seen 270 in flight with only about half throttle and zero airspeed. I am afraid to see how slow I can possibly get them to.....

[birdy]

Birdy if you get the blades too slow, they loose their stiffness and you can flap them
Then flapn is the rong term Ron.
Fold would be more accurate.
but i dout that would be possable.

But in my own gyro with the long rotors and the amount of thrust my engine produces, it is very easy to slow the rotors to a rpm lower than the lowest rpms shown at lift off. I have avoided allowing them to go any slower as I was warned by the manufactor of the blades that at this slow of a speed they loose their stiffness and can flap or even buckle.... bad things would happen in other words.
A rosco witha a 912 is hardly a slug Ron, and iv spent hundreds of hours at full tap, just before sink, and iv never floded or buckeled a blade yet.
Like i said, it aint possable.
Wot is possable is over stressn the hub bar through too high a cyclic rate for the low rrpm if the machine pitches too fast.
Besides, CB says that a rotor can regain flyn rpm from as low as 50% normal rpm without too much hassle. Thats alot slower than the regular "horse it off" rrpm.

But what your saying is no matter how powerful your engine, nor how light your blade loading is, you can pull back stick and slow to zero airspeed at full power and there are no issues to be concerned about?
Been do'n just that for years Ron, And hold it at WOT, sinkn steady, almost to the ground and never hada problem.

Everythns relevant Ron.
High loaded rotors will have high flight rrpms, high min rrpms, and high min lift off rrpms.
low loaded rotors hare the same.
Its the percentage of veriation that counts.
If the blades a set to fly XX machine at XX load, they gouvern the rpms that suit the variants.

I dont have the advantage of a rotor tac, so i cant give numbers, but a regular move the ferel goes through many times a day is,
top off from a virtical climb, level the disc [ horisontal] , apply full power and go strate into a full power virtical sink. Itd start loosen rrpm at the bottom of the climb, loose more at the top, more from the rapid, high cyclic at the top, and more still till the decent start to steady. mite b e a good thing i dont hava taco, coz id probably never do it again.
Yes, they are ' mushy' till the rrpm catches up, but iv never floded/flaped once.

[Fl90]

there's mushy.....and then there's MUSHY. I just got a machine with a rotor tach, and a bunch of other dials. I'm thinking of taping over them to keep my blood pressure down!

Phil

p.s. maybe a bigger rudder too.

[C. Beaty]

Whether or not a rotor will flap catastrophically depends upon airspeed and the angle of flow through the rotor disc.

During rotor startup, flapping would be eliminated if the rotor disc could be tilted back 90º so that edgewise flow was eliminated. It would either start or slow down.

[MichaelBurton]

Whether or not a rotor will flap catastrophically depends upon airspeed and the angle of flow through the rotor disc.

During rotor startup, flapping would be eliminated if the rotor disc could be tilted back 90º so that edgewise flow was eliminated. It would either start or slow down.

I guess I don't quite understand what you are saying.

Please explain

[getut]

Sounds like he's saying that if ground and tail behind the gyro weren't the limiting factor and you could rotate the blades back all the way (think drag chute or a gyro in a vertical descent) where the advancing air was hitting the bottom of disk straight on rather than mostly edge on like a normal takeoff.

[C. Beaty]

I guess I don't quite understand what you are saying.

Please explainA rotor will recover from lower rpm in a vertical descent than with translational airspeed.

[MichaelBurton]

A rotor will recover from lower rpm in a vertical descent than with translational airspeed.

I understood that and have seen it many times.

What I was having problems with was that 90 deg. Statement but now I think I understand. If the disk were tipped back far enough it would be the same as a vertical descent and there would be little or no flapping required as there would be no difference in the air velocity over the airfoil induced by the movement of the gyro. That is intuitive to me but I did not see how it would be applied to the situation of a low G flapping / mast bump event. Thanks for the graphic.

[Redbaron]

sorry for not respondin, had a stomach virus for a few days and felt like crap. the airspeed specs on my bee aren't much off from ralph taggarts original bee! this isn't voodoo lol my disk loading is light! ron your welcome to come over anytime, pm me when your free. it will fly slow under power maybe It was 10-12 mph hell I don't know its pretty neat to go that slow tho! got some rotor shake above 35mph, need to clean those bugs off. ;) she doesn't like to go real fast thats for sure :wacko:

[Redbaron]

I only went that slow under dead calm conditions! fly fast in strong thermals then you might see your rotor tach dance! :smokin:

there's mushy.....and then there's MUSHY. I just got a machine with a rotor tach, and a bunch of other dials. I'm thinking of taping over them to keep my blood pressure down!

Phil

p.s. maybe a bigger rudder too.

[RotorTom]

Is it me? Or does he just not make any sense?

[Fl90]

Just doesn't have a solid understanding of the gyro.

Best thing to do is keep him in discussions and feed him info as politely as possible. He is already flying, and this is a good source of information for him. We just need to keep him reading till it sinks in.

I hope I don't have to contribute to the flower fund.

Phil.

[Redbaron]

sounds like you need some more brain food, I have a good understanding! you have been brainwashed by those " unstable gyros" that they are super unstable and dangerous lol

Just doesn't have a solid understanding of the gyro.

Best thing to do is keep him in discussions and feed him info as politely as possible. He is already flying, and this is a good source of information for him. We just need to keep him reading till it sinks in.

I hope I don't have to contribute to the flower fund.

Phil.

[Fl90]

That's just it. Gyros aren't dangerous, as long as you know what's going on.

Your statements lead to the contrary, leaving them peculiar and the readers scratching their heads.

For instance....."I only went that slow under dead calm conditions! fly fast in strong thermals then you might see your rotor tach dance!"

One has nothing to do with the other, and the slow rotor rpm discussed earlier has nothing to do with thermals. Unloading of the rotor was acomplished with the propeller thrust and nose over.

All accidents are not in turbulent weather.

Phil

[brett s]

I don't understand why people keep feeding the troll.

[StanFoster]

Brett- EXACTLY.

[GrantR]

Jeff,

Since your the expert on gyroplane theory, Why don't you write a book on it?

I think Phil might just know a little more about gyros than you.

One of my favorite signatures on here is "Ignorance is curable, Arrogance is Terminal"

[RotorTom]

The more I read his threads the more I am convinced he is a TROLL. No one can be that thick-headed and ignorant especially after numerous attempts to reason with him. He defines why the sport suffers with a questionable reputation.

[StanFoster]

Jeff had most of us eating out of his hand just months ago....until his true colors came out. I have never seen such a change in attitude from a person....as well as towards this person. Credibility is easy to obtain....easy to lose....and very hard to get back.


Stan

[GrantR]

Very easy to lose creditability when you become an expert in gyroplane aerodynamics and scotch tape an air bubble level to the keel to determine if the gyro is stable:puke:

[Fl90]

I've met him and found him quite pleasant. His posts may be out of spite, for reasons unknown to me. He may have a good understanding of what's going on and post the contrary for a reaction. One can hope.

Phil.

[Passin' Thru]

Jeff had most of us eating out of his hand just months ago....until his true colors came out. I have never seen such a change in attitude from a person....as well as towards this person. Credibility is easy to obtain....easy to lose....and very hard to get back.


Stan

Stan (& Phil), He seemed to be a pretty good kid until he went back to using mind altering substances!
I've seen it happen more times than once! :sad:

[Lspav8r]

Is any of this arguing getting anyone anywhere?

[Fl90]

Arguing?

missed that part

[Resasi]

Nope, no arguing.

Just wondered why the thread got bumped up though.

[StanFoster]

Jim- For not caring, why did you dredge this thread out and bump it today? It was refreshing to see the sleeping dog lay, now you kicked it to life. It will go back to sleep if you don't kick it again. Stan

[Dale Young]

I dunno where all of this is going, But I can fly my bee nose-high in slow flight under 20mph, and I do it regularly. Almost the speed of a brisk walk.

[TERRY LEE]

Ok, I have never even flown a gyro yet, and i'm just trying to make heads or tails of this. I am a helicopter mech, so I understand most of what you are talking about. But, a gyro is not a helicopter as all you guys know. So, from a rookie point of view, if a guy goes way nose high, isn't he going to stall the retreating blade? I'm just trying to understand because I don't know any different. Thanks

[BEN S]

you should probably ask this on a new thread, this one has outlived its usefulness.
Ben S

[bmoore2156]

Terry,
You will get retreating blade stall from going too fast, just like in a helicopter.
When you go nose high in a gyro you will climb and or slow down, depending on your engine power setting and how quickly you pull the nose up.
If you keep bringing the nose up until you reach 0 airspeed, you will go into a vertical desent. In a fixed wing, they call this a stall. In a gyro, it's not really a stall, because you have complete control of the gyro throughout the manuver.
If you do this with a high power setting, your prop will actually "lift" some of the weight off your rotor. Your weight hanging from the rotor is what keeps it spinning at flight RPM. By removing some of that weight, they will slow down. If your blade loading is low, then they could slow down enough to flap. You would want to talk with the manufacture of the rotor you end up with about minimum rotor rpm, and make sure you stay above it.
The short answer to your question is no, you can't get retreating blade stall from flying to slow.
Brad

[willisbr]

Great paraphrase Brad!

[Redbaron]

not all fixed winged aircraft stall in a conventional manner! my skypup only mushed and sank mainly because of the limited elevator travel and rudder only control. spin proof too, its hard to spin if you can't stall one side of the wing!

Terry,
You will get retreating blade stall from going too fast, just like in a helicopter.
When you go nose high in a gyro you will climb and or slow down, depending on your engine power setting and how quickly you pull the nose up.
If you keep bringing the nose up until you reach 0 airspeed, you will go into a vertical desent. In a fixed wing, they call this a stall. In a gyro, it's not really a stall, because you have complete control of the gyro throughout the manuver.
If you do this with a high power setting, your prop will actually "lift" some of the weight off your rotor. Your weight hanging from the rotor is what keeps it spinning at flight RPM. By removing some of that weight, they will slow down. If your blade loading is low, then they could slow down enough to flap. You would want to talk with the manufacture of the rotor you end up with about minimum rotor rpm, and make sure you stay above it.
The short answer to your question is no, you can't get retreating blade stall from flying to slow.
Brad