Gyro's vs Helicopters

[whirly]

Thanks FLYNOTE!! Mind is made up!!

Next I need you or anybody else to explain an engine out in a gyro to me please! Does a gyro have a height vs speed diagram like a helicopter, or is it much safer ? Do you recover with power or do you do fly it all the way to the ground in autorotation excercises? In the SAAF we did autorotations all the way to the ground with no option to use the engine but nearly all civilians schools will never do that, and rightly so,why create a real emergency when it's not necessary?

I have never seen a gyro do one.

Whirly.

[Yoda]

Whirley... is it Whirly from Avcom??
Funny because I'm in the same boat as you, but I'm looking to start flying helikopters. Already did 5 hrs in a Robish 22. Man those helis are unstable if one is used to a gyro.
To answer your question regarding Autorations....

In a Gyro all landins are basically "enjine off"
Landing a gyro goes like this: Get your descent angle and trim your airspeed to 65 mph. Keep speed 65. If you are to fast, decrease power, and the other way around if you are too slow. On finals you controll the speed with the forward throttle and not the cyclic.
Then you execute a "flare" with the cyclic just before you hit the ground and land. Thats all there is to it. You can switch of your enjine if you want and still do a perfect landing with basically little forward groundspeed on touchdown .. depending on the wind. Thats whats so nice. If you loose your enjine, nothing changes as far as you rotor rpm goes. You just need to find a spot and put her down safely.
Only thing that needs to be kept in mind is you airspeed. But then if you are high enough you can even pul her up to 0 airspeed, then drop the nose again to excecute a landing.
Hope this helps. Maybe the other guys can fill in but thats basically it.
I also might ad that if you were to practise a complete enjine out, it will be on the runway, othewise you wont be able to take off again and you might end up putting a few dents in the Magni...
Also, I think you will be able to fly the gyro in a jiff with all your flingwing experience....

[whirly]

Whirley... is it Whirly from Avcom??
Funny because I'm in the same boat as you, but I'm looking to start flying helikopters. Already did 5 hrs in a Robish 22. Man those helis are unstable if one is used to a gyro.
To answer your question regarding Autorations....

In a Gyro all landins are basically "enjine off"
Landing a gyro goes like this: Get your descent angle and trim your airspeed to 65 mph. Keep speed 65. If you are to fast, decrease power, and the other way around if you are too slow. On finals you controll the speed with the forward throttle and not the cyclic.
Then you execute a "flare" with the cyclic just before you hit the ground and land. Thats all there is to it. You can switch of your enjine if you want and still do a perfect landing with basically little forward groundspeed on touchdown .. depending on the wind. Thats whats so nice. If you loose your enjine, nothing changes as far as you rotor rpm goes. You just need to find a spot and put her down safely.
Only thing that needs to be kept in mind is you airspeed. But then if you are high enough you can even pul her up to 0 airspeed, then drop the nose again to excecute a landing.
Hope this helps. Maybe the other guys can fill in but thats basically it.
I also might ad that if you were to practise a complete enjine out, it will be on the runway, othewise you wont be able to take off again and you might end up putting a few dents in the Magni...
Also, I think you will be able to fly the gyro in a jiff with all your flingwing experience....

Yoda,

Yebo, the same SOB!! Could not dare to use another name and password, won't remember them!!

I was thinking that lots of helo time might be dangerous when converting to a gyro,not??

Yes, I know most landing are "engine off" ones and so is the flying, but what happens when your "other" engine fails?? I know you can flare but you don't have a collective to cushion your landing, seems to me you need absolute perfect timing!

Stay away from the Robbish, it's unstability is the best of it's characteristics!

Whirly.

[t-bird]

Hi Yoda

Height is throttle – too low add power – too high cut it
Airspeed is stick

Same as 3-axis

[FO Gyro]

Hi Whirly,

A gyro definitely does have a height/velocity graph, but it is much more forgiving than a helicopter, and would could therefore say more safer than a helicopter when flying low and slow.

The first graph is for the average two seater gyro. In the 2nd graph, from a Bell 204 helicopter, I have shaded in blue where a gyro's height/velocity graph would fit in. As you can see, a gyro can fly much lower, and slower than a helicopter.

Whirly, just like a 3 axis fixed wing, a gyro can fly a power on or power off/glide approach. Unlike in a helicopter, the flare height is not critical at all, and is very similar to landing a fixed wing, except the gyro comes to a stop extremely quickly. You can approach the runway from directly overhead the threshold, or you can fly the flatist approach, that's the beauty of flying a gyro, they are so versatile.

Gyro & Bell 204B Height Velocity Graph.jpg (57.17 KiB) Viewed 4298 times

From the 2nd graph, a Bell 204 Helicopter, hovering at 700 ft, and experiencing an engine failure, would not be able to recover with height below him to be able to make a safe landing!

[whirly]

FO Gyro,

Thanks!

I still wonder about a full engine out landing in a gyro though.Surely you will have a high rod as you push the nose down to gain the speed needed to autorotate, but somewhere close to the ground you need to stop that with a flare. If you just flare in a helo and don't pull the collective to further soften the landing you will smack the ground. Why is that different in a gyro? Maybe because you can keep a nose high attitude all the way to the landing, unlike a helo where you have to level it for fear of a tailstrike? Do they (gyros) just autorotate better??

Whirly.

[THI]

Hi Whirly,

I know it sound too good to be true, but that is as simple as it gets. When you have an engine out you take the correct glide slope and land the same way as you have practiced a hundred million time. Silly question, but have you ever flown is a gyro? If not, boy are you missing out! You should really go for a flip, do a (almost) engine out and see what happens. Pure joy!!

[Low Level]

From the 2nd graph, a Bell 204 Helicopter, hovering at 700 ft, and experiencing an engine failure, would not be able to recover with height below him to be able to make a safe landing!

THAT is a scary thought. I have never thought that a heli's envelope for safe autorotation is that large.

Surely you will have a high rod as you push the nose down to gain the speed needed to autorotate, but somewhere close to the ground you need to stop that with a flare.

Nose down to MAINTAIN autorotation. Maybe that is where the difference lie. Glide ratio is 4:1, and a normal flair can bring your speed down to zero for an absolute normal landing.

Whirly - maybe a stupid question or two. What is the glide ratio for a heli - engine out, and what is rotor speed in autorotation, compared to normal flying rotor speed ?

P.S. Glen - can't you split this from the Xenon thread. It is a good subject, and this thread becomes too large.

[whirly]

Guys,

Sorry about hi-jacking the Xenon thread!! It's the Xenon that has me all excited so I asked my questions here.

THI, I have never flown a gyro and has never cared to before the Xenon.

Low Level,

I have never watched the glide ration in a chopper..........................there isn't time for that!! Rotor rpm will differ from machine to machine but in the Alo II and III they will go up nicely and will go from 360 to 400 easily, you need to watch that when you flare or your rotor could overspeed. The more rpm in hand at the bottom the easier it is to land softly. The Jetranger and even the old Bell 47 are great machines when it comes to autos, not so are the R22 and Hughes 300C. The Hughes 500C is magic!

We practiced 800' hover autos in the Alo III in the SAAF and they are not nice but not a problem at all, I am sure it could be done lower but then your finger must be far out.

Are you saying that during an engine out in a gyro nothing actually changes?

Whirly.

[Yoda]

Whirly, Welcome to the gyro forum. I've been reading a lot of your posts on Avcom!!! and you even gave me some advice from time to time. Nice to have someone like yourself around.....

Regarding your last question on the Xenon Thread.... Yes, nothing changes when you loose you enjine on a gyro. Correct me if I'm wrong....
You must keep in mind that you will loose altitude quickly as in a Helikopter and you need to keep a good eye on your airspeed. Thing is, your forward speed will be a lot less than in a fixed wing on landing and chances for survival is substantially higher.
Maybe FO gyro can elaborate a little on the safety aspect, he is an airline pilot and seems to understand the technical stuff. Hierdie boertjie weet net van vlieg

On the subject of Gyrocopters vs Helikopters... its interesting. I've been around the chopper community for the past 2 months or so and one thing is for sure.... Most chopper pilots seems to think a gyro is unsafe... why I dont know but most chopper pilots first reaction on gyros are: I will never fly in that thing, they are to unsafe. Then I start to explane to them the whole concept of being in autorotation permanently being arguebly one of the safest forms of flying and they just look at me like... where do you come from.
As complicated, unstable, expensive etc etc the chopper is, as simple the gyro is. Just try to get around all the "complicatedness" of flying the chopper and you will probably "grasp" the concept of the gyro. A Gyro can be flown hands off. I suppose its not a very good idea in a chopper??

On that note: Helis vs gyros: If cost was not an issue.... which one would be your pic???? Whirly, why are you interested in starting to fly gyros? Is cost your only motivation or is there something else.. Looking forward to hear some responses.

[FO Gyro]

At the risk of sounding disloyal to gyro's, I think if I could afford to operate and own a helicopter, for me, that must be the ultimate. Ignoring the legal aspects, but being able to land on the top of a mountain, far from human civilisation must be a real fun. Imagine being able to have a picnic where no one else can get to? I just wish gyro's could do jump take-offs, now that would be spectacular!

I would imagine that the rate of descent of a gyro with the power off, and that of a helicopter during autorotation would be fairly similar. Maybe the chopper jocks could confirm this. Both in a gyro and helicopter, it is quite a steep glide angle. I think I'm correct in saying that the difference between a helicopter in autorotation and a gyro in a glide (that is always in autorotation) is that the airspeed to maintain is not nearly as critical in a gyro. In a helicopter, if you descent too quickly, the rotor RPM will redline, whereas in a gyro it doesn't matter. In a gyro, having sufficient airspeed to be able to arrest the rate of descent is the only important consideration.

[THI]

It is a pity gyro’s have such a bad name.

I read this on another form.

Promoting gyroplane safety through demonstration and education

Something we as gyro pilots must strive to!

[whirly]

At the risk of sounding disloyal to gyro's, I think if I could afford to operate and own a helicopter, for me, that must be the ultimate. Ignoring the legal aspects, but being able to land on the top of a mountain, far from human civilisation must be a real fun. Imagine being able to have a picnic where no one else can get to? I just wish gyro's could do jump take-offs, now that would be spectacular!

I would imagine that the rate of descent of a gyro with the power off, and that of a helicopter during autorotation would be fairly similar. Maybe the chopper jocks could confirm this. Both in a gyro and helicopter, it is quite a steep glide angle. I think I'm correct in sayin that the difference between a helicopter in autorotation and a gyro in a glide (that is always in autorotation) is that the airspeed to maintain is not nearly as critical in a gyro. In a helicopter, if you descent too quickly, the rotor RPM will redline, whereas in a gyro it doesn't matter. In a gyro, having sufficient airspeed to be able to arrest the rate of descent is the only important consideration.

FO Gyro,

Exactly!! Helicopters will always be my number one choice. But it would really be difficult to (sort of) justify owning one, and there are only two types that I would own anyway, when it's just the wife and I and all the flying would be for fun. The insurance and upkeep won't be worth it. I would settle for a gyro then and think it could be serious fun without breaking the bank! I could rent a helicopter to keep current as there is a school at George and hopefully there will be one at Mossel Bay soon.

Speed is very important in an autorotation in a helicopter, having too high a speed will mean a harder flare at the bottom with more inertia to arrest and a serious handfull of collective and definately not recommended. Rotor rpm is not a problem as you can control that by raising the collective as needed, this will extend your glide but a higher speed will shorten it so keeping to the correct speed is critical. Too low a speed and your rotor rpm will bleed off and you might not have enough at the bottom to properly cushion your landing, it's more dangerous than having a higher speed. You need airflow through the blades to turn them and the higher the better (within the design limits). Down at the coast (PE) we did power-off autos with the Alo III, landed it and picked it back up into the hover followed by a 180°hover turn and landing, that's how much inertia you had in the blades.

Would it mean that you can redline your rotor rpm in a gyro or does that not happen easily? Too slow during a "glide" in a gyro should also be more dangerous than too fast?

Whirly.

[FO Gyro]

Whirly, gyro manufacturers don't seem to have a redline or maximum rotor RPM. In a gyro, if you enter a steep turn, and load the rotor, the rotor RPM will increase, but before it reaches any serious RPM, if the steep turn is steep enough, the indicated airspeed will eventually bleed off - a total non-event.

In a glide in a gyro, flying too slow is absolutely fine. If you have some height, flying at zero airspeed is absolutely fine! I routinely approach over the threshold at 1500ft, slow the gyro down to zero airspeed, and allow the gyro to enter a vertical descent. At about 300 feet agl, I then lower the nose to allow the airspeed to increase from zero to around 60mph so that the gyro has enough energy to flare and land. (If you only start recovery at 200ft, with no power, that is when things can become pear shaped.) It confuses the fixed wing pilots big time when they see a gyro approaching from directly overhead the airfield!

[t-bird]

Hi FO Gyro

Is it not possible to over speed the rotors by doing a spiral dive in a Gyro ?