Aviomania's Agrinio Antics

[scandtours]

With just a c

It is important to understand that many lesser gyos would not have survived the maneuvers demonstrated by Nicolas on his Genesis and would have ended up in the bottom of smoking holes. Particularly full power climbs followed by a pushover.

That’s the advantage of a technically correct, properly engineered design.

CLT is only the beginning. Horizontal tailplanes set in the propeller slipstream with differential incidence to balance propeller torque prevent “torqueover” during periods at full power with reduced rotor thrust and low airspeed.

Those design features that contribute to safety also provide superior handling qualities.

It’s about time we had engineered designs rather by-guess-and-by-gosh scaled up Bensens.

With just a couple of lines, Mr Beaty, you've managed cover everything regarding Genesis handling qualities, including engine/prop torque stability.
It is as if you have flown Genesis. Did You?

 

[scandtours]

OK let me rephrase it!!!!

with that combination the Genesis has no problem flying behind the power curve add power and it will climb. With our 503 engined Genesis you can not do that.... raise the nose more and you sink even at full power.

The use of that phrase in my previous post was not intended to specify the exact meaning but it was supposed to be a few words description of the fact that the specific Gyro has a lot of reserved power to accelerate from a deep behind the power curve situation..... i hope that this came out right!!!!!

I will try to use proper English phrases in the future

Also this Gyro will not tail slide or fly back wards on a vertical descent like other short coupled gyros... even with engine off.. it will just weathercock in the direction of travel.. which means valuable seconds saved in reaction time.

Nicolas
That was the (...big but) I was going to explain before but did not had time.
You did it.

 

[PW_Plack]

OK let me rephrase it!!!!

with that combination the Genesis has no problem flying behind the power curve add power and it will climb...

Nicolas, I knew what you meant, and most folks here would know also, but you'll be under scrutiny from now on by people outside the gyroplane world. Non-standard use of terms may be portrayed as a literal claim. If you had available thrust which was greater than all-up weight, (and it's been done in airplanes,) you could hold altitude or climb at zero airspeed, but you'd still be behind the power curve.

It's called the power curve because it's an actual curve on a graph. I went fishing for one, and found this airplane power curve at http://www.allstar.fiu.edu/aero/airflylvl3.htm. While the exact shape of the curve would be a little different for a gyroplane, this one is close, and the minimum power required speed (MPRS), shown at about 60 here, (unknown whether knots or MPH,) would be lower for the gyro.

 

[All_In]

It is important to understand that many lesser gyos would not have survived the maneuvers demonstrated by Nicolas on his Genesis and would have ended up in the bottom of smoking holes. Particularly full power climbs followed by a pushover.

That’s the advantage of a technically correct, properly engineered design.

CLT is only the beginning. Horizontal tailplanes set in the propeller slipstream with differential incidence to balance propeller torque prevent “torqueover” during periods at full power with reduced rotor thrust and low airspeed.

Those design features that contribute to safety also provide superior handling qualities.

It’s about time we had engineered designs rather by-guess-and-by-gosh scaled up Bensens.

I cannot thank you enough Chuck for all you have taught me on this forum!!!

As my head Guru I pay close attention to everything you write. It was your comments that got me looking at the Genesis in the first place. I falsely believed Nic only sold ELSA so I could not register it in the States. I also own Leigh, big time too, as he straitened me out when at Mentone I came over to tell him I had finally selected my ride by observing how they all flew. A Sportcopter, Leigh said well your requirements are really better suited for a Genesis. I told him Chuck had pointed out the same advantages but Nicolas doesn't sell 51% build kits.
YES HE DOES, the rest is quickly becoming history.

Thank you Chuck for passing on your wisdom, I really appreciate you taking the time and everything you have done for us over the years!!!

You-Rock!

 

[Aviomania]

Nicolas, I knew what you meant, and most folks here would know also, but you'll be under scrutiny from now on by people outside the gyroplane world. Non-standard use of terms may be portrayed as a literal claim. If you had available thrust which was greater than all-up weight, (and it's been done in airplanes,) you could hold altitude or climb at zero airspeed, but you'd still be behind the power curve.

It's called the power curve because it's an actual curve on a graph. I went fishing for one, and found this airplane power curve at http://www.allstar.fiu.edu/aero/airflylvl3.htm. While the exact shape of the curve would be a little different for a gyroplane, this one is close, and the minimum power required speed (MPRS), shown at about 60 here, (unknown whether knots or MPH,) would be lower for the gyro.

Let me see if i will be able to write what i mean in English.... You are picking the words and not the meaning... My english language capabilities are to blame and the things that i thought others should understand.

lets take the manuver.... It is at 30 degrees nose up at 75-80% power flying straight and level at 15 -19 mph. AT THAT equilibrium i have the extra power available to climb. If i was flying at 45 degrees with full power then i would need to let the gyro sink to get the speed therefore reducing the disk angle and its drag so that it could accelerate. this is what happens with the 503. I can hold it only with full power at slightly less than 30 degrees nose up.

What is the deference though with the 582 is that the engine supports more weight than with the 503. what are the dangers?

Well the reason i am not flying slow at 45 deg. and full power is the answer.

first the rotor speed drops very low. i see 270- 290 RRPM in that maneuver. During early test with the genesis i have recovered it from 220 RRPm with the stick shaking like crazy. Now imagine if the engine quits. lowering the nose will reduce the RRPM further.

That is were the effective rudder of the Genesis will come into play and will give you a chance of landing it... heavy but you have the Chance.


So.... the meaning was that at the equilibrium of the maneuver ..... i had reserve power.

I did not mean that there is no way i will run out of power.... if this was the case... i could climb vertically.

I will be very careful next time.... i will try and explain what i mean better....... or if you learn Greek.... then it will be easier for me.... i think!!!

 

[scandtours]

PW_Plack
Again...,It simply means allowing the airspeed to get so slow that the engine can't maintain alt. EVEN AT FULL THROTTLE
But as Nicolas says in his case, by applying (the extra 30% power of the 582)will not only reduce the rate of descent significantly, but it will gain altitude.
What plays roll here is your all up weight, engine power and how efficient the rotor blades are.
Ive noticed that a gyro, with same engine but with dif rotor blades the results are not the same. Or same gyro with same blades but with dif engine. The curve line changes.
The theory you provide is correct.

 

[All_In]

John, Stan,

If need be we will train more people to prepare kits. We are looking into having some parts made from other vendors to increase our production.

Kits are easier to prepare than fully built. We will also try to keep our prices as low as possible. everything though increase so i do not know how long it will take for us to be forced to increase our prices.

Thank you Nic, I got builders ready and standing by here if Stan is too busy building!!

 

[PW_Plack]

Again...,It simply means allowing the airspeed to get so slow that the engine can't maintain alt. EVEN AT FULL THROTTLE...

Giogios, if you have adopted a alternative meaning for standard terms, we'll just have to agree to disagree. "Behind the power curve" means exactly what is says...you are operating on the side of the curve (on the left side of the curve in the diagram) where a further reduction in speed will require more power. If you are "ahead" or "in front of" the power curve, reducing speed will require a reduction in power.

"Behind the power curve" does not mean you have to be descending, or at the limits of available power.

 

[PW_Plack]

I will be very careful next time.... i will try and explain what i mean better....... or if you learn Greek.... then it will be easier for me.... i think!!!

Nicolas, I don't think this is so much a matter of English vs. Greek. I think this is just one of those terms which the gyro community uses differently from the rest of aviation.

You'll often hear gyroplane pilots say after a crash, "he got behind the power curve." That may be true, but ALL "slow flight" in gyroplanes occurs behind the power curve. It doesn't guarantee a crash, or even a descent. You can be climbing and still be behind the power curve.

Something similar happens with the term "blade flap." To a gyroplane pilot, it means he just spent at least $2K to fix the machine. To a helicopter pilot, it's something so routine that manufacturers provide a hinge for it.

Again, I only brought it up because if you're marketing to the general aviation market, the difference matters. And you have a machine which will have obvious appeal outside the pool of existing gyroplane enthusiasts!

 

[C. Beaty]

I cannot thank you enough Chuck for all you have taught me on this forum!!!

John Roundtree, when you hear someone say; “It’s so stable, it flies hands off,” keep looking, that person is confirming his ignorance about stability.

My first gyro, a sorta Bensen B-8 from 1967 with seat back tank and a large horizontal stabilizer was CLT and was sufficiently stable that I never thought much about stability.

Then, in the early 1980s, I bought a truckload of miscellaneous gyro junk. Included was a highly modified Bensen B-7 on which I installed an inverted Rotax 447 and mounted a JC Whitney fiberglass seat almost directly on the keel. By the time this picture had been taken, the engine had been flipped upright; slight help but not enough.

It was miserably unstable. We have a lot of thermal activity here in Florida in the summer when flying over areas alternating between green pastures and plowed fields; entering an upward thermal, it would pitch violently nose up and then nose down upon leaving; a backward arrow. Yet, with a Bensen offset gimbal rotorhead, it could be trimmed to fly very nicely “hands off.”

The last straw came when I fitted it with a collective pitch rotorhead, somewhat related to a Bell-47 system that fed no component of rotor thrust back into the cyclic stick. It then became a full time job just to stay right side up.

Thus began my stability odyssey. I didn’t have a computer at that time and little did I know that Cierva had already addressed that problem in the 1930s.

 

[scandtours]

Giogios, if you have adopted a alternative meaning
"Behind the power curve" does not mean you have to be descending, or at the limits of available power.

No, I am NOT adopting a alternative meaning, I was referring to "EXCESS POWER." What's that?

Somebody expressed it like this.

Let's just say that you're cruising along in that Speedwing 200 and you have just enough power set in to maintain level flight and that if you remove any power the old Speedwing will stall. If you just raise the nose of the aircraft in order to climb the aircraft will stall because of the increased drag from your pitching the nose up. Well then, how come you were able to climb in the earlier example? Ah, excess power Grasshopper. In that case the excess power was what enabled you to go faster than the "just before stall speed." Now I appreciate that the word "excess" makes it sound like you're doing something wrong or abusing your engine/s. You're not, it's just one of those aviation phrases that is commonly used.
Ive said it many times, PW_Plack, Your theory is correct
and you don't need to read the link below.

http://sifter.org/~simon/journal/20100718.h.html


.

 

[BEN S]

Guys...

Guys...

there is a huge difference between flying behind the power curve and flying in the deadmans curve. remember low and slow is a quick way to get killed! if you want to fly behind the power curve at 500ft agl go for it, but at 40 ft agl you have zero correction time.
Ben S

 

[EI-GYRO]

There are two expressions I have heard relating to slow flight.

The first is, ' on the back ( or back side ) of the power curve ' , which appears to be
within the area between the minimum power required speed ( the bottom of the curve ),
and the minimum speed at which level flight is possible at full power.

The second is ' behind the power curve' which I took to mean flying at a speed lower
than that at which level flight may be maintained with full power.

But I note that in common usage, the term 'behind the power curve' seems to be used for both situations.

 

[RotoPlane]

Talking about the "power curve" and using prop thrust, does not give a correct picture of "behind the power curve" height versus airspeed ratio. I look at it as a gyro being suspended at a height above the ground, engine off with the rotor at normal rpm….and then dropped.

A good height for that gyro will be one that allows it to have enough time to increase airspeed and regain rrpm, for a safe touchdown. This is from the top of the curve at 0 mph to the bottom, at an airspeed that it can safely land. Of course the height would drop with each faster starting airspeed.

This curve may appear to shrink with prop thrust….but loose the thrust and that curve will balloon back out to its original size and you will find yourself behind this "power" curve….and you will have a rough landing. The same is true if there is a headwind and it drops off.

I do not think Nicolas is being careless as he knows his machine very well and someone needs to demonstrate its capabilities and show the boundaries….he is the test pilot.

 

[PW_Plack]

Talking about the "power curve" and using prop thrust, does not give a correct picture of "behind the power curve" height versus airspeed ratio...

These curves are on two different graphs. The height/velocity curve is its own animal. You can be behind the power curve, without being in the dangerous area of the H/V curve, or vice-versa.

 

[PW_Plack]

...and that Day my job was " display pilot".../QUOTE]

This is an important distinction. I remember Jim Vanek taking flak for publicly performing his inside loop in a gyro, and it's kinda the same deal. On a recreational flight, these risks are inappropriate. In a demo flight, the mission alters the risk/reward picture.

Whatever risks Nicolas took to make this video, the reward has been increased sales of machines. That's a perfectly valid reason to accept increased risk, and experience and skill can mitigate it.

If you see a helicopter crew delivering a sling load in an urban area, evacuating a trauma patient from a crash scene on a highway, or inspecting power lines, you're seeing risks taken which would also not make sense on a recreational flight.

 

[willisbr]

I think to the sensible person it displays envelopes and boundaries in which the machine can tolerate. To the moron it displays "look what I can do if I buy this." I'm grateful for these types of videos and it has a lot to do with my shopping. As a matter of fact, I've asked Dofin to show me exactly what my RAF can do during my training. I developed an understanding of aerodynamics, limits, thresholds, whatever. Are the videos part of marketing? Sure. The vids tell you what you want to see and hear. Thousands of years have proven that you can't cure stupidity but we can sure hide from it by suppression, censorship, and "regulations". I say let the man fly and let the rest of us decide how we will fly. People will do what they want to anyway.

...and that Day my job was " display pilot".../QUOTE]

This is an important distinction. I remember Jim Vanek taking flak for publicly performing his inside loop in a gyro, and it's kinda the same deal. On a recreational flight, these risks are inappropriate. In a demo flight, the mission alters the risk/reward picture.

Whatever risks Nicolas took to make this video, the reward has been increased sales of machines. That's a perfectly valid reason to accept increased risk, and experience and skill can mitigate it.

If you see a helicopter crew delivering a sling load in an urban area, evacuating a trauma patient from a crash scene on a highway, or inspecting power lines, you're seeing risks taken which would also not make sense on a recreational flight.

 

[GyroChuck]

I say let the man fly and let the rest of us decide how we will fly. People will do what they want to anyway.

That's the way I think about it. People have also picked on Ron Awad about his flying. Just let the man fly.

 

[twistair]

...and that Day my job was " display pilot"...

This is an important distinction...In a demo flight, the mission alters the risk/reward picture.

Whatever risks Nicolas took to make this video, the reward has been increased sales of machines.

Well, I'll try to describe my point of view more accurately.

There are risks and there are risks. Each and every flight contains some part of risk. All in all flight safety procedures are no more than ways to minimize these risks. Some things bring serious limitations and give minor safety increase. Some habits need minimum efforts and give us significant safety increase. Say, preflight checks cost nothing but seriously decrease possible accident chance. On the other hand, BRS installed on a gyro would cost a lot of weight and money but gives too little if any since no one BRS was ever tested on a gyro.

I saw nothing extraordinary stunt in this video - all things that Nicos performed are more or less usual and safe for skilled pilot riding on a good gyro. Such flights look very attractive for everybody and, finally, they are what we're flying for - to enjoy ourselves and others.

The only thing which I didn't like in this video is that low altitude pass was made in not safest direction - directly and too close to the trees (Nicos told that there was enough space in front of him but I stay disagreed and this can be shown in numbers - there is about 250 ft only between runway and trees, and gyro's shadow on the grass shows the rest). My only claim is that there were other possible directions to make such low pass without obstacles in front of gyro.

Yes, I understand that demo flight must be spectacular (to increase sales as well). But in case of accident this turns not only on the pilot/saler but this also can ricochet a lot of other guys: bad media, angry sheriff (you gyroheads are always falling from the sky onto our public trees! etc), prospective customer wife frightened to death (you never buy this dangerous thing, do you promise?!) etc etc.

Just a simple thing of changing maneuver direction costs nothing and increases safety margin very well.

Same simple example: low pass at minimum level speed. Some call this "behind power cirve", we here use to call this "mode 2" (which in Russian aero tradition usually stands for powered flight at speeds lower than best glide speed). The most spectacular such low pass is where gyro is slightly higher than spectators' eyes. But if we remember dead man curve the most safe is to perform such pass at .5 - 1.0 feet height only - to make safe touch down in case of engine stop (I mean lower part of the curve - it's clear that the safest is to make this at 500 ft or higher).

We here use to instruct those who wants to perform something at airshows for the first time: well, guys, we know you're able to perform some certain stunt at, say, 10/10 (in terms of complexity). Don't do it at your edge here. Do perform this stunt at 7/10 today - just to increase safety margin. The main thing to understand is that this is not only certain flight safety. This is mostly safety margin for complete show success!

 

[willisbr]

We witness the same type of low altitude curve surfing in airshows where the guy flys the cub all over the place, yawing sideways with high attitude, etc and we say WOW! No one sh!ts on that because it's a certified aircraft or he's "experienced". Truth is, no one would go to an airshow, display, or give a gyro/any aircraft if all we did was ask everyone to fly left patterns at altitude. let's just all agree that it's a show??