accidents.. areas to avoid your advice

Devulsky

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There's a point in Devulsky's post above that is, IMHO, wrong. If you're flying @ 25 KIAS, and then some observer on the surface says he's measuring a wind of any magnitude and direction, you will still be flying at 25 KIAS... The flight performance of the aircraft is not affected by the measurements of that ground-based observer...
Thanks XXavier! I will try to change and explain better later.
 

GyroDoug

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Torque-over Issue

Torque-over Issue

This means designing the frame to have no net pitching moment (or better yet, a net positive pitching moment), taking into account the drag of the frame itself and the effect of thrustline placement. It also means building in some form of torque compensation to prevent torque-over. IOW, don't rely on rotor thrust either to hold the nose up against engine thrust or to resist the torque reaction from the prop.
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Doug,

I feel like I understand the pitch stability issue pretty well, and agree with everything you have said on the subject. However, I am not sure that I understand why you are as concerned about the torque-over issue you bring up. Do we have any accidents that we can specifically point to and say they were caused by the torque of the propeller turning the machine in the roll axis until it caused an accident? I would love to study this subject more so that I really have a solid understanding of it.

If I correctly understand the remedies that have been identified and proposed to correct this situation, the first would be the use of a Tall Tail. Then the next option would be to use differing angle of incidence on each side of the Horizontal Stabilizer. Would a trim tab set on the back of one or both sides of the Horizontal stabilizer, accomplish the same thing?

Please help me to better understand why this needs to be addressed at the design level and what options a designer has to accomplish this. And if you can point me towards any specific accidents that back up this concept I would really appreciate it.
 

cburg

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Related topics are canted thrust line, commonly used on other aircraft (easy/cheap but far less effective for this concern) and contra-rotating props (hard/expensive). If I believed it was a prevalent and recurring hazard I would opt for contra-rotating props.

Doug,

I feel like I understand the pitch stability issue pretty well, and agree with everything you have said on the subject. However, I am not sure that I understand why you are as concerned about the torque-over issue you bring up. Do we have any accidents that we can specifically point to and say they were caused by the torque of the propeller turning the machine in the roll axis until it caused an accident? I would love to study this subject more so that I really have a solid understanding of it.

If I correctly understand the remedies that have been identified and proposed to correct this situation, the first would be the use of a Tall Tail. Then the next option would be to use differing angle of incidence on each side of the Horizontal Stabilizer. Would a trim tab set on the back of one or both sides of the Horizontal stabilizer, accomplish the same thing?

Please help me to better understand why this needs to be addressed at the design level and what options a designer has to accomplish this. And if you can point me towards any specific accidents that back up this concept I would really appreciate it.
 

cburg

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Contra-rotating propellers have been found to be between 6% and 16% more efficient than normal propellers

Related topics are canted thrust line, commonly used on other aircraft (easy/cheap but far less effective for this concern) and contra-rotating props (hard/expensive). If I believed it was a prevalent and recurring hazard I would opt for contra-rotating props.
 

birdy

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we may find that weather, though scary, is rarely fatal in a gyro
And you may also find that shear or other bad air has caused more accidents than is believed.
Wouldnt supprise me one bit, given the level of ignorance of such little nasties floatn around out there, waitn for the unaware.
How often do you hear, "unexplained cause" , "unknown cause", "Unexplained control input", ................. .
Not only are so many ignorant of the possable conditions, they are just as ignorant of the effects it can have on controlability of the machine.
 

Penguin

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I liked this list so much that I taped it to my windscreen so I'd know what to avoid.
Taxied into a tree.
Better add that to the list.
:der:
 

Devulsky

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Can you imagine different ways to command a 0 g situation in a gyro than pushing the stick hardly forward?
Plenty of ways with oversped rotors.
Even long duration.[relitive for gyros]
Stick in any position and machine in any attude.
Pushing the stick hardly forward will create a situation. In stable gyro is recoverable? I am thinking as a supposed instructor and a student making this mistake.
 

XXavier

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Hello, Devulsky.

I really appreciate your extensive compilation in post #5 above, and hate to appear as a bore, but I wish to point out the persistence of the 'downwind turn' myth.

When you fly, you are moving as the motto of Nemo's Nautilus states: Mobilis in Mobili. You are moving within a moving medium, like when you're swimming in a moving river or walking on a moving walkway. Thus, when flying, and for matters other than navigation, it doesn't matter from where or how strongly does the wind blows in relation to the ground.

The danger of the 'downwind turn' appears when you fly keeping your direction with relation to the ground, having corrected for a lateral wind drift, and then turn downwind... In that case, you sink real fast... A frequent case is when turning 90º after take-off in a crosswind.

Regards
 

birdy

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Pushing the stick hardly forward will create a situation. In stable gyro is recoverable?
With oversped rotors and low load, the cyclic responce is MUCH faster, so its easy to over control, but its not as bad as it may seem, if you understand wots go'n on.
 

Devulsky

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Please evaluate...

Engine Failure or (off):
- Try to land beyond the MAXIMUM GLIDE RANGE (can lead to 0 G);
- On takeoff turn back to the runway;
- Too late change the landing site chosen.
 
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Devulsky

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(...) mast bump [ cyclic], bog the engine [collective], over speed the rotor [ collective] or loose TRE [ peddle].

Too agressive control inputs ina gyro can cause cyclic stall [ cyclic ], over coneing [ cyclic], torque over [peddle] or lateral drag over [ peddle].
(...)


Birdy,

Could you explain in more details?
 

WaspAir

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Please evaluate...

Engine Failure or (off):
- Try to land beyond the MAXIMUM GLIDE RANGE (can lead to 0 G);
- On takeoff turn back to the runway;
- Too late change the landing site chosen.
I think that middle one is more of an airplane issue. Airplanes need lots of room to land, and the runway tempts their pilots for a return, so people get scared and stall/spin out of a tight turn trying desperately to get back. There's no stall/spin risk with a gyroplane, and they're much less demanding for the size of a suitable landing spot in the terrain ahead. Poor judgment about whether/when/how to try it shows up in the airplane statistics, but I don't recall seeing that as a cause in gyroplane accident reports.

I don't quite understand the 0 g reference for glide stretching in the first one; the real risk in over estimating your range is hitting something between you and the desired landing spot, not a zero g condition.
 

Devulsky

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Thanks Waspair

I think that middle one is more of an airplane issue. Airplanes need lots of room to land, and the runway tempts their pilots for a return, so people get scared and stall/spin out of a tight turn trying desperately to get back. There's no stall/spin risk with a gyroplane, and they're much less demanding for the size of a suitable landing spot in the terrain ahead. Poor judgment about whether/when/how to try it shows up in the airplane statistics, but I don't recall seeing that as a cause in gyroplane accident reports.

I don't quite understand the 0 g reference for glide stretching in the first one; the real risk in over estimating your range is hitting something between you and the desired landing spot, not a zero g condition.

1. Try to land beyond the MAXIMUM GLIDE RANGE;

I know of at least two other accidents that may have been caused by item 1

1. one fatal in Brazil when the pilot tried not to land on the river, stretching. I really cannot say that was a 0G case but fatal.
And another in germany (i will try to find the link) when witnesses said the aircraft lost engine and tried to reach the runway. Both hit the ground and did not hit other objects.

2. On takeoff turn back to the runway;

This tip is from the Calidus manual: Low velocity, low altitude and engine-off and try to turn is not recommended there.

3. Too late change the landing site chosen/glide stretching.

This is one http://www.dailyrecord.co.uk/news/uk-world-news/tragic-gyrocopter-pilot-hailed-hero-1101606 but I've read other similar cases.
 

Vance

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You have taken on an interesting and challenging task Aerial.

You have taken on an interesting and challenging task Aerial.

Thanks Waspair




1. Try to land beyond the MAXIMUM GLIDE RANGE;

I know of at least two other accidents that may have been caused by item 1

1. one fatal in Brazil when the pilot tried not to land on the river, stretching. I really cannot say that was a 0G case but fatal.
And another in germany (i will try to find the link) when witnesses said the aircraft lost engine and tried to reach the runway. Both hit the ground and did not hit other objects.

This is one http://www.dailyrecord.co.uk/news/uk-world-news/tragic-gyrocopter-pilot-hailed-hero-1101606 but I've read other similar cases.
How do you stretch a power off glide in a gyroplane?

I was practicing takeoffs and landings yesterday in The Predator, a one of a kind two place tandem gyroplane; I could not find a way to extend my glide.

The winds were 270 at 18kts gusting to 28kts landing and departing on runway 30.

It appeared that the best glide distance was achieved at just under 50kts although the slowest rate of descent is a little slower but that appeared to me to shorten the glide distance.

If I found I was going to land short of my target because of a prolonged gust I could not find a way to extend my glide.

Nothing I did in an effort to extend the glide made the touchdown less gentle.

What do you feel is dangerous about trying to extend the glide Ariel?

I read the story on the Accident in England and I don’t see how trying to extend the glide contributed to it unless he found a less suitable landing zone.

If anyone knows how to extend the glide I would love to read about it.

I find it is easy to shorten the approach if I feel like I am going to over shoot my target but I have not found a way to extend my glide.

Thank you, Vance
 

Doug Riley

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Vance, you're too smart to be taken in by the fallacy, but a beginner may wrongly pull back the stick in an effort to stretch a glide.

The general public has been brought up on TV shows and movies in which the hero can always make an aircraft climb by pulling back dramatically on the stick.

The inexperienced pilot at first feels that this "technique" is working, as the nose does rise. Only after a moment or two does he-she realize that the gyro has slowed down and begun to mush in at a steeper angle than before.

This happened more often in the bad old days, when self-training was the dominant method of gyro flight training.

The problem is not that engine failures lead to zero G (they don't). They do lead to various failures to conserve the remaining usable energy of the gyro (altitude + airspeed + blade RPM) so that you don't run out of energy before you have flared for landing.
 

Devulsky

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How do you stretch a power off glide in a gyroplane?

What do you feel is dangerous about trying to extend the glide Ariel?

Thank you, Vance
Well... we are always learning here, especially me. I am not saying that this is possible. I am conjecturing if a unexperienced or desperate pilot can try to climb, low rpm, etc. or any other manouver that may worsen the situation.

Thanks!
 

Vance

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Help with gyroplane safety!

Help with gyroplane safety!

Thank you for suggesting that I am smart Doug.

I like to try things and sometimes the results suggest I am not that smart.

The query was triggered by the suggesting that trying to extend the glide was dangerous.

If there is a way to extend the glide I would like to know about it.

I feel you have probably identified the reason for the warning.

I feel the warning would be more helpful if it was a little more complete.


It sounds like you are aligned with Doug Aerial and in my experience that is a sign you are on the correct path.

I appreciate what you are trying to do and I am a decision tree enthusiast. It is my hope you are headed in that direction.

Thank you for your efforts to help us be safer pilots.

I have found that forethought reduces the decision making time when time is of the essence.


I feel you have it Stan.

That is precisely the kind of elucidation I would like to see in a Pilot’s Operating Handbooks.

If only you were writing the POH I feel they would be more helpful.

I feel a vague reference to a hazard only limits my options without guiding me toward a better outcome.

Thank you, Vance
 

Devulsky

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Thank you for suggesting that I am smart Doug.
I feel the warning would be more helpful if it was a little more complete.
I Agree. Can you help us to complete?

That is precisely the kind of elucidation I would like to see in a Pilot’s Operating Handbooks.
If only you were writing the POH I feel they would be more helpful.
I think you are more prepared to do this.

I feel a vague reference to a hazard only limits my options without guiding me toward a better outcome.
Thank you, Vance
Very vague, but at the beginning it is perfectly normal. This tree was assembled in a few days. I don`t think we could create a compendium about Gyrocopter Flight Safety in 3 days. That is not the objective.

I've read many posts from you. I know your skill level is above average. Really, it is useless to a specialist. For me it is useful for two reasons. 1. Surely someone like me will read and learn something. 2. I am learning and doing my part.
 
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