AR-1 N923DJ Texas 15-12-18

Vance

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From Kolibri's post 71.
"I see two different forms of "insurance" when landing during turbulence:

1) Drop in mostly vertically from the classic 20' roundout/initial flare but with maybe a bit more power for rudder authority.
(RISK: pancaking in below 5-10 feet from loss of lift and/or downdraft.)

2) Fly through mostly horizontally after a within-rotorwash roundout, flying at 1-2 feet to the full-flare landing.
(RISK: being involuntarily set down by a strong downdraft with a-higher-than-desired-though-not-necessarily-unsafe groundspeed,)

As I and others see it, #2 shortens the amount of time in a block of turbulence, and reduces the vertical impact component.
During either technique, one must pass through what I consider the vulnerable altitude of 3-10 feet.
I'd rather pass through that with more speed and lower to the deck than technique #1."

Rotor wash: air turbulence caused by a helicopter rotor.

Perhaps Kolibri is writing about ground effect.

The Principals of ground effect according to Wikipedia:
When an aircraft flies at a ground level approximately at or below the half length of the aircraft's wingspan or helicopter's rotor diameter, there occurs, depending on airfoil and aircraft design, an often noticeable ground effect.

So a gyroplane with a thirty foot diameter rotor that is ten feet in the air needs to be less than five feet above the ground to experience ground effect.

In my opinion fling a gyroplane less than five feet above the ground at fifty to sixty knots is dangerous and pointless.

There is a third option; round out at fifteen feet and land normally with a little more power to enhance rudder authority.

In my opinion based on my experience flying in strong gusting winds; Kolibri’s method is dangerous and relies on a consistency of conditions that simply don't exist anywhere I fly.

I have clients try something approaching the Kolibri method in calm winds and quickly abandon it the first time they fly in strong (15kts to 25kts) gusting winds.

Kolibri's fantasies about the wind and how it affects a gyroplane during a landing are unrelated to what I experience flying in California, Arizona, Utah, Indiana, Wisconsin and Florida.

I don't understand why a low time gyroplane pilot imagines that they have thought about it enough to invent a new way of landing a gyroplane in strong gusting winds that is safer without trying it.

I am confident that Kolibri does not have the skill set to land as he describes.

Try flying the length of the runway at 60kts indicated air speed 50 feet above the ground in strong gusting winds and I suspect you will discover why it is a bad idea to fly at 60kts indicated air speed five feet above the ground.
 

Vance

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What Kolibri claims in post 71: "When Vance landed at Victorville during extreme gusts with mountain wave action and rotors off the hangars, he posted that he lost lift from 20' at 30mph AS.
That placed him right on the H:V line, and little wonder that he barely saved himself with aggressive application of power.
(From above that 20' while <42mph, he was vertically descending within the hatched no-fly area.)"

It appears to me that Kolibri exaggerates for the sake of drama.

What I wrote:

I asked for a wind check and it was 150 degrees at 28 gusting to 38.

I slowed to 30kts indicated air speed and made a vertical descent to the ground at the intersection of runway 21 and taxiway Bravo with a little excitement near the end when the wind speed diminished. Touch down was as nice as could be with a burst of power and no forward speed.

30kts indicated air speed is 34.5 miles per hour and I typically begin my round out at 15 feet and 50kts so I was probably lower when I reached 30kts knots indicated air speed.

Federal Meterological Handbook No.1 chapter 5:
5.4.4 Wind Gust. Gusts are indicated by rapid fluctuations in wind speed with a variation of 10 knots or more between peaks and lulls. The speed of a gust shall be the maximum instantaneous wind speed.

A ten knot gust is only a barely reportable gust, hardly "extreme gusts."
 

thomasant

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I find it interesting to observe on this thread some references by posters as to what I may have experienced.
According to my logbook, I have over 6100 landings by day. I need to remind myself regularly that a gyroplane is not a helicopter, nor an airplane. It is a gyroplane and has its unique characteristics. Airplane pilots sometimes forget that a gyroplane cannot stall, but the rotors can stall if the conditions are right. Helicopter pilots sometimes forget that the gyroplane cannot hover in still air and there is no collective to cushion the landing. The most sobering fact is that a rotating rotor packs a punch unlike any fixed wing even at zero ground speed.
For me personally, the landing itself is a non event, except for the accident one. IMHO, there is no point in getting bogged down by the numbers of whether 4 or 5 feet height, or 10 or 15 mph ground speed, or 15 to 20 mph wind speed gusting can make a huge impact on the landing, unless one is ill prepared to deal with a situation which entails a go round.
During my accident landing, I was not prepared for a condition that I now believe could have caused an airflow reversal on my rotors unlike any gust or wind shear that I have experienced. What I have since learned from this experience is that aggressive turns and flares close to the ground can cause an over speed of the rotor, and the consequences of that over speeding can cause a situation which may be difficult to handle if close to the ground.
Regarding what technique to use for a landing under crosswind or gusting conditions, I believe Fara, Vance and WaspAir have covered the topics which I believe are tried and true.
 

C. Beaty

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Antony, if you go through the NTSB accident statistics, you’ll find that nearly all rollovers occur with gyros having rudder/nosewheel coupling.

That’s not to say you weren’t the victim of some freakish occurrence but back in the day when I was flying high inertia, tip weighted rotor blades that would thump you down if normal landing procedure was followed, I enjoyed rolling out of a tight turn immediately prior to landing and playing helicopter for a few seconds.

High inertia rotor blades such as from a Hughes OH-6 accelerate more slowly than low inertia blades so during the landing flare, more time must be allowed for the blades to accelerate and develop the extra lift to cushion the landing.

Pilots often mistake tail heavy blades for high inertia blades. Tail heaviness provides pseudo collective pitch that can also cushion a landing.
**************
It just occurred to me that when playing helicopter using excess energy from rolling out of a tight turn, the gyro really is helicoptering and if the gyro is too high, the transition back to gyrocoptering might be fairly abrupt, involving a bit of a drop.
 

WaspAir

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Kolibri;n1141183 said:
When Vance landed at Victorville during extreme gusts with mountain wave action and rotors off the hangars, he posted that he lost lift from 20' at 30mph AS.
That placed him right on the H:V line, and little wonder that he barely saved himself with aggressive application of power.
I think you misapprehend the nature of the H-V diagram. The avoid region reflects an unwise energy state for continuous operation, a serious matter especially for climb out and cruise phases of flight (note that I did not say landing phase, for reasons to follow). The underlying theory is that if an unexpected engine failure happened while flying along at the speed and altitude combinations shown, while you are dependent upon the engine to maintain flight, it would be difficult to put the aircraft down safely if a surprise emergency landing became suddenly necessary. But if you are already in the process of landing on short final, already descending, and already at a greatly reduced power setting as is customary on final, while merely clipping the corner of the avoid region for a brief moment, it is not at all the same risk as continuous powered operation there. Moreover, the HV diagram is not intended to address atmospheric surprises such as wind shear, but engine out dangers for those who would otherwise cruise/climb along blithely ignoring risks of power failures. I think you misstate the nature and the severity of the risk faced by Vance when you describe it in HV terms.
 

WaspAir

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Kolibri;n1141183 said:
If the gyro is very low to the runway before the full-flare/touchdown, and one is gradually reducing power meanwhile, and there is hardly any settling from 2 feet, what else can RRPM do but decay?
The gradual aft stick adds a little bit of load (and thus RRPM), but (unless you balloon) not more than the simultaneous slowing AS decays RRPM.
I.e., there is a slight and gradual net loss of RRPM. (Or do you touchdown with cruise AS level of RRPM?)
Timed correctly, most of the rotorwash has been dissipated by the time one reaches nearly 0 groundspeed.[/COLOR]
Whatever would inspire you to fly along at two feet without any settling? If you want to get farther down the runway, aim farther down, don't aim early and float to it. Otherwise, if that's not what you want, don't stop at two feet, just keep descending and LAND.
I teach (and fly) the "roundout" and "flare" as the beginning and end of one uninterrupted continuous process. My face is smiling when I reach a few inches of altitude and zero ground speed at the same time, with a high deck angle, and find myself sitting on the mains (nose up) just a moment later. Between 50 feet and 0 feet I perform no level flight at all. Rotor rpm DOES NOT decrease in this process. The behavior you describe (slight and gradual net loss of RRPM) simply doesn't happen, and makes absolutely no sense from the standpoint of basic physics or from my rather extensive experience.

Please use "ground effect" if that is what you mean; your use of "rotorwash" seems to be nonstandard and is confusing.
 

thomasant

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WaspAir;n1141213 said:
I teach (and fly) the "roundout" and "flare" as the beginning and end of one uninterrupted continuous process. My face is smiling when I reach a few inches of altitude and zero ground speed at the same time, with a high deck angle, and find myself sitting on the mains (nose up) just a moment later. Between 50 feet and 0 feet I perform no level flight at all. Rotor rpm DOES NOT decrease in this process. The behavior you describe (slight and gradual net loss of RRPM) simply doesn't happen, and makes absolutely no sense from the standpoint of basic physics or from my rather extensive experience.
Therein is the essence of the "Flare" and the term "Happy Landings". I find it hard to understand how anyone could execute a successful flare and landing any other way.



"It just occurred to me that when playing helicopter using excess energy from rolling out of a tight turn, the gyro really is helicoptering and if the gyro is too high, the transition back to gyrocoptering might be fairly abrupt, involving a bit of a drop."
Thank you Chuck
, I appreciate your insight.


Well, I guess having to pay for a new set of rotors, prop, etc is the cost of an education. I'm just thankful that I'm alive and in one piece. I shudder at the prospect of what could have been. Dead or hospitalized with serious injuries and untold hospital bills without the ability to work!

I hope this thread has given some useful insight. Pointless for folks to continue arguing about anything else in this thread. I actually thank SteveUK for bringing this thread out.
 

Kolibri

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It appears to me that Kolibri exaggerates [my Victorville landing] for the sake of drama.
Not really, Vance.
Your truncated account here left out the most important thing: when the gust subsided you were at 20 feet, and you barely saved it with the prompt application of power.
Here is your own description from another thread:


I was making a vertical descent from about 20 feet when the gust went away and dropped us down pretty quickly. I added power and flared aggressively
(You'd already rounded out, thus above 20 feet.)
Let's be honest: Had that happened a couple of feet lower, or had the gust subsided more, you'd have dropped in hard.
What I summarized then I still believe: you were operating at that moment with very little margin for safety.
My impression is that you do so more often than you realize.


_____
So a gyroplane with a thirty foot diameter rotor that is ten feet in the air needs to be less than five feet above the ground to experience ground effect.
IIRC, my 30' rotors are not 10' high, but about 9'. Thus, a roundout/initial flare at 6 feet for me is within ground effect. It certainly feels like it.

I don't understand why a low time gyroplane pilot imagines that they have thought about it enough to invent a new way of landing a gyroplane in strong gusting winds that is safer without trying it.
Real professional of you to implicitly call me a liar, Vance.
a) I didn't claim to invent it, and b) I've used it many times.

It is axiomatic that flight inertia which is more horizontal than vertical will better handle turbulence, as well as more quickly penetrate a dirty block of air.
And the lower to the ground one does so, the less the turbulence and the less drama it can impress upon the aircraft.
If, for example, I'm plopped down from 1 foot at 10mph, it's merely a hard landing of slightly involuntarily timing.
However, get plopped down from 4 feet . . .

But, hey, keep dropping in mostly vertically from your classic 20 foot roundout. You've already admitted to many close calls.



I am confident that Kolibri does not have the skill set to land as he describes.
I am confident that nobody flying with one-eyed vision has the required depth perception to confidently and consistently roundout/initial flare at 6 feet.
For such a pilot, such would indeed probably be a bad idea, or even dangerous.

Regarding Vance's calling B.S. on me, I've GoPro videos of my training days in a Calidus rounding out at or below 6 feet.
I could do so then in my first several hours of gyro flying. (I was already a PP-ASEL, thus not an ab initio pilot.)
Only one time did my CFI Chris Lord ever reach for the stick, and that was when I experimented with rounding out at probably 3 feet.
I had already preceded his reaction with ample back stick, and he apologized for nearly adding to it as he thought we might have pancaked in.
I apologized for not giving him a heads up that I was going for a bit lower that time.

Just to make sure I wasn't misremembering things, I reviewed some of those landings. I was definitely rounding out in ground effect.
In fact, I watched the stick dip forward a tiny bit to compensate for the initial cushioning and not balloon up.
I.e., instead of using back stick to arrest descent in my roundout, I was using the gyro's ground effect to arrest my descent.
The video is also clear enough to carefully see the altimeter at roundout vs. touchdown.

So, anybody sufficiently confident that I do not have the skill set to land as I've described, should PM me to place a $$$$ wager on it.
I'll install my GoPro and gather some witnesses to also film it from the ground.



Try flying the length of the runway at 60kts indicated air speed 50 feet above the ground in strong gusting winds
and I suspect you will discover why it is a bad idea to fly at 60kts indicated air speed five feet above the ground.
Wow, really? This assertion from a gyro CFI?
It's not a
"bad idea" because . . . gusts and wind shear are less severe at 5' than 50'.
You've said so yourself many times: downdrafts don't reach the ground, they decrease in velocity the lower they go, etc.
Ever seen a winds aloft table? Winds are almost always stronger with altitude.

Doesn't anybody recall their earliest student pilot landings during gusty crosswinds?
On short final at 100 feet being buffeted around, and having the CFI assuage your nervousness with "
Don't worry, ride this out, things will settle down once you're lower to the runway."
He was right, and I often say the same thing to any nervous passenger during a gusty short final.

So, I've NO IDEA why getting quickly low and below much of the turbulence is so controversial here.
My CFI can't understand it, either.



___________
Please use "ground effect" if that is what you mean; your use of "rotorwash" seems to be nonstandard and is confusing.
Fair enough, WaspAir, willco.

But if you are already in the process of landing on short final, already descending, and already at a greatly reduced power setting as is customary on final, while merely clipping the corner of the avoid region for a brief moment, it is not at all the same risk as continuous powered operation there. Moreover, the HV diagram is not intended to address atmospheric surprises such as wind shear, but engine out dangers for those who would otherwise cruise/climb along blithely ignoring risks of power failures
Yes, I agree with all that.

I think you misstate the nature and the severity of the risk faced by Vance when you describe it in HV terms.
I disagree. He didn't even lose engine power, but merely experienced a subsided gust, and yet he still nearly crunched in.
His own account corroborated what it's like to be right on the H:V line when something unexpected happens.


Whatever would inspire you to fly along at two feet without any settling? If you want to get farther down the runway, aim farther down, don't aim early and float to it.
Otherwise, if that's not what you want, don't stop at two feet, just keep descending and LAND.
I wrote "hardly any" settling.

Between 50 feet and 0 feet I perform no level flight at all. Rotor rpm DOES NOT decrease in this process.
The behavior you describe (slight and gradual net loss of RRPM) simply doesn't happen, and makes absolutely no sense from the standpoint of basic physics or from my rather extensive experience.
During such a vertical descent with no level flight, sure, I agree. In fact, I've already conceded that, as the rotor is consistently loaded.

However, during turbulence I've been describing a much flatter descent, with less rotor loading between the roundout/initial flare and the full flare landing.
There is very little [additional] rotor loading from 6 feet to 0 feet, but much more reduction in AS. Thus the slight RRPM decay within the lower 300s.
Why this is so difficult to accept for some, I don't know. Perhaps I should film it as proof?



____________
During my accident landing, I was not prepared for a condition that I now believe could have caused an airflow reversal on my rotors unlike any gust or wind shear that I have experienced. What I have since learned from this experience is that aggressive turns and flares close to the ground can cause an over speed of the rotor, and the consequences of that over speeding can cause a situation which may be difficult to handle if close to the ground.
Antony, I've played around with high-G base-final turns and noticed the increased RRPM.
However, I've found it to quickly dissipate and RRPM returns to normal values for the AS.
I don't recall any base-final overspeeded RRPM lasting into the roundout.

Since you didn't describe your flare as anything vigorus, nor mention any ballooning, it's hard for me to envision an oversped rotor from that flare.

But, if, now, you've come to believe that when you were at 4 feet and 10mph that you still had some overspeeded RRPM from either your turn or your flare,
which then began to decay causing an airflow reversal and sink, then I hope you're correct in your appraisal and have learned what you needed to learn.

However, since you're a gyro CFI, I admit to some surprise that this was something you didn't already know.

The other thing that surprised me was that you actually closed your eyes before impact.
As Bob Hoover was famous for saying,
"Fly the aircraft all the way into the crash."
I've actually commanded myself to "Aviate! " during dicey moments, and it helps.

_____
Thanks for everyone's participation; it's been enlightening, and my particular thanks to Antony for sharing his experience here.

Safe flying,
Kolibri
 

WaspAir

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Kolibri;n1141231 said:
During such a vertical descent with no level flight, sure, I agree. In fact, I've already conceded that, as the rotor is consistently loaded.

However, during turbulence I've been describing a much flatter descent, with less rotor loading between the roundout/initial flare and the full flare landing.
There is very little rotor loading from 6 feet to 0 feet, but much more reduction in AS. Thus the slight RRPM decay within the lower 300s.
Why this is so difficult to accept for some, I don't know. Perhaps I should film it as proof?[/COLOR]
I'll try one last time here.

First, for clarity, I did not advocate any "vertical descent" in my description of continuous uninterrupted roundout and flare without intervening level flight. An approach with a 4:1 glide is about 14 degrees from horizontal. An airplane pilot used to long 3 degree VASI approaches (19:1 glide) would find it steep, but rotorcraft pilots don't.

I strongly suggest that the time between 6 feet and 0 feet is exactly when the rotor loading should be highest.

If you want to avoid getting tossed around, put the thing down; don't prolong the hazards or fly through more air when you don't need to.
 

Kolibri

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First, for clarity, I did not advocate any "vertical descent" in my description of continuous uninterrupted roundout and flare without intervening level flight.
WaspAir, regardless of what you advocate, vertical descent seemed exactly what you described:

Between 50 feet and 0 feet I perform no level flight at all. Rotor rpm DOES NOT decrease in this process.

__________
If you want to avoid getting tossed around, put the thing down; don't prolong the hazards or fly through more air when you don't need to.
You seem to be imagining that I'm floating for hundreds of feet. I'm not. I am putting the thing down.

It's almost like the FW technique of "
flying it to the ground" during turbulence.
(On the way to 2013 Oshkosh, I recall my FW go-around from Runway 30 at MML, where I flubbed the classic roundout and flare continuum.
Winds were variable and gusting, so I tried Runway 2, and that time very deliberately flew it right to the ground with a decent flare touching only the mains.
Just watched those videos. They were, back to back, my worst and best FW landings that summer.)

Back to gyro landings in turbulence, I get lower more quickly.
The hazards are less there. The winds are less severe there.

I suspect that my time between roundout and touchdown is also less.
In fact, my Calidus training video I just reviewed shows a time interval of 4-5 seconds.
How is that prolonging any hazards?

Regards,
Kolibri
 

thomasant

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Kolibri, I don't understand what your problem is. You also have a way of misstating the facts as narrated.

Did you know of the condition described by Birdy/Doug/Chuck before this thread? I did not. I also discussed this condition with a couple of other CFIs, and they did not know either. Go and take some training and become a gyro CFI is my recommendation to you.

What I wrote is:
"When I felt the impact, which was significant, I heard the engine go quiet and I instinctively knew that the prop had stopped. There was the sound that I heard, probably of the prop striking, and I knew then that I was toast. I actually closed my eyes and felt the rotors impact and when I opened them again, I was tipped over to the right side."

You can see that I closed my eyes after the impact. What is it that you do not get in my statement?

I have no desire to continue this with you. You requested me to narrate the details so that you could learn something. I do not wish to get dragged into your arguments.
 

Kolibri

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Antony, you're right; you closed your eyes after the first impact, but before the rotors struck and you turned over.
Your gyro hadn't yet come to rest. I only quoted Bob Hoover's dictum for us all: to never stop flying the aircraft whilst in motion.
I wasn't trying to belittle or badger you.

Sink from airflow reversal via helo-esque hovering to a gyro's auto-rotation: no, I hadn't heard it explained like that, either.
Being neither helo pilot nor gyro CFI, I don't know what they generally know or not.
But, I was surprised that such a phenomenon would be a revelation to anyone in that level of aviation.
I meant no personal dig, but regrettably did not express myself clearly enough to prevent unintentional offense, so I apologize for that.

Regards,
Kolibri
 

WaspAir

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Kolibri;n1141235 said:
WaspAir, regardless of what you advocate, vertical descent seemed exactly what you described
Are you being intentionally obtuse?

I described a continuous roundout and flare, with no period of level flight in between, on final approach (this was to draw contrast to a procedure you seemed to describe as three steps, with a roundout, followed by level flight at a steady low altitude while rotor rpm decreases, then followed by a flare).

I cannot imagine how anybody could construe my procedure to be a vertical descent. Are we once again wrestling with non-standard usage by you of otherwise standard vocabulary?

Vertical descent means your path is 90 degrees (perpendicular) to the ground. All motion is vertical. No motion is horizontal. That's basic geometry. The notion of roundout and cyclic flare is ridiculous in that context, because both require forward speed, and that makes your reading of my description pretty bizarre.

Level flight means your path is 0 degrees (parallel) to the ground. All motion is horizontal. No motion is vertical. That is also basic geometry.

I do not advocate either vertical descents or level flight on short final.

Your suggested procedure involves rounding out after descending close to the ground, arresting the descent after roundout, briefly flying level at a low fixed altitude, and then performing a flare. You countenance a loss of rotor rpm between 6 and 0 feet.

I find that, at best, an unproductive carry-over from bad fixed wing habits, and at worst, foolhardy.

I applaud your concerns for safety, but find your procedural advice unwise and highly unhelpful.
 

Kolibri

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No, not intentionally obtuse, I'd not realized that you were still stuck on my mentioning in passing about brief level flight at 2 feet.

From my post 71, the green line illustrates what I've been trying to describe. It's a very flat slope (i.e., more level than not):
green line on HV diagram.png



However, even if one did not descend so slightly, but kept level for a short distance at 2 feet while bleeding off airspeed,
how is that worse in turbulence than floating down at 14 degrees in a classic gyro descent?

Simple (and yet unaswered) question: when turbulence is present, is it generally stronger at 0-10 feet or at 20-50 feet?
That's been my central point in this entire thread.

During turbulence, I want to negate as much of it as possible by getting lower ASAP.
What turbulence remains will pose less risk because I've nearly no height left to drop from and my strong ground effect acts as cushion/spring against downdraft energy.


Regards,
Kolibri
 

Vance

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Kolibri;n1141231 said:
Not really, Vance.
Your truncated account here left out the most important thing: when the gust subsided you were at 20 feet, and you barely saved it with the prompt application of power.
Here is your own description from another thread:



(You'd already rounded out, thus above 20 feet.)
Let's be honest: Had that happened a couple of feet lower, or had the gust subsided more, you'd have dropped in hard.
What I summarized then I still believe: you were operating at that moment with very little margin for safety.
My impression is that you do so more often than you realize.


_____

IIRC, my 30' rotors are not 10' high, but about 9'. Thus, a roundout/initial flare at 6 feet for me is within ground effect. It certainly feels like it.


Real professional of you to implicitly call me a liar, Vance.
a) I didn't claim to invent it, and b) I've used it many times.

It is axiomatic that flight inertia which is more horizontal than vertical will better handle turbulence, as well as more quickly penetrate a dirty block of air.
And the lower to the ground one does so, the less the turbulence and the less drama it can impress upon the aircraft.
If, for example, I'm plopped down from 1 foot at 10mph, it's merely a hard landing of slightly involuntarily timing.
However, get plopped down from 4 feet . . .

But, hey, keep dropping in mostly vertically from your classic 20 foot roundout. You've already admitted to many close calls.




I am confident that nobody flying with one-eyed vision has the required depth perception to confidently and consistently roundout/initial flare at 6 feet.
For such a pilot, such would indeed probably be a bad idea, or even dangerous.

Regarding Vance's calling B.S. on me, I've GoPro videos of my training days in a Calidus rounding out at or below 6 feet.
I could do so then in my first several hours of gyro flying. (I was already a PP-ASEL, thus not an ab initio pilot.)
Only one time did my CFI Chris Lord ever reach for the stick, and that was when I experimented with rounding out at probably 3 feet.
I had already preceded his reaction with ample back stick, and he apologized for nearly adding to it as he thought we might have pancaked in.
I apologized for not giving him a heads up that I was going for a bit lower that time.

Just to make sure I wasn't misremembering things, I reviewed some of those landings. I was definitely rounding out in ground effect.
In fact, I watched the stick dip forward a tiny bit to compensate for the initial cushioning and not balloon up.
I.e., instead of using back stick to arrest descent in my roundout, I was using the gyro's ground effect to arrest my descent.
The video is also clear enough to carefully see the altimeter at roundout vs. touchdown.

So, anybody sufficiently confident that I do not have the skill set to land as I've described, should PM me to place a $$$$ wager on it.
I'll install my GoPro and gather some witnesses to also film it from the ground.




Wow, really? This assertion from a gyro CFI?
It's not a
"bad idea" because . . . gusts and wind shear are less severe at 5' than 50'.
You've said so yourself many times: downdrafts don't reach the ground, they decrease in velocity the lower they go, etc.
Ever seen a winds aloft table? Winds are almost always stronger with altitude.

Doesn't anybody recall their earliest student pilot landings during gusty crosswinds?
On short final at 100 feet being buffeted around, and having the CFI assuage your nervousness with "
Don't worry, ride this out, things will settle down once you're lower to the runway."
He was right, and I often say the same thing to any nervous passenger during a gusty short final.

So, I've NO IDEA why getting quickly low and below much of the turbulence is so controversial here.
My CFI can't understand it, either.



___________

Fair enough, WaspAir, willco.


Yes, I agree with all that.


I disagree. He didn't even lose engine power, but merely experienced a subsided gust, and yet he still nearly crunched in.
His own account corroborated what it's like to be right on the H:V line when something unexpected happens.



I wrote "hardly any" settling.


During such a vertical descent with no level flight, sure, I agree. In fact, I've already conceded that, as the rotor is consistently loaded.

However, during turbulence I've been describing a much flatter descent, with less rotor loading between the roundout/initial flare and the full flare landing.
There is very little [additional] rotor loading from 6 feet to 0 feet, but much more reduction in AS. Thus the slight RRPM decay within the lower 300s.
Why this is so difficult to accept for some, I don't know. Perhaps I should film it as proof?



____________
Antony, I've played around with high-G base-final turns and noticed the increased RRPM.
However, I've found it to quickly dissipate and RRPM returns to normal values for the AS.
I don't recall any base-final overspeeded RRPM lasting into the roundout.

Since you didn't describe your flare as anything vigorus, nor mention any ballooning, it's hard for me to envision an oversped rotor from that flare.

But, if, now, you've come to believe that when you were at 4 feet and 10mph that you still had some overspeeded RRPM from either your turn or your flare,
which then began to decay causing an airflow reversal and sink, then I hope you're correct in your appraisal and have learned what you needed to learn.

However, since you're a gyro CFI, I admit to some surprise that this was something you didn't already know.

The other thing that surprised me was that you actually closed your eyes before impact.
As Bob Hoover was famous for saying,
"Fly the aircraft all the way into the crash."
I've actually commanded myself to "Aviate! " during dicey moments, and it helps.

_____
Thanks for everyone's participation; it's been enlightening, and my particular thanks to Antony for sharing his experience here.

Safe flying,
Kolibri
Wow! The trifecta, Kolibri has argued with and insulted three CFIs in a single post.

People wonder why more CFIs don’t share what they know on the Rotary Wing Forum. This is a perfect example of exactly why.

I doubt he has learned anything and he has wasted a lot of people’s valuable time.
 

Vance

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Kolibri;n1141231 said:
Not really, Vance.
Your truncated account here left out the most important thing: when the gust subsided you were at 20 feet, and you barely saved it with the prompt application of power.
Here is your own description from another thread:


(You'd already rounded out, thus above 20 feet.)
Let's be honest: Had that happened a couple of feet lower, or had the gust subsided more, you'd have dropped in hard.
What I summarized then I still believe: you were operating at that moment with very little margin for safety.
My impression is that you do so more often than you realize.


Safe flying,
Kolibri[/COLOR]
You are misconstruing a nonevent and pretending it was something that was dangerous.

I am not finished with my round out at 20 feet above the ground as you postulate.

The mental picture you have created based on your ignorance about landing a gyroplane is totally unrelated to the reality of the event.

Not everyone it trying to hide something.
 

Vance

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Kolibri;n1141231 said:
I am confident that nobody flying with one-eyed vision has the required depth perception to confidently and consistently roundout/initial flare at 6 feet.
For such a pilot, such would indeed probably be a bad idea, or even dangerous.

Regarding Vance's calling B.S. on me, I've GoPro videos of my training days in a Calidus rounding out at or below 6 feet.
I could do so then in my first several hours of gyro flying. (I was already a PP-ASEL, thus not an ab initio pilot.)
Only one time did my CFI Chris Lord ever reach for the stick, and that was when I experimented with rounding out at probably 3 feet.
I had already preceded his reaction with ample back stick, and he apologized for nearly adding to it as he thought we might have pancaked in.
I apologized for not giving him a heads up that I was going for a bit lower that time.

Just to make sure I wasn't misremembering things, I reviewed some of those landings. I was definitely rounding out in ground effect.
In fact, I watched the stick dip forward a tiny bit to compensate for the initial cushioning and not balloon up.
I.e., instead of using back stick to arrest descent in my roundout, I was using the gyro's ground effect to arrest my descent.
The video is also clear enough to carefully see the altimeter at roundout vs. touchdown.

So, anybody sufficiently confident that I do not have the skill set to land as I've described, should PM me to place a $$$$ wager on it.
I'll install my GoPro and gather some witnesses to also film it from the ground.


____
Thanks for everyone's participation; it's been enlightening, and my particular thanks to Antony for sharing his experience here.

Safe flying,
Kolibri[/COLOR]
This is typical of your "proof".

I doubt if any flight instructor would have you landing in gusting 25kt to 35kt winds so your review of your training video has no purpose.

I have already written that low time pilots tend to round out low because they have only flown in light winds and as soon as they fly in gusting winds above 25kts they quickly learn what a bad idea it is to round out low.

I have no idea why you appear to misunderstand the most basic things about flying a gyroplane, the effect of the wind and aviation decision making. There is clearly no point in me explaining it to you further.

Your continued snarky remarks about my monocular vision again reveal another of your misunderstandings.

If you imagine judging the timing of the round out and flare is done with binocular depth perception you are looking in the wrong place during your landings.

I fly with a statement of demonstrated ability and the FAA representative did not find anything deficient about my ability to execute simulated emergency landings.
 

WaspAir

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Kolibri;n1141243 said:
From my post 71, the green line illustrates what I've been trying to describe. It's a very flat slope (i.e., more level than not):


However, even if one did not descend so slightly, but kept level for a short distance at 2 feet while bleeding off airspeed,
how is that worse in turbulence than floating down at 14 degrees in a classic gyro descent?

Simple (and yet unaswered) question: when turbulence is present, is it generally stronger at 0-10 feet or at 20-50 feet?
That's been my central point in this entire thread.

During turbulence, I want to negate as much of it as possible by getting lower ASAP.
What turbulence remains will pose less risk because I've nearly no height left to drop from and my strong ground effect acts as cushion/spring against downdraft energy.
Where to start . . .

Here are two things for you to think about:

1. Ground effect does not provide a "cushion" to a gyroplane. It provides a reduction in induced drag which enhances performance when close to the surface. It is not an upward force to overcome downdrafts, and in no way acts like a spring to resist descent. The benefit you seek from it isn't real. It will not absorb any kinetic energy from dropping. Those who talk about a "cushion" of air don't understand the physics; ignore any sources that put it in such terms. There will simply be no advantage in your procedure from this phenomenon.

2. Tracks like the green line on your H-V diagram are sometimes drawn to show a preferred take-off profile. I suppose you can also draw a proposed path for approach on an HV diagram if you wish (I don't recall seeing it done before, because the HV diagram is, as I said above, intended to show risks of sudden engine failure in continuous high power operation, not atmospheric action on approach to landing). However, you must keep in mind what it shows and what it doesn't. The "slope" there is in units of foot of altitude lost per mph of airspeed, which is a very unnatural way of thinking for most pilots. There is no horizontal distance or time information presented, and no distance or time units can be inferred. That means it does not show glideslope information (slope of your path in space over the ground), and does not show how quickly speed is lost or gained (no g load information). The green line you drew could be flown in 2.5 seconds at a steady 2g deceleration or in 2.5 years with a very small g load and the line would look the same. The slope over the ground in the first case will be much steeper than in the other, but the line would not change. The rotor rpm will go very much higher in the first case and sit very, very stable in the second (at least until the last few months when you are below minimum level flight speed and can no longer hold to the line as shown). The runway distance used could be 100 feet with a 6 degree slope in the first, and 600,000 miles at barely more than 0 degrees in the other.
 

Kolibri

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Closing an eye, I'd not feel confident trying to roundout below 10 feet, no matter where I was looking.

I'm not trying to insult anyone, not even Vance. Buck up if you feel that way; trying to save lives here.


___________
I realize that no time component is present in my diagram.
I kept the illustration simple for clarity.



It is not an upward force to overcome downdrafts, and in no way acts like a spring to resist descent.
A wing generates lift by deflecting the oncoming airmass (relative wind) downward[SUP]. [/SUP]The deflected or "turned" flow of air creates a resultant force on the wing in the opposite direction (Newton's 3rd law). The resultant force is identified as lift. Flying close to a surface increases air pressure on the lower wing surface, nicknamed the "ram" or "cushion" effect, and thereby improves the aircraft lift-to-drag ratio. The lower/nearer the wing is with regards to the ground, the more pronounced the ground effect becomes.
https://en.wikipedia.org/wiki/Ground..._(aerodynamics)
Increasing air pressure on the lower wing surface sounds like an "upward force" to me.

Your description of the reduced drag is correct but incomplete (as are the FAA Handbooks), as you ignore the increased lift from actual ram pressure:


Lift: When you are in free space, the high pressure below your wing dissipates into the surrounding air.
When you're in ground effect, the high pressure below the wing encounters an incompressible solid, and therefore
cannot dissipate as quickly, causing higher pressure below the wing, and therefore more lift.

The "cushion-effect" explanation is actually quite correct. The pressure which lifts the airplane is not only created
by accelerating air downwards, but also by ram pressure. This effect disappears once the wing is far enough from the ground.
Here is the high pressure beneath a wing, in the air on the left, and in ground effect on the right.


ground effect on the right.png

Even if this were untrue, nobody has yet purported that turbulence is worse (or even identical) at 0-10 feet than 20-50 feet, and thus why it's so dangerous "down there".

Also, try to explain why a low-wing Piper lands easier in turbulence than a high-wing Cessna.
Even that few feet lower matters.
 

WaspAir

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Drop a brick on your foot on a windy day and notice just how well the increased ram air pressure as it gets low to your toes cushions the impact and gives an upward spring effect to protect your foot (the air it has been displacing as it falls must have nowhere to go now, right?).

Well, I guess the FAA and I have had it wrong all these years, and we should trust simplified laymen's explanations and homespun vocabulary from Wikipedia instead. It's a shame I wasted all those years of education.

If I thought you were really asking questions with an open mind and willingness to learn, I'd keep at this, but that doesn't seem to be the case.

To the reader:

Don't use Kolibri's suggested landing approach method.

See you on some other thread soon, everybody, bye-bye.
 
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