AR-1 N923DJ Texas 15-12-18

When they advance to gusty conditions and discover their approach has become less precision most learn quickly to stay well clear of the ground until most of their energy has been dissipated.
Then, in my opinion, they more risk pancaking in by staying "well clear of the ground until most of their energy has been dissipated".
Between roundout and flare I prefer the higher RRPM that comes from ample AS.
By the time my RRPM begins to decay, I'd rather be at 1-2 feet than 10+ feet.

Also, you can't have it both ways, Vance.
I.e., you can't claim that downdrafts either don't reach the ground or are slower near the ground,
and yet simultaneously profess that a higher roundout is safer (where wind shear is stronger).



Most people using your method for landing have an inadvertent touchdown at high speed and learn not to do that again without an accident report.
I'm not sure what is "at high speed" to you, but evidently I fly slower near the deck than you imagine.
Occasionally, when I was a rank newbie, I landed a bit hot, but since then my few inadvertent touchdowns are almost never at any unsafe (or even uncomfortable) groundspeeds.

On that note, I've seen many AutoGyro video landings of a noticeably high touchdown speed, including my Calidus training with Chris Lord (who did not teach very slow GS landings).
I land much more slowly than that, at a walking speed or less. Even a jogging speed, to me, borders on too fast.

With anything in life, a healthy balance is key. This takes maturity and experimentation to discover.
I hope that this thread will engender safer gyro flying.

Regards,
Kolibri
 
Kolibri;n1141167 said:
Then, in my opinion, they more risk pancaking in by staying "well clear of the ground until most of their energy has been dissipated".
Between roundout and flare I prefer the higher RRPM that comes from ample AS.
By the time my RRPM begins to decay, I'd rather be at 1-2 feet than 10+ feet.

Also, you can't have it both ways, Vance.
I.e., you can't claim that downdrafts either don't reach the ground or are slower near the ground,
and yet simultaneously profess that a higher roundout is safer (where wind shear is stronger).


I hope that this thread will engender safer gyro flying.

Regards,
Kolibri[/COLOR]

How much does your rotor rpm decay during your round out and flare before touchdown?

Please explain why your rotor rpm decays during round out and flare before touch down.


It is my observation that less precision is required in altitude control when one is further from the ground.

It appears you are still confused about wind direction and proximity to the ground.

Down drafts have nowhere to go so their speed becomes horizontal near the ground unless it is a collapsing thunderstorm.

The ground does tend to slow wind parallel to the ground because of friction.
 
Please explain why your rotor rpm decays during round out and flare before touch down.
<sigh> Because I am bleeding off AS between roundout and flare. (Doesn't everyone do that?)
Please get this clear in your mind: I do not touchdown at high speeds, meaning anything faster than a human's jogging speed.


It appears you are still confused about wind direction and proximity to the ground.
I am not confused about that, and never was. I'd have balled up my gyro long ago if I were.

Vance, I don't "get" you, and I've no more time to unravel your continual misperceptions.
We're apparently "wired" differently.
I feel that I've explained myself quite clearly in this thread, and will leave it at that.
 
The gyro I usually fly is very heavy with massive high inertia low-rpm blades (35 foot diameter, three blades, over 50 pounds each, less than 240 rpm in flight), so my typical experience may not reflect what happens with lighter craft, at least as to the size of the effects felt. I find that rotor rpm is not very sensitive to airspeed, but will vary a little with load. It is always my intention to land with the slowest ground speed possible, preferably zero. As I lose airspeed while landing, it is because I have applied aft cyclic to scrub forward speed, check descent rate, and flare, with the nose rising and the rotor disc inclined more to the rear. This action produces very slightly higher than +1g, which tends to increase rotor rpm. In practice, this means that as I lose airspeed while landing, if I notice any rpm change, it will be in the upward direction, because the effect of the loading increase is substantially bigger than the effect of airspeed loss.
 
Kolibri;n1141174 said:
<sigh> Because I am bleeding off AS between roundout and flare. (Doesn't everyone do that?)
Please get this clear in your mind: I do not touchdown at high speeds, meaning anything faster than a human's jogging speed.



I am not confused about that, and never was. I'd have balled up my gyro long ago if I were.

Vance, I don't "get" you, and I've no more time to unravel your continual misperceptions.
We're apparently "wired" differently.
I feel that I've explained myself quite clearly in this thread, and will leave it at that.

Everyone I know bleeds off airspeed during round out and flare in a gyroplane.

I have not flown a gyroplane where rotor rpm decays noticeably during round out and flare.

That is why I asked how much your rotor rpm decays during round out and flare.
 
The only thing I have to add to this argument between Vance and Kolibri is, with Vance's experience (2200 hours in rotorcraft) versus Kolibri's limited hours in rotorcraft, I'd have to go with Vance's experience over Kolibri's opinion!!!!!!!!!!!!!!!!!!
 
I have not flown a gyroplane where rotor rpm decays noticeably during round out and flare.
Whatever "noticeably" is . . .

A 20 RRPM difference at cruise RRPM (of, for example, from 360 to 340) wouldn't be important.
However, a reduction from 310 to 290 would be more important, since that is near (or at) minimum flight RRPM.

Think of it this way: if RRPM could not decay to just below flight RRPM, then you'd never be able to land. You'd hover. :wave:
Assuming a very slow touchdown GS, of course there is RRPM decay between roundout and flare.
It's the difference between barely flying and barely not.


__________
The only thing I have to add to this argument between Vance and Kolibri is, with Vance's experience (2200 hours in rotorcraft) versus Kolibri's limited hours in rotorcraft, I'd have to go with Vance's experience over Kolibri's opinion!!!!!!!!!!!!!!!!!!
a) Sometimes I consult with a renowned CFI with over 4000 hours before I post, and both of us have in the past been in common disagreement with Vance.
b) I've often times been correct even without such a confirming consultation.
c) Try different techniques for yourself. Don't take anyone else's opinion on it.

Regards,
Kolibri
 
I wish "Jim" would give his opinion on this subject here (rotary forum).
 
Kolibri;n1141178 said:
Whatever "noticeably" is . . .

A 20 RRPM difference at cruise RRPM (of, for example, from 360 to 340) wouldn't be important.
However, a reduction from 310 to 290 would be more important, since that is near (or at) minimum flight RRPM.

Think of it this way: if RRPM could not decay to just below flight RRPM, then you'd never be able to land. You'd hover. :wave:
Assuming a very slow touchdown GS, of course there is RRPM decay between roundout and flare.
It's the difference between barely flying and barely not.


__________

a) Sometimes I consult with a renowned CFI with over 4000 hours before I post, and both of us have in the past been in common disagreement with Vance.
b) I've often times been correct even without such a confirming consultation.
c) Try different techniques for yourself. Don't take anyone else's opinion on it.

Regards,
Kolibri

I would notice a twenty rotor rpm reduction.

It appears to me you have written with the agreement of your renowned CFI that during round out and flare your rotor rpm decreases twenty rotor rpm; is that correct Kolibri?

In my opinion something is wrong with your observation or your gyroplane.

I am loading the rotor when I round out and flare.

A rotor responds to increased load with increased rotor rpm.

I feel you and your renowned CFI need to do some research on what affects rotor rpm in a gyroplane because based on or past interactions; you won't believe me.

I feel understanding how a rotor responds is an important part of gyroplane aerodynamics and knowledge any gyroplane pilot should possess.
 
It appears to me you have written with the agreement of your renowned CFI that during round out and flare you rotor rpm decreases twenty rotor rpm; is that correct Kolibri?
Nope, didn't write that.
I wrote:
Between roundout and flare I prefer the higher RRPM that comes from ample AS.
By the time my RRPM begins to decay, I'd rather be at 1-2 feet than 10+ feet.

The "By the time my RRPM begins to decay" is obviously contextual to the interval mentioned, between roundout and flare.
That's all I've been talking about. I.e., to prevent pancaking in from too high.



I am loading the rotor when I round out and flare.
Sure, from each event there is a brief increase of RRPM because of newly loading up the rotor, but then after each event you see a decay as AS is decreased for landing.
As proven above, I was clearly writing about the time between roundout and flare.


You, however, in your constant eagerness to catch me in an error, you yet again failed to comprehend my clear English.
"between roundout and flare" meant just that.
Crowing victory, you then erroneously tried to attach this alleged error also to my CFI.
 
Kolibri;n1141181 said:
Nope, didn't write that.
I wrote:


The "By the time my RRPM begins to decay" is obviously contextual to the interval mentioned, between roundout and flare.
That's all I've been talking about. I.e., to prevent pancaking in from too high.




Sure, from each event there is a brief increase of RRPM because of newly loading up the rotor, but then after each event you see a decay as AS is decreased for landing.
As proven above, I was clearly writing about the time between roundout and flare.


You, however, in your constant eagerness to catch me in an error, you yet again failed to comprehend my clear English.
"between roundout and flare" meant just that.
Crowing victory, you then erroneously tried to attach this alleged error also to my CFI.

How long is the interval between your round out and your flare where your rotor rpm decreases Kolibri?

I mentioned your renowned CFI because you did; stating he was in agreement.

I was taught and I teach that the flare is the end of the round out. In my opinion based on my observation there is no gap between the round out and the flare where rotor rpm decreases below the rotor rpm at the approach speed.

I am not able to use the rotor to slow down my gyroplane and arrest my descent without loading it. This is what I do during the round out and flare.

I often wonder what gaps in your knowledge cause you to draw such strange conclusions. Now I know one of many is you believe the rotor slows between the round out and the flare. This is simply absurd no matter how you parse it.
 
The term "round out" is not universally used, actually. It's often called "flare" and then "full-flare" for landing.

When you write "
round out" you're speaking of the normal landing technique of initially flaring at 10-20 feet.
In that maneuver, you are settling more vertically and may not see any RRPM decay (unless there is loss of lift) because you are keeping the rotor loaded.

But that is not the maneuver I've been talking about in this thread.

What I've been describing is a technique used during turbulence: i.e., rounding out (or
"flaring" according to the FAA-H-8083-21 - Rotorcraft Handbook) low enough to be within the rotorwash.
Meaning, there is very little altitude to settle from, as insurance against strong downdrafts, and the rotorwash will help cushion a premature touchdown.

This would seem a very difficult technique to master without depth perception. Those with significant visual impairment probably should not attempt it.

The alleged "
gaps" in my knowledge, in this instance, are gaps in your comprehension of what I wrote and its context.
It's happened many times before. Please, if you can, cease and desist -- thanks.



my post #74 --
Today, 05:04 PM ___________________________________________

1) By "within the rotorwash", are you talking about carrying extra speed until deep into ground effect?
2) Are you describing a brief period of level flight low and along the runway between an initial roundout and a later flare?
3) Do you expect to float along in ground effect before a final arrival?
WaspAir:
1) Yes, but it doesn't necessarily have to be "
extra speed", but a normal roundout AS, just executed lower.
Actual desired AS depends upon the conditions. One may desire to add half the gust factor, for example.
The purpose is to be able to penetrate a morass of vortices more horizontally than vertically, and getting low to the runway sooner.

2) Yes, assuming the lower roundout/initial flare I've been discussing.

3) While there is rotorwash, there is some float.



I have trouble envisioning any advisable maneuver that would permit rotor rpm to decrease near the end of a landing approach.
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.



__________
In my opinion close to the ground at speed is not the place to be with reduced ability to manage altitude precisely.
Well, since according to you Vance, downdrafts are less severe at lower altitudes (and nonexistent just a few feet from the runway), how is altitude management ability more reduced at 2 feet vs. 20 feet?


In my opinion Antony was not smacked into the ground from a down draft because down drafts have nowhere to go
as they reach the ground and lose their downward velocity well above the surface unless it is a collapsing thunderstorm or a microburst.
You've claimed many times that downdrafts do not reach the ground unless on the order of microburst severity.
I continue to be amazed at this.
Of course they lose some velocity along the way, but that doesn't automatically prevent them from reaching the ground at all if their initial energy was sufficient.

Nowhere to go? Sure, they do: radially, with whatever energy is left.
To claim otherwise is like saying that a ball cannot be rolled into a wall because the ball has "
nowhere to go".






5 Jan 2019, 01:03 PM in what would have been post #77 (continued forum glitch) ___________________________________

First off, neither I nor my CFI believe or have claimed that RRPM decays at the moment of a roundout/initial flare or a full-flare.
I never wrote that it did.
Vance misinterpreted it that way.



__________
Why would you find it disconcerting coming in at a moderately higher airspeed (say half the gust spread) in a gyro, if this would provide some protection from changes in lift close to the ground? With stronger gustier wind conditions this should not result in significantly increased groundspeed. Add to this the ability to effectively use the rotor as a brake on the aircraft during touchdown, I'm still a little puzzled as to why in a gyro one should not follow a similar approach as one would a FW to build in a safety factor.
loftus, you're asking the right questions. Glad to see it.
We gyro pilots can scrub off excess AS (and thus GS) any time we like.
We also enjoy powerful rotorwash as a cushion against downdrafts.
Why not use them both?



__________
I find it disconcerting to be coming in at high speed close to the ground.
thomasant, I agree, so maybe we're not seeing eye to eye about what is "high speed" close to the runway.

I've been thinking about a rule of thumb for this. Perhaps 1 foot off the deck for every 10mph of groundspeed?
(I'm speaking of groundspeed because of the imminence of landing, or possibility of being smacked down by wind shear. I'm not conflating GS with AS.)

So, say, after 60mph GS roundout/initial flare at about 6 feet, adjust power/stick to reach 50mph@5', 40mph@4', 30mph@3', and 20mph@2'.
Along the way, you will see a slight decay in RRPM, although still in the lower 300s (using my Sport Rotored RAF as an example) and in the flight RRPM range.

Note: the above is simply a thought experiment to roughly illustrate what I've been trying to describe.
Please resist the urge to peck it death as if I'm spouting POH doctrine.

Antony, you reported having 10mph GS at 4 feet, which, IMO, was a bit too high for that speed. Or, a bit too slow for that altitude.
I'd have felt somewhat vulnerable to downdrafts during those numbers.

Regarding that, I'm interested to see how Vance will try to reconcile two of his contradictory statements:


"In my opinion Antony was not smacked into the ground from a down draft because down drafts have nowhere to go as they reach the ground
and lose their downward velocity well above the surface unless it is a collapsing thunderstorm or a microburst
."

and:

"My feeling is that a wind shear started the challenge
[at 4 feet AGL] and several other factors exacerbated the event."

What, then, is "well above the surface"? According to Vance, it must below 4 feet.



___________
In a gyro, there is no collective and hence no direct control in dropping RRPM, and if there is a rapid rise in RRPM close to the ground,
it is possible to get into the situation described by Birdy/Doug and even though there may not be a hover, the airflow reversal effects can be pretty drastic.
With adequate AS, one simply pitches down and increases power to avoid the hover. Keep flying. Keep moving forward at the chosen low altitude.
Then gradually reduce power with gradual aft stick to time the moment for a nice full-flare and 0-5 mph touchdown.

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.


___________________
From the
FAA-H-8083-21 - Rotorcraft Handbook, page 19-3 is the HEIGHT vs. VELOCITY FOR SAFE LANDING for gyros.
This is a general diagram for zero wind conditions, without turbulence. One should avoid continuous flight within the hatched area.

My CFI and I consider this insufficiently conservative (especially at 12' and 0mph AS -- kerplop!).
We prefer a lower and flatter approach, especially during turbulence.

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.)



Kolibri's notation of the FAA Gyro height vs. velocity diagram-2.png


I've added two colored lines.
The
green line signifies my thought experiment description of landing in turbulence with a 6' AGL roundout/initial flare at 60mph, decreasing 1' per 10mph thereafter.

The
blueline shows a steepened slope, yet still flatter than the classic vertical descent. A 22' roundout at 60mph, and then decreasing about 2' per 10mph.
This is closer to the hatched area, and in my opinion is as steep as is prudent during turbulence.

I hope this diagram helps explain why I and my CFI do not prefer vertical descents through very dirty/energetic air.

Although Antony's 4' AGL and 10mph was outside the hatched area, he was apparently not high enough or fast enough to power out of a downdraft.
And, more to my point, he was not low enough to sufficiently lessen the impact from that downdraft.
This is my take on the incident with what details he's posted, and my comments are neutrally offered without criticism.

Regards,
Kolibri
 
Perhaps you can help me with my comprehension, because I am not following. I have no visual impairment, but I have trouble envisioning any advisable maneuver that would permit rotor rpm to decrease near the end of a landing approach.
By "within the rotorwash", are you talking about carrying extra speed until deep into ground effect?
Are you describing a brief period of level flight low and along the runway between an initial roundout and a later flare?
Do you expect to float along in ground effect before a final arrival?
 
To summarize my thoughts on this thread.

In my opinion Antony was not smacked into the ground from a down draft because down drafts have nowhere to go as they reach the ground and lose their downward velocity well above the surface unless it is a collapsing thunderstorm or a microburst.

I don't know what did happen.

I will not be changing my landing technique in gusting winds. The only adjustment I make in gusting winds is to come in with a little power to give me more rudder authority incase I lose airspeed from a wind shear or need rudder to be aligned with my direction of travel. The engine will also respond to an addition of power more quickly above idle.

In my opinion coming in faster and beginning the flare or round out lower for landing a gyroplane in gusting conditions is a very bad idea.

Indicated airspeed may vary considerably because of gusting winds during the approach making precise control of altitude more difficult. Fifteen knots of wind shear is common where I fly, twenty knots is not unusual.

According to Antony; Anahuac has similar conditions.

It is not unusual for wind shear to change directions 180 degrees.

A gust that increases indicated airspeed may cause a gyroplane to balloon up and a twenty knot loss of indicated airspeed during the round out may cause a rapid sink.

In my opinion close to the ground at speed is not the place to be with reduced ability to manage altitude precisely.

There are several NTSB reports from inadvertently striking the ground at speed in a gyroplane.

In my opinion this is not a semantics debate. This is about reality and how someone chooses to fly.

Every gyroplane accident diminishes all gyroplane pilots and makes getting into gyroplanes more difficult.
 
1) By "within the rotorwash", are you talking about carrying extra speed until deep into ground effect?
2) Are you describing a brief period of level flight low and along the runway between an initial roundout and a later flare?
3) Do you expect to float along in ground effect before a final arrival?
WaspAir:
1) Yes, but it doesn't necessarily have to be "
extra speed", but a normal roundout AS, just executed lower.
Actual desired AS depends upon the conditions. One may desire to add half the gust factor, for example.
The purpose is to be able to penetrate a morass of vortices more horizontally than vertically, and getting low to the runway sooner.

2) Yes, assuming the lower roundout/initial flare I've been discussing.

3) While there is rotorwash, there is some float.



I have trouble envisioning any advisable maneuver that would permit rotor rpm to decrease near the end of a landing approach.

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.



__________
In my opinion close to the ground at speed is not the place to be with reduced ability to manage altitude precisely.
Well, since according to you Vance, downdrafts are less severe at lower altitudes (and nonexistent just a few feet from the runway), how is altitude management ability more reduced at 2 feet vs. 20 feet?


In my opinion Antony was not smacked into the ground from a down draft because down drafts have nowhere to go
as they reach the ground and lose their downward velocity well above the surface unless it is a collapsing thunderstorm or a microburst.
You've claimed many times that downdrafts do not reach the ground unless on the order of microburst severity.
I continue to be amazed at this.
Of course they lose some velocity along the way, but that doesn't automatically prevent them from reaching the ground at all if their initial energy was sufficient.

Nowhere to go? Sure, they do: radially, with whatever energy is left.
To claim otherwise is like saying that a ball cannot be rolled into a wall because the ball has "
nowhere to go".
 
The Rotor RPM (RRPM) during a flare should go a bit higher. As far as the rotor is concerned, it thinks the weight of the aircraft has gone higher. You could see 1.1 to 1.2 G during a flare and you do.
Another simple way to see it is that inflow air velocity or volume has gone higher as flare is executed. We are opening the rotor disc to see or eat more air.
Many people also cite Coriolis effect but for most modern gyroplane rotors, this effect is negligible.
I would be a bit worried if a gyroplane rotor RPM went lower instead of a bit higher when starting a flare.

I don't know which 4000 hour CFI agrees that rotor RPM will definitely go lower as flare is executed but let them know that vector diagrams and Nick Lappos completely disagree with them. Let me know how with vector diagrams or by proof in video your RRPM go lower as you start a flare. Something does not add up here.
 
Some thoughts of mine:

Vance described his landing sequence, that is exactly how I teach students. I find it disconcerting to be coming in at high speed close to the ground.
What I do during gusty winds is keep the rudder effective by some increased engine RPM and be prepared to go round with power as required.

Rotor RPM always increases in flare and high G moves. In a heli, this could easily be controlled by the collective. In the Lama, during flares, the goal was to try and increase rotor RPM to get a better cushion effect when pulling collective for touch down.

In a gyro, there is no collective and hence no direct control in dropping RRPM, and if there is a rapid rise in RRPM close to the ground, it is possible to get into the situation described by Birdy/Doug and even though there may not be a hover, the airflow reversal effects can be pretty drastic. It would be good if this phenomenon is better understood and taught.
 
thomasant;n1141193 said:
Some thoughts of mine:

Vance described his landing sequence, that is exactly how I teach students. I find it disconcerting to be coming in at high speed close to the ground.
What I do during gusty winds is keep the rudder effective by some increased engine RPM and be prepared to go round with power as required.

Rotor RPM always increases in flare and high G moves. In a heli, this could easily be controlled by the collective. In the Lama, during flares, the goal was to try and increase rotor RPM to get a better cushion effect when pulling collective for touch down.

In a gyro, there is no collective and hence no direct control in dropping RRPM, and if there is a rapid rise in RRPM close to the ground, it is possible to get into the situation described by Birdy/Doug and even though there may not be a hover, the airflow reversal effects can be pretty drastic. It would be good if this phenomenon is better understood and taught.

Why would you find it disconcerting coming in at a moderately higher airspeed (say half the gust spread) in a gyro, if this would provide some protection from changes in lift close to the ground? With stronger gustier wind conditions this should not result in significantly increased groundspeed. Add to this the ability to effectively use the rotor as a brake on the aircraft during touchdown, I'm still a little puzzled as to why in a gyro one should not follow a similar approach as one would a FW to build in a safety factor.
 
First off, neither I nor my CFI believe or have claimed that RRPM decays at the moment of a roundout/initial flare or a full-flare.
I never wrote that it did.
Vance misinterpreted it that way.



__________
Why would you find it disconcerting coming in at a moderately higher airspeed (say half the gust spread) in a gyro, if this would provide some protection from changes in lift close to the ground? With stronger gustier wind conditions this should not result in significantly increased groundspeed. Add to this the ability to effectively use the rotor as a brake on the aircraft during touchdown, I'm still a little puzzled as to why in a gyro one should not follow a similar approach as one would a FW to build in a safety factor.
loftus, you're asking the right questions. Glad to see it.
We gyro pilots can scrub off excess AS (and thus GS) any time we like.
We also enjoy powerful rotorwash as a cushion.
Why not use them both?



__________
I find it disconcerting to be coming in at high speed close to the ground.
thomasant, I agree, so maybe we're not seeing eye to eye about what is "high speed" close to the runway.

I've been thinking about a rule of thumb for this. Perhaps 1 foot off the deck for every 10mph of groundspeed?
(I'm speaking of groundspeed because of the imminence of landing, or possibility of being smacked down by wind shear. I'm not conflating GS with AS.)

So, say, after 60mph GS roundout/initial flare at about 6 feet, adjust power/stick to reach 50mph@5', 40mph@4', 30mph@3', and 20mph@2'.
Along the way, you will see a slight decay in RRPM, although still in the lower 300s (using my Sport Rotored RAF as an example) and in the flight RRPM range.

Note: the above is simply a thought experiment to roughly illustrate what I've been trying to describe.
Please resist the urge to peck it death as if I'm spouting POH doctrine.

Antony, you reported having 10mph GS at 4 feet, which, IMO, was a bit too high for that speed. Or, a bit too slow for that altitude.
I'd have felt somewhat vulnerable to downdrafts during those numbers.

Regarding that, I'm interested to see how Vance will try to reconcile two of his contradictory statements:


"In my opinion Antony was not smacked into the ground from a down draft because down drafts have nowhere to go as they reach the ground
and lose their downward velocity well above the surface unless it is a collapsing thunderstorm or a microburst
."

and:

"My feeling is that a wind shear started the challenge
[at 4 feet AGL] and several other factors exacerbated the event."

What, then, is "well above the surface"? 3 feet? 2 feet? According to Vance, it's not as low as 4 feet.



___________
In a gyro, there is no collective and hence no direct control in dropping RRPM, and if there is a rapid rise in RRPM close to the ground,
it is possible to get into the situation described by Birdy/Doug and even though there may not be a hover, the airflow reversal effects can be pretty drastic.
With adequate AS, one simply pitches down and increases power to avoid the hover. Keep flying. Keep moving forward at the chosen low altitude.
Then gradually reduce power with gradual aft stick to time the moment for a nice full-flare and 0-5 mph touchdown.

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, then getting to 1-2 feet in preparation for 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.

Regards,
Kolibri
 
Fixed wing aircraft always land with significant airspeed (with only speed and altitude storing energy), have a stall condition to avoid before touchdown, and must shed kinetic energy with drag and wheel-braking on the rollout. That stall avoidance is where much of the safety margin comes from. There is no corresponding benefit for an aircraft that has no stall, stores additional energy in the rotor, and is best touched down at the lowest speed possible, shedding most of the energy in the air. (As Igor Sikorsky said, it's better to stop and then land, than to land and then stop.) I always use the rotor as a brake at touchdown, but don't find an advantage in a need to do more braking arising from extra airspeed. I agree that the extra energy you propose isn't huge, but it also isn't terribly helpful.
What I typically do in strong wind conditions is change my pattern shape, with a base leg closer in. In case of a power failure, penetrating against a wind in a low glide ratio gyroplane is pretty difficult, and can leave one well short of the intended landing spot. The same principle is true of most fixed wing aircraft, but in my experience, they typically penetrate wind on final much better with a little extra speed than a gyro will.
 
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