Confused about crosswinds.

[All_In]

Thank you Vance I've learned from this thread!

[Penguin]

Thanks, Vance.
A good explanation of rotor reversal. New to me.
But I'm surprised that you taxi with the stick back.
I was taught to get the disk flat and leave it there once I got whoa-ed up.
About the only deviation is to accommodate any cross-winds.

[Vance]

Hello Larry

I read what I wrote looking through your window and I can see why you thought I taxi with the rotor back.

It was a sloppy use of language.

When I want to take off again if the rotor rpm is still over 120 then I can come full back without striking the vertical stabilizer or rudder and roll forward. At 185 rotor RPM I can give her full throttle and accelerate without flapping the blades.

I do this to accelerate the rotor for takeoff.

If I am done flying I push the stick full forward and began to stop the rotor. When I am below 75 rotor RPM I apply the rotor brake and increase the pressure when she squeaks so that the rotor stops front to back.

I taxi around the airport with the disk full forward or with the rotor condom installed.

The rotor blades are nearly unmanageable when they stop across the airframe and the winds are over about 15 kts. I don’t like to put that much pressure on my control system.

Taxi was a poor choice of words to describe the rolling while waiting to accelerate.

Thank you, Vance

[Penguin]

Gotcha!
That makes more sense.

[ferranrosello]

Vance, it is impossible to say an specific lateral input in the ciclic to compensate a crosswind in Take Off or landing. You need to watch what is going on and to correct in accordance to that.

The gyrocopters have the problem that they start to fly much sooner than a FW, and at this low speeds the crosswind component is much more notable. But the rotors are much more powerful than fixed wings, and you will have absolute control authority since the beginning. Because of that at the beginning of the Take Off roll you will need more lateral input in your ciclic that one you have buidl up some speed.

So, if you prerotate your rotor in a crosswind you will need a good lateral ciclic input until avoiding the flapping. This input will be fadding during prerotation. At the end you will have about 3 cm of ciclic lateral input in strong cross winds. Start the take off with this input and control your input accordingly with the circunstances: fly...

If you feel a bouncing side to side at the very begining of the take off, when your front wheel is still on the ground, is because your initial lateral ciclic input of 3 cm is too much, reduce the lateral ciclic until the bounce dissappears. Once the front wheel is flying: fly...:

The pedals drive the yaw: keep the nose in the runway heading using the appropiate pedal input.

The lateral ciclic drives the side movements of the gyro (not the heading). If your gyro is moving to the right: increase you left ciclic input slowly until the movement disappears. If your gyro is moving leftwards, then increase your right ciclic.

Once airborne, let the gyro fly into the wind, and fly with an adequate crab angle.

This is the good way to manage crosswind. But you needn't to be landing or taking off to practice it. The only thing you need is a road or other long and straight reference, a safe flying altitude and a good cross wind component against the straight reference.

Then try to fly your gyro at normal approach speed above the road with the gyro in the road's heading, and compensate the lateral movements with the appropiate lateral ciclic inputs. It is exactly the same exercise that landing or taking off in crosswinds.

Once you are able to control this at the normal speed, then try it at lower and lower speeds, you will see that you need more crossed control inputs.

Finally make your approaches in this way whenever you find crosswinds. You will feel how the required crossed controls reduces when you are closed to the ground (the wind there is alway weaker.).

I have read you article about the air festival. It is very good.

Ferran

[Doug Riley]

Vance, I've never heard of a gyro capsizing INTO the wind because the pilot over-compensated for crosswind. Moreover, an incipient capsize to windward is self-limiting: as the gyro tips toward the wind, the disk AOA goes down. The opposite happens in a capsize to leeward: it's self-accelerating as the disk exposes more and more of its bottom surface to the wind.

All this leads me to believe that it is difficult, if not impossible, to use too much side-stick during the "reversal" phase, with much less than flight RRPM.

I can't give you a number in degrees, since RRPM as well as the wind speed are part of the equation. I use a generous amount of windward side-stick, at least half of the available travel (the total being about ten degrees either side of neutral on Bensen-configured machines).

[Vance]

Hello Ferran,

That is wonderfully specific advice covering many stages of the learning process dealing with crosswinds.

It is well written and in my opinion good advice.

I have read of several rollovers and talked to two pilots who had a rollover in an autogiro.

The two I talked to were both on landing.

A rollover seems to be a somewhat un-quantified autogiro demon and I wonder how close I am to trouble when I take off in gusting cross wind conditions over my current limit of 30kts with a 10kt gust spread. My crosswind component limit of 10kts is not based on a particular experience. 15kts may be a more reasonable limit based on my recent experience.

On one of my flight reviews, not the last one, my instructor’s primary criticism was being in too big a hurry to take off and rushing my exit from the runway on landing so I am trying to explore this deficiency in my flying. I begin my pre-rotation as I cross the hold short line with the prevailing wind often at 90 degrees to the aircraft and am usually at 100 RRPM before I get to the centerline. He taught me to wait till I was pointed into the wind to start my pre-rotation and not taxi any further than the other side of the hold short line before spooling down. I had discounted these instructions as something only students needed to do.

I feel the gust spread combined with the crosswind component is the more relevant limitation but the direction of the gusts is often not reported so I find it hard to develop a go-no go limit for cross wind gusts. The gusts at some of the coastal airports near the hills are often as much as 30 degrees off of the prevailing wind and swirls are not uncommon.

I cannot control what the wind will be at my destination airport so a landing limit is less useful than a takeoff limit. Landing into a strong steady wind has not proved challenging although gusts misaligned with the prevailing wind have produced some learning moments.

I practice your suggested ground reference maneuver every time I fly a left pattern at SMX because I have some things lined up for my down wind.

I also often fly the full length to the runway (8,004 feet) at less than 25 feet to practice runway alignment. ATC at SMX is very generous with the things they approve for me.

You bring up another point that I still feel uneasy about.

When lifting off with a large crosswind component I usually keep her on the ground a little longer and then let her yaw into the wind as we leap into the air. In gusting conditions this could potentially lead to a misaligned touchdown.

It appears to me that if I keep her aligned with the runway the yaw compared to the relative wind slows her climb. The Predator always seems to climb slowly initially and then solo the climb increases to 1,100 feet per minute at 60kts on most days.

I feel this slow initial climb in close proximity to the ground is what might be described as the shaded part of her height/velocity curve although I regularly practice engine outs on takeoff in this altitude range without incident.

The question for me becomes should I keep her aligned with the runway and slow her climb or let her yaw to climb out quickly?

Thank you for the kind words on my air festival article. Which air festival article are you speaking of?

Thank you again for you thoughtful response, Vance

[Vance]

You have turned on the light of comprehension for me and I am now confused on a higher level.

Just to make sure I have understood I will try to paraphrase the knowledge and advice you have so generously offered.

Too much tilt into the wind is a non destructive pilot error that will only delay the rotor reversal.

Too little tilt into the wind has the potential to create an expensive learning moment.

I love simple answers to questions I have made complex by over thinking.

I am not in a hurry to get the rotor back up to speed with our 8,000 foot runway so a little extra distance to get the rotor going is simply not very important.

If I am somewhere it is important I will simply taxi back.

Thank you, Vance

[ferranrosello]

Vance, thank you for your comments, this was the article:
Flying in the Thunder Over the Valley Air Show
Vance, thank you for your comments, this was the article:
Flying in the Thunder Over the Valley Air Show
By Vance Breese, EAA 705840, for Light Plane World

A couple of comments.

"When lifting off with a large crosswind component I usually keep her on the ground a little longer and then let her yaw into the wind as we leap into the air. In gusting conditions this could potentially lead to a misaligned touchdown."

I think that this is the best way. But keep her in the ground a little longer with the nose wheel flying (the lower the wheel over the ground the better). When you yaw into the air and adopt a crab angle, you are releasing a lot of drag, which will rocket your gyro climbing ability.
“It appears to me that if I keep her aligned with the runway the yaw compared to the relative wind slows her climb. The Predator always seems to climb slowly initially and then solo the climb increases to 1,100 feet per minute at 60kts on most days.”
That is normal, just because of the drag you are releasing. Slip flying requires much more drag, that it is much more power. And the ability to climb is just the excess of power we are using above the required for leveled flight. In the very moment in which you are crabbing your gyro is like a sudden neat increase in the power you are using for climbing which accelerates you to normal climbing rates. Furthermore, because you have took off at an higher speed, you will be much close to the minimum power required speed what will increase your climbing even more.
So the answer is clear: let her yaw. After doing that you will be in a much safer position.
Ferran

[GyrOZprey]

GREAT thread - I love to read & learn from others experiences & relate these scenarios to my windy lessons in the spring!

[Vance]

Thank you Ferran,

I will be flying in the Thunder Over the Valley air show again in two weeks.

Dan, the editor of Light Plane World was the one who arranged the forum at AirVenture at Oshkosh, Wisconsin.

I am trying to learn to write so my wife and I can create a picture book of our gyroplane adventures.

Ferran, I am impressed with how well you write in other than your native language particularly about something that requires precision. In my opinion your challenge is exacerbated because you have to first figure out what I am trying to say about something I don’t understand.

My Forum at AirVenture and one I did at Mentone was about the history of the Autogiro and I asked people to imagine that they lived in a nice upscale neighborhood in 1912 and they had 17 year old Juan de la Cierva next store building aircraft in his garage with his two friends.

Most of us have trouble imagining what it must have been like in Spain before the revolution; you probably have a better sense of that.

Dan has asked me to write this in an article for Light Plane World and I have commenced work on it.

Back to the topic of the thread.

The answer is not so clear to me. If the wind is gusting, particularly if the gusts are out of line with the prevailing wind and runway I may get put back down on the ground without enough time to correct the misalignment with the runway. I feel this could lead to an expensive learning moment.

I feel this hazard is compounded if I have a heavy passenger that slows our climb out.

I ran into this challenge at El Mirage when I was giving rides. By mid day the density altitude had reached over 6,000 feet and some of my passengers were the far side of 250 pounds (114 kilos). I was trying not to work the pre-rotator too hard because I gave 45 rides in one day and I did not want to run down my battery or overheat the starter that The Predator uses for prerotation. The lift off could best be described as casual. More than once we achieved lift off and a gust or a rotor from the nearby hills would set us back down so I would maintain runway alignment until we had reached around three feet (1 meter) above ground level.

For those who think that is silly and you can take off in any direction at El Mirage; in my experience the wind direction can change dramatically as you approach the large hill near the edge of the dry lake. I wanted to take off in a relatively straight line so our path was more predictable for other traffic on the lakebed. Often before the end of the short ride the wind would have changed direction and we would land in a different direction than we took off. When I would take off and land I would call out the heading as “142 Mike Golf, lining up for takeoff on runway 27” if our heading was 270 degrees.

Thank you, Vance

[Vance]

Originally Posted by GyrOZprey

GREAT thread - I love to read & learn from others experiences & relate these scenarios to my windy lessons in the spring!

Hello Chris, I am pleased you are learning along with me on this thread. Please understand that my wind limit was 5kts with a 3kt crosswind component until I had over 20 hours as pilot in command.

Gyroplanes handle winds very well. New pilots may find themselves challenged with the rapidly changing windy environment and the way the rudder loses effectiveness by the square of the decrease in speed.

In my experience an elegant landing in windy conditions is preceded by a lot of good choices and a harmony of rudder, throttle and cyclic inputs. There have been a lot of rollovers on landing by low time gyroplane pilots.

In other words to all you less than 500 hour pilots please don’t imagine because you have read this thread that you can manage big winds and cross wind landings and take offs.

In addition please don’t imagine that because it worked once that you know how to do it. I feel there is a certain element of luck in the timing of the gusts and even my luck is not always good. As a low time pilot I accomplished some landings that in my opinion were well beyond my capability. The design of The Predator and good fortune were what saved us, not my piloting skill. I have since had less good luck but combined with what I have learned the results were still inexpensive.


A tangent:

I am taking the mechanic who was the primary on my annual condition inspection on a flight up to San Luis Obispo for lunch today so I need to get to work so I can manage that in a timely.

He is going to take time off of work so he can experience a flight with the minimum amount of fog. I feel fortunate to have an IA who likes and knows something about gyroplanes.

Phil, the boss at Costal Valley Aviation is very nice about helping but he still spits the P when he says exPerimental. Just yesterday as we were trying to track down an ignition noise in the radio he said; “your P lead wiring is good for an exPerimental but your switches belong on a tractor, not an aircraft.”

Thank you, Vance

[cburg]

As a low-time gyro pilot and high-time WSC & FW pilot I’m very interested in learning more about crosswind techniques in general and roll-overs in particular. I feel like the more I learn…the less I know.

My initial training in a Sparrow Hawk was accomplished strictly in strong cross-wind conditions, by choice because I was deciding whether or not to get into gyros (for more utility and a smoother ride in rough air).

I found crosswind landings very easy but take-offs a little harder. I typically drifted off center during the spool-up phase after the nose-light phase during a take-off run….despite what seemed to be a lot of side stick (and rudder input)….which turned out to be too much after lift-off.

I’m easing into x-winds in my Monarch and want to avoid problems (feels like a higher CG than most trikes). Any roll-over avoidance advice is greatly appreciated.

Chuck

[Vance]

Hello Chuck,

I too had much of my training in a Sparrow Hawk.

I felt the linked steering made getting enough rudder in during takeoff in a cross wind more challenging.

As I recall your Monarch has linked steering too.

Larry Neal may have some suggestions on the best way to manage a cross wind takeoff.

Landing in a steady crosswind is easy, just point her into the wind once you learn to manage you touchdown point. Gusts can be problematic and this is where experience helps.

The gyroplane I fly, The Predator has a free castering nose wheel and steers with differential braking so rudder input during takeoff is not an issue. She still tends to snap into the wind when I lift off but holding the centerline just before liftoff is much easier for me than it was in the SparrowHawk.

I caution you to work your wind limit up slowly because in my opinion it is about a harmony of control inputs that comes from experience rather than an intellectual understanding of the process.

Each landing is different and this inconsistent environment makes the learning process more difficult for me.

I have over 3,000 landings in The Predator and I still learn with each landing. My desire to learn to take off in higher gusting crosswinds is primarily driven by flying in air shows. It is my compelling reason to takeoff and fly in less than ideal conditions.

It is my observation that most roll overs in a gyroplane happen on landing. It appears to me that the wind gets under the rotor just like the wind getting under the wing of your tricycle. In my opinion the center of gravity has less to do with it than rotor management. As my instructor would say; “the flight is not over until the rotor is stopped!”

It is easy to misjudge the wind direction and I make it a point to touch down near a wind sock. There are five windsocks that I watch at SMX and it is not unusual for each of them to indicate a different wind direction.

I go on high alert if I see the wind sock straight out and twitching through thirty degrees.

At SMX like most airports the wind sock is calibrated to be fully erect at 15kts of wind.

I have found the ATIS wind direction can be off by as much as 30 degrees and even a wind check while landing does not identify shear and it is only the direction at one place on the aerodrome.

All the best on your gyroplane adventure, Vance.

[cburg]

Originally Posted by Vance

Hello Chuck,

It is my observation that most roll overs in a gyroplane happen on landing. It appears to me that the wind gets under the rotor just like the wind getting under the wing of your tricycle.

.

Vance,

That’s good to know. Us trike pilots are well trained to keep the upwind tip down. They are much more likely to roll-over if you catch the crosswind…even an attempt (at this late point) to pull it back down will precipitate a roll-over. Instead, all you can do is turn away as you bring the tip back down…carefully. Flying a FIB (Flying Inflatable Boat – trike on a boat) it will absolutely force you to learn this. They say there are two types of FIB pilots those that have rolled them over and those that will.

It appears that Gyros are the same as a trike in that a rapid/late attempt to lower the upwind rotor catching too much x-wind could leverage the undercarriage the opposite direction precipitating the roll-over.

Do I have this right?

Chuck