Some wind and decision making lessons.

[Vance]

Saturday at El Mirage Dry Lake I wanted to fly to Sothern California Logistics (VCV) for gas so I could get an early start home on Sunday before the wind came up.

The weather challenges on the flight from SMX to El Mirage Dry Lake are wind and turbulence in the high desert in the afternoon and fog along the coast in the morning. Heading home is always easier.

Friday a client asked me to take his six foot three friend for a flight so I invited him along for Saturday’s flight. He has about 70 hours in a Cessna 172.

I checked the weather at flight service and AIRMET Tango was in effect with peak winds of 50kts expected later in the day. If I was going to VCV I wanted to do it now.

AIRMET Tango describes moderate turbulence; sustained surface winds of 30 knots or greater; and non-convective, low-level wind shear.

The ATIS at VCV had winds at 150 degrees at 22kts gusting to 32kts and the density altitude was getting a little over 4,500 feet from the heat.

On departure from VCV we would be near maximum takeoff weight making the density altitude more important.

The 15,050 foot long runway 17/35 was closed but we still had 9,138 foot long 3/21.

The ATIS was 50 minutes old so I checked the ASOS at VCV and it didn’t answer.

Winds were light and variable on the El Mirage lake bed just 11 miles east of VCV and our takeoff was as nice as could be.

There were two lenticular clouds over VCV letting me know this was probably not a good idea.

My new friend did a great job managing altitude and airspeed

I called Victorville tower from 8 miles to the west at 3,900 feet inbound with Tango and she asked for my call sign twice. I was to make right traffic for runway two one and report mid field down wind.

I asked my new friend if he had the airport in sight and he responded in the affirmative. I suggested we aim for a forty five degree entry to the pattern. It turned out not to be the airport and I had some trouble picking VCV out in the blowing dust with about six miles visibility.

There is a rotor that comes off the lee side of the ridge that causes considerable sink, turbulence and a wind shear near the ground.

My friend was overcorrecting despite my consul so I took the controls and began a somewhat bumpy entrance to the pattern.

Before I could report I heard the tower say Gyroplane Two Mike Golf, runway 21 clear to land and you can use the ramp if you prefer. I took her up on her offer and she said; “I have worked you at San Luis Obispo and Whiteman, I know what you can do Vance.” 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.

We filled up and called ground with Uniform with a request to taxi to runway 21 and they suggested an intersection departure at Bravo. I asked for runway 21 full length and was to taxi to runway two one via Charli Alpha.

The wind and turbulence increased as we made the magneto check and prepared for takeoff.

The blades got up to speed quickly. I was showing 40kts indicated air speed at ten knots of ground speed waiting to see 300 rotor rpm before adding full power. A gust popped us ten feet into the air with less the 15kts of ground speed showing 45kts indicated airspeed.

The climb out was ugly feeling like we were being dribbled down the runway as we would hit the wind shear and descend. We used the entire 9,138 foot runway to achieve 3,400 feet msl (515 feet agl).

On our flight back we were at full power most of the way till we found an up draft and saw 1,500 feet per minute on the VSI.

On our return there was dust on the east end of El Mirage but at gyro cove it was about seven knots out of the west and landing was easy.

I checked the ATIS at VCV and it was 150 degrees at 23kts gusting to 37kts. This is over my gust limit and I would not have flown.

What did I learn again?

Don’t hesitate to cancel a flight for wind particularly with a passenger.

Don’t press your wind limits away from your home airport.

Gusts and turbulence are what cause the challenges.

Wind can be very local and be radically different just five miles away or a few minutes later.

Respect the warning sign of lenticular clouds.

The ATIS is only accurate at that place for that moment when it is recorded.

Even a wind check is subject to rapid change.

The tower is there to help.

The wind speed and direction can change rapidly in a very short distance.

Gyroplanes are affected by the winds.

Being near maximum takeoff weight combined with a density altitude or 4,500 feet reduces takeoff and climb performance.

Don’t imagine that because it worked out it was good aviation decision making.

As Frank Borman said;

“A superior pilot uses his superior judgement to avoid situations which require the use of his superior skill.”

 

[eddie]

At the end of 33 in Socorro NM we have unusual terrain that will cause a wind shear, even with very little wind reported.

And at the other end on15 we have a permanent down draft because of an arroyo.

I normally do midfield takeoffs and turn out before the runway ends to avoid the problems.

I have always assumed that if I were to have an aviation accident it would be weather related,

 

[HighAltitude]

I am not following how you guys can look at terrain and predict a potential wind shear condition. I have never really worried about wind shear in a FW aircraft. Can you go back to the basics and explain how we can predict it?

 

[Vance]

I am not following how you guys can look at terrain and predict a potential wind shear condition. I have never really worried about wind shear in a FW aircraft. Can you go back to the basics and explain how we can predict it?

I am not able to look at ground features and predict wind shear Tim.

As per your request here is a good FAA publication covering the basics of wind shear.

Wind Shear Defined: Wind shear is a change in wind speed and/or direction over a short distance. It can occur either horizontally or vertically and is most often associated with strong temperature inversions or density gradients. Wind shear can occur at high or low altitude.
A link to an FAA Safety Publication on low altitude wind shear.
https://www.faasafety.gov/files/gsl...7/FAA P-8740-40 WindShear[hi-res] branded.pdf

Going to this site may help you visualize the way wind flows around a particular place at a particular time.
https://www.windy.com/?36.204,-115.159,7

Shortly I will try to write something more specific about how wind shear affects gyroplanes differently than fixed wings and why.

 

[Vance]

Some more thoughts on wind and gyroplanes.

The approach to runway three zero at the Santa Maria public airport has the Radisson hotel off to the right. It the wind direction is near 030 degrees over around 20kts there is turbulence on the leeward side of the hotel and we often get wind shear near the numbers. I have seen a twenty knot change in indicated air speed over about 30 feet near the numbers.

Because I am approaching at only 50 knots this tends to increase the angle of descent until airspeed can be recovered. Gyroplanes have a very steep increase in power required as the airspeed decreases below about forty five knots.

This is a part of why I use the thousand foot markers for my aiming point rather than the end of the runway.

The low speed of rotorcraft can exacerbate problems with wind shear and rotors because it takes so long to fly through them.

On the way back to El Mirage Dry Lake from VCV I was almost parallel to the ridge line so I remained in the rotor for about five miles at full power where I should have been climbing at around five hundred feet per minute even at five thousand feet density altitude near maximum takeoff weight. When I found the lift the has to be near a down draft I saw over fifteen hundred feet per minute climb

In Santa Barbara there is a common AIRMET for winds shear when we have the Santa Ana Winds from rotors over the four thousand foot ridge just over five miles from the airport that is close to sea level. I have had to tell Santa Barbara Approach unable to maintain altitude several times because of the down drafts. Local knowledge helps. The down draft usually does not go all the way to the ground.

The leeward side of a ridge with a wind over thirty knots will often develop a rotor and sometimes mountain wave activity.

An interesting article from The Front, a National Weather Service publication about mountain wave activity and the significance of the lenticular clouds is found here:
https://www.weather.gov/media/publications/front/11nov-front.pdf

 

[HighAltitude]

No Title

Thank you. Great links and great information. As you know, I learned and have flown in the mountains for several years. I am always very careful in my area and deal with turbulence on every flight. It is very predictable but I never refer to it as wind shear. I will in the future. I am interested in this topic because I now live in a new area, below a flat mesa in a very windy and hot climate. I am anticipating that Mesquite NV is going to be more challenging than the Lake Tahoe area. The leeward side of the mesa has my attention. I have stuck up friendships with a couple of FW guys that live here. I am going up in a kitfox soon to explore the area and get some much needed pointers regarding the wind and the DA.

 

[Kolibri]

Having dinner last night with a pilot friend and his wife, he was scrolling through his phone to show me websites and photos of interest,
and mentioned Vance's Facebook page about this turbulent flight, while shaking his head at the folly of it. I had a look here at it, and was stunned.

Before the flight, Vance knew of:

AIRMET for high and increasing winds/wind shear
150 at 22G32, 60° x-wind at VCV Runway 21 due to closed Runway 17
DA of 4500+
passenger weight and full fuel for return takeoff and climb would be near MGTOW​

In taking off for VCV he later admittedly made "a poor aviation decision".
What stunned me is that he continued to make them after taking off.
He had plenty of warning during the trip that sustained winds and gusts were increasing.
Instead of turning back to El Mirage, he chose to fly into clearly worsening conditions:

VCV winds, old: 150 at 22G32, DA4500+
VCV winds, enroute: 150 at 26G36
VCV winds, landing: 150 at 28G38 (with two lenticular clouds above)
VCV winds, takeoff: more than 28G38 (i.e., 30G38+), 60° x-wind on Runway 21​

Not taking off would have been wise, and turning back would have been prudent.

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;

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.

The choice of vertical descent and 30kt AS seems to me an inappropriate one.
(What gusts giveth, gusts shall taketh away . . . )
During strong gusts, I prefer to come in at a flatter angle and with more airspeed.
This reduces the effect of gusts, and gives me more energy to deal with them.

If vertical descent at low AS is a better technique, I'm open to learning why.

Landing at Taxiway Bravo (presumably at 120°, reducing x-wind to 30°) was an unexpected gift, but how did he plan to get out of there on Runway 21?

The blades got up to speed quickly. I was showing 40kts indicated air speed at ten knots of ground speed waiting to see 300 rotor rpm before adding full power.
A gust popped us ten feet into the air with less the 15kts of ground speed showing 45kts indicated airspeed.

The takeoff was quite an experience with the gusts popping us up and dropping us down cocked about thirty degrees to the runway heading.
We were in the down side of a rotor from the ridge and each time we would get some altitude it would push us back down.
We used all 9,138 feet of runway two one to get 500 feet of altitude above the ground.
I was seven miles into the flight before I reached my cruising altitude of 3.900 feet (1,000 feet above the ground).

He and his passenger barely got out and away from VCV.
They were very lucky not to have been stuffed into the runway by wind shear.

What did I learn again?

With 2000+ hours and being a gyro CFI, why must Vance learn such basic safety precautions "again" at all?
And why he must do so with a passenger is, for me, the most baffling and alarming.

“A superior pilot uses his superior judgment to avoid situations which require the use of his superior skill.”

Why does he offer such a valuable nugget of Frank Borman wisdom if it's to be ignored?
If he insists on taking such huge chances with weather, I hope he will no longer do so with a passenger.
While I doubt that Vance will listen to me about this, perhaps his flying friends may intervene.

I post this without "bile" or a snide lecture, but I truly do not understand Vance's mental processes and decision making.
As did my pilot friend last night, I'm also shaking my head at this flight made by somebody of Vance's experience.

That aside, I appreciate the good info here about rotors and wind shear. They are not to be trifled with, even in more forgiving gyros.

Safe flying,
Kolibri

 

[eddie]

Vance probably has more hours flying in conditions like that than most of us have in total hours.

His decision to fly that day was based on current conditions that were within his parameters, and his experience to fly safely in high winds

which came up,and he handled the high winds very well.

I didn't read any where that he thought he was in danger,or he feared for his,or his passengers safety

What is bad decision making is criticizing someone for having a skill level that is way above yours,

and not being able to understand it.




Would I have flown in those conditions,absolutely not,no way,not now ,not ever,thats way above my skill and comfort level,

but do I criticize his decision to fly in those conditions,certainly not,would I have flown with Vance in that wind,yes, absolutely,

 

[GyrOZprey]

I saw Vance heading over to VCV as I was driving onto the lakebed. I was amazed that he of "the low fear threshold" mindset was going to refuel when the winds at Victorville were so crazy! ...I also could not believe how dramatically the winds changed during the 15 mile drive out to gyro cove! The winds were howling & blowing sand & dirt in Victorville where I was staying ... yet on the N W end of the lake bed ...a gentle breeze!

I really liked Vance's line by line presentation of the whole experience!

I applaud Vance for posting his good & not so good flight adventures & decision making ....that we might all learn from his experiences ... Vance with his many many hours in the fickle winds @SMX is the best qualified of all gyro pilots to make GO-NO-GO decisions facing windy challenges!

As the person in tower was familiar with Vance flight skill set & his gyro ... she offered/approved a non conventional landing! THAT SAYS A LOT!!! - right there!

Given the conditions at gyro cove ... it would be easy for a less meticulous weather info researcher to discount the accuracy of the info from VCV ... just 10Nmiles away!
When underway Vance got an ATIS update... and still felt it was within his personal wind range!

I would have returned & awaited better conditions ... because that wind range is out of my comfort zone! I totally agree with Eddie's assessment above!

 

[Kolibri]

I didn't read any where that he thought he was in danger,or he feared for his,or his passengers safety

No? I did, when he described being "dribbled" down the runway by the mountain rotor and needing all 9,138' of runway to reach a mere 515 AGL.
They were clearly in danger then; let's not sugarcoat things.

His decision to fly that day was based on current conditions that were within his parameters, and his experience to fly safely in high winds

eddie, he already correctly called it for what it was: "a poor aviation decision". That means, in retrospect, he shouldn't have flown to VCV.
I'm glad it worked out, but it's obvious that it barely did. Just a few minutes later conditions had worsened past even Vance's gust limits.

I'm not challenging Vance's skill, but his judgment that day. He cut things far too closely, and with a passenger.
With 2000+ hours of experience, shouldn't one become more conservative in such wind decisions?


______

When underway Vance got an ATIS update... and still felt it was within his personal wind range!

But, Chris, ATIS values are not carved in stone, as Vance himself wrote:

The ATIS is only accurate at that place for that moment when it is recorded.
Even a wind check is subject to rapid change.

I applaud Vance for posting his good & not so good flight adventures & decision making ....that we might all learn from his experiences

I somewhat agree, but I think it preferable and expected that pilots with that level of skill should concurrently show the wisdom of turning back.
When you have lenticular clouds over the airport and the tower offers a taxiway landing, how many more clues does one need?

I can perhaps see (although I wouldn't have done so) taking off and then reaching VCV to make a landing decision then.
But a decision to land means having to take off after refueling. (Had VCV been homebase, landing would have been more justifiable.)
Many times I've rejected a landing not because of the landing itself but because taking off later would have been too dicey.

With the trend of increasing wind, I cannot envision any rational confidence of departing VCV some 20+ minutes later.
(Not only that, reading another post of his, they seemed in no hurry to depart and spent some time in the FBO.)

My point was corollary: it was a series of poor decisions in not turning back midway, or after reaching VCV.
As I wrote, once in the pattern how did he imagine how he was going to get out of Runway 21?

30G38+ in a 60° x-wind? Near max gross weight with 5000' DA? Really?

It's an odd tale.
Only a skill level like Vance's managed (barely) the horrific departure conditions, but only his baffling nonchalance approved the flight at all.
As I wrote, I truly do not understand his mental processing that day.

Regards,
Kolibri

 

[Vance]

I have a primary student coming for his first lesson at noon and need to get ready for his lesson so I don't have time to edit this. I modify the syllabus based on what I learn from a telephone interview and it takes me time to get prepared so I can fit as much into two hours as they can absorb.

Some random thoughts on wind in no particular order:

The purpose of my wind limit is to more easily make the decision to fly or not to fly. My wind limit at Santa Maria (SMX) is thirty five knots with a ten knot gust spread. If I take off at my limit it would be reasonable to expect the winds may change and be higher in both speed and gust intensity upon my return. SMX has an eight thousand foot long by one hundred fifty foot wide runway so it is easy to land with zero roll into the wind at anything over twenty knots. I don’t usually fly passengers in those conditions because they often find it disquieting.

The primary reason for my personal gust limit is I find the rotor difficult to manage during spool up and spool down and securing the aircraft can be problematic in high winds because The Predator doesn't have a parking brake.

In my opinion the effect of airspeed on an aerodynamic surface goes up or down by the square of the change in the speed. In other words the air speed has four times the effect at thirty knots as it does at fifteen knots.

In my opinion all aircraft fly on indicated air speed and wind is a ground reference term.

In my opinion landing is a ground reference maneuver so the direction of the wind becomes more important.

Because of the proximity to the ground the gust intensity is also important.

The Predator will typically fly straight and level with full power down to about twenty two knots at maximum takeoff weight at sea level. Below that speed she will begin a casual descent. I don't have enough experience flying The Predator at higher density altitudes to be precise on the minimum straight and level flight. The last time I taught recognition and recovery from low air speed and high rate of decent at 4,500 feet density altitude we had to get down to seventeen knots indicated air speed to achieve a high rate of decent at full power. I doubt the accuracy of the airspeed indicator below twenty knots.

After experimenting I have determined that with the engine at idle; twenty knots indicated airspeed is plenty for the round out and flair in The Predator. The practical test standard for landing approach speed is plus or minus five knots so I picked 50 knots for an approach speed and that gives me plenty of leeway to save a client's untidy landing.

At San Luis Obispo where I fly often there is sometimes a horizontal wind shear right where I want to touch down and in high winds I typically just slow my ground speed to near zero and let her turn into the wind. It is not unusual for it to be a fifty degree turn.

It is my observation that unless it is from a collapsing thunderstorm or a microburst vertical wind shear doesn't typically go all the way to the ground.

Sothern California Logistics (VCV) has a 9,138 foot long by 200 foot wide runway plus lots of unobstructed concrete on the ramp.

I feel comfortable landing The Predator in twenty feet in a twenty knot wind so two hundred feet is kind of expansive.

Taking off in 200 feet in a twenty knot wind is pretty simple. I can let the rotor spool up in place to near flight rpm holding her in place with the throttle. When I am ready for takeoff a very short roll is possible.

At VCV we were off in about twenty feet of ground roll using this technique.

I don't know why landing a gyroplane with more ground speed in gusting conditions would be a preference of a gyroplane pilot. In my opinion a tip over is the greatest risk when landing in strong gusting conditions and in my opinion more ground speed at touch down exacerbates that risk.

My friend with 70 hours of flight experience in a 172 and I made the decision to fly to VCV together after discussing how winds affect gyroplanes and the developing weather at some length. We also discussed at length the decision to take off in those conditions from VCV. My primary concern was what conditions would be like back at El Mirage Dry Lake. Dust would make it difficult for me to identify the distance to the ground on landing. It turned out that conditions were benign.

In retrospect it was a poor aviation decision to take off because it was his second flight in a gyroplane and he admitted to being frightened by the violence of the winds as he tried to reconcile it with his 172 experience. In my opinion if I am trying to get someone to embrace gyroplanes scaring them on their first flight is not a good approach. He had a pretty big smile when were returned. I don't know if it was because it was fun or because he was glad to be back on the ground.

We were at greater risk because of the conditions and we both made the decision to fly and accepted that risk.

I learn every time I fly. Some of what I learned is a refinement of what I have learned before. I thought that was true of all pilots.

The Predator is particularly well suited to managing winds and gusts because she is near centerline thrust and has a generous vertical stabilizer and rudder. The Predator has generous horizontal stabilizer volume. She has a wide track and a long wheel base with a free castering nose wheel.

I hope people will not imagine they should try my wind limits with less experience or with a less suitable aircraft. I raised them incrementally over ten years.

In the Cavalons I have flown at SMX my solo wind limit is thirty knots with a ten knot gust spread and when training with an experienced student twenty knots with a five knot gust spread and a five knot crosswind component.

I have not found my wind limits in an American Ranger because of lack of opportunity. I suspect they would eventual be higher than The Predator.

My personal wind limit for training a particular primary student in his high thrust line RAF with a Boyer horizontal stabilizer at SMX is ten knots with a five knot gust spread and a three knot cross wind component. I will progressive raise the wind limits as we both gain experience with the aircraft. I suspect the eventual limit to be around 20kts with a five knot gust spread. That will keep us on the ground often at SMX.

If anything here seems puzzling or requires clarification please be clear in your question and I will try to share my opinion based on my experience.

 

[Vance]

No Title

Thank you for the kind words Chris and for verifying just how extreme the conditions were.

I am glad you read it as it was intended.

It seemed to me a good opportunity to describe preflight weather research and flight planning as well as the effect of various winds and turbulence.

I was hoping someone ask some good questions so I could expand some of the salient points.

I found the conditions remarkable and a good reminder of how different wind can be just a few miles away.

It reads to me like you very much understand aviation decision making.

In retrospect I should have offered you a ride in The Predator and I apologize for that omission.

In my opinion you are a great ambassador for gyroplanes Chris and I am proud to know you.

 

[Kolibri]

I don't know why landing a gyroplane with more ground speed in gusting conditions would be a preference of a gyroplane pilot.
In my opinion a tip over is the greatest risk when landing in strong gusting conditions and in my opinion more ground speed at touch down exacerbates that risk.

It is my observation that unless it is from a collapsing thunderstorm or a microburst vertical wind shear doesn't typically go all the way to the ground.

You described vertical wind shear at VCV's taxiway, not horizontal. The bottom did drop out on you there.
Thus I questioned your low AS vertical descent technique to land during a mountain rotor.
I was taught to penetrate that block of air with good AS, low to the deck, and then bleed off the energy for the landing.

My wind limit at Santa Maria (SMX) is thirty five knots with a ten knot gust spread.

I checked the ATIS at VCV and it was 150 degrees at 23kts gusting to 37kts. This is over my gust limit and I would not have flown.

Definable limits are valuable, I agree.
Do you mean limits of >35kts sustained and concurrently a >10kt gust spread, or either one occurring independently?

With your wind/gust limits do you not factor in excessive x-wind components?

In retrospect it was a poor aviation decision to take off because it was his second flight in a gyroplane and he admitted to being frightened by the violence of the winds as he tried to reconcile it with his 172 experience.

That's why it was a poor aviation decision? Because the passenger was frightened?
Thus, had you flown alone it would not have been a poor aviation decision?

He had a pretty big smile when were returned. I don't know if it was because it was fun or because he was glad to be back on the ground.

Since you didn't ask him, I suspect that you didn't have to ask him for an obvious answer.
Also, a 70 hour C172 pilot's opinion about gyros in wind would be nearly worthless.
He trusted and concurred with your judgment. You might consider that he did not understand what he was signing up for.

Perhaps with newbie passengers you may consider reducing your wind/gust limits? Just a thought.

To reiterate what I hope was clearly my point: while the winds may have been within your limits even at time of landing, they weren't forecasted to remain so.
And they did not. You'd have been stuck at VCV just a half hour later with winds from 150 at 23G37.

I do applaud your candor, and I try not to use such against people here because I don't want to discourage frank discussions.

For me, as I read your account, when I got to the part where Runway 17 was closed during strong winds/gust out of 150, I thought to myself, "Uh, oh! "
That would have triggered a very strong caution to me. The AIRMET for 30+kts sustained plus low level wind shear would have cinched the matter.

However, in my opinion, you cut it far too closely, but are reluctant to admit it.
Hence, you're likely to do it again. As you've often quipped, "Overconfidence is my nemesis."
At this rate, you're headed for a very big scare, or worse. I would not prefer that for you, despite our differences.

Regards,
Kolibri

 

[WaspAir]

But a decision to land means having to take off after refueling. (Had VCV been homebase, landing would have been more justifiable.)
Many times I've rejected a landing not because of the landing itself but because taking off later would have been too dicey.

We certainly part company on this one. We're talking about two different legs/flights; one inbound, one outbound. Landing at the end of one leg never imposes an obligation to depart in the same (or worse) conditions for the second. I strongly suggest that there is little danger in sitting on the ground after a safe landing, and no requirement to depart again promptly. Linking the landing and later departure decisions smells of get-home-itis to me and can itself contribute to an accident chain. I think it's a thought mode driven by destination desire, not safety.

I make decisions as you propose (linking landing with an obligation to depart) only in the very rare event when I am considering a truly marginal landing spot, marginal because of size and surrounding obstacles, not merely current wind conditions. It is possible to get an A&S 18A into tight spots from which it cannot be flown out at all, regardless of transitory conditions, because it won't jump high enough to clear everything. Landing at a big airport, with temporary weather conditions that might make immediate departure unwise, is not comparable; instead, it is a situation that will certainly be cured by passage of time.

My point was corollary: it was a series of poor decisions in not turning back midway, or after reaching VCV.
As I wrote, once in the pattern how did he imagine how he was going to get out of Runway 21?

30G38+ in a 60° x-wind? Near max gross weight with 5000' DA? Really?

With winds like that, who needs a runway?

Some years back I flew a McCulloch J-2 into NutTree/Vacaville when there was a 40knot direct 90 degree crosswind at the single runway. I landed into the wind and across the runway, touching down on the centerline, with no ground speed. When I chose to depart, I pointed into the wind and essentially levitated, with 40knots of airspeed on the ASI already before obtaining any groundspeed at all. I didn't have to worry about confusing any fixed wing traffic because there were no fixed wing aircraft that could handle that situation and I was the only one flying at the time.


On a separate note, I wonder if Vance's "dribbling" by the mountain wave rotor might have been reduced by not holding to the runway centerline. Normal, good conditions operations usually involve tracking the centerline, but in abnormal conditions, ATC can allow penetration upwind or drifting downwind as traffic may permit, perhaps enough to evade the condition.

 

[Kolibri]

Landing at the end of one leg never imposes an obligation to depart in the same (or worse) conditions for the second.

Of course it wouldn't, I agree.
By my "But a decision to land means having to take off after refueling" I only meant that if he wanted to return to El Mirage on Saturday after refueling.
I wasn't enunciating any kind of policy.

I strongly suggest that there is little danger in sitting on the ground after a safe landing, and no requirement to depart again promptly.

I certainly agree.
However, since the forecasted winds for later in the day were even worse, there was apparently no option of waiting on the ramp after refueling.
Having the gyro stranded there overnight would have been a hassle, and he narrowly avoided that.
Hence, pressure to make the round trip quickly.

I am conservative about making trips, and am wary of external pressures to do so.
In fact, I just rescheduled a commercial flight to pick up my airplane, because my return flying would have been in souring weather.

I'd have not made the VCV flight, but gotten a ride into town for the fuel. Somebody at the fly-in would have had a few gas cans.

With winds like that, who needs a runway?

Sure, I've also pointed into what would otherwise be a strong crosswind and basically levitated after spool up.

However, what made VCV different that day was the strong mountain wave rotor, and wind shear was specifically mentioned in the AIRMET.

Regards,
Kolibri

 

[Vance]

You described vertical wind shear at VCV's taxiway, not horizontal. The bottom did drop out on you there.
Thus I questioned your low AS vertical descent technique to land during a mountain rotor.
I was taught to penetrate that block of air with good AS, low to the deck, and then bleed off the energy for the landing.

Regards,
Kolibri[/COLOR]

I don't see a question mark; I will try to answer what might be the question with a quote from post one.

"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."

I don't see anything about a vertical wind shear in what I wrote.

I wanted to land with power for increased rudder authority and in The Predator I either need to reduce power or slow my indicated air speed to descend.

In The Predator I begin my round out at 20 feet.

I was not in a mountain rotor because I was very near the ground and a vertical shear usually doesn’t go all the way to the ground. The wind speed simply diminished increasing my rate of descent and requiring a burst of power to arrest the descent.

From post eight by Kolibri: "During strong gusts, I prefer to come in at a flatter angle and with more airspeed.
This reduces the effect of gusts, and gives me more energy to deal with them."

Would you please explain how that landing technique works for you in turbulent conditions?

 

[Vance]

Definable limits are valuable, I agree.
Do you mean limits of >35kts sustained and concurrently a >10kt gust spread, or either one occurring independently?

With your wind/gust limits do you not factor in excessive x-wind components?



That's why it was a poor aviation decision? Because the passenger was frightened?
Thus, had you flown alone it would not have been a poor aviation decision?



Since you didn't ask him, I suspect that you didn't have to ask him for an obvious answer.
Also, a 70 hour C172 pilot's opinion about gyros in wind would be nearly worthless.
He trusted and concurred with your judgment. You might consider that he did not understand what he was signing up for.

Perhaps with newbie passengers you may consider reducing your wind/gust limits? Just a thought.


Regards,
Kolibri

My wind speed limit is thirty five knots.

My gust spread limit is is ten knots.

No; I don't factor in cross wind component because in a gyroplane there is no reason to land with a cross wind.

Yes it was poor aviation decision making because my friend was frightened.

It would have been fine if I had been flying with many of my other friends.

I did ask him what he thought of our adventure and he felt it was great fun.

He only admitted to being frightened on direct questioning about his emotions. I suspect it was fun in a good way, sort of like a roller coaster ride.

I have a distaste for fear so in my opinion it was a poor aviation decision.

It appears to me I did not read him well on our pre-flight briefing.

 

[Vance]

On a separate note, I wonder if Vance's "dribbling" by the mountain wave rotor might have been reduced by not holding to the runway centerline. Normal, good conditions operations usually involve tracking the centerline, but in abnormal conditions, ATC can allow penetration upwind or drifting downwind as traffic may permit, perhaps enough to evade the condition.

Victorville tower offered both an intersection departure and proceed on course at pilot’s discretion.

I preferred to be over the runway for its entire length.

The down draft continued most of the way to El Mirage Dry Lake ending with a very strong updraft.

I was wide open most of the way to El Mirage.

The dribbling was not all the way to the ground. Each time we would climb above 550 feet the rotor would push us back down with authority.

 

[HighAltitude]

I have taken from this thread that my mind is in the right place as I wade into a new aircraft class in a new environment. I am slightly obsessing over it. I am not in the optimum situation of moving to a gyrocopter from a FW in my familiar previous "home" location where I knew every spot within 50 miles that caused wind shear and turbulence. I find myself staring at a new area and a new aircraft. My goal is to be much better at reading the conditions of ANY area I venture into. I plan to travel with my gyro. My weather skills are novice at best even though I was trained by Paul Hamilton who authored the video "Weather to Fly". I have so much more to learn.

I appreciate the insights here.

 

[Kolibri]

From post eight by Kolibri: "During strong gusts, I prefer to come in at a flatter angle and with more airspeed.
This reduces the effect of gusts, and gives me more energy to deal with them."

Would you please explain how that landing technique works for you in turbulent conditions?

Ever heard of adding half the gust factor to one's normal airspeed on final?

Yes it was poor aviation decision making because my friend was frightened.

It would have been fine if I had been flying with many of my other friends.

Even though you'd have been stuck at VCV just a half hour later?
You barely got out of there, and that's not cutting it too closely?

OK, I've expressed my opinion and made my point. You disagree with it.
Thanks for the polite exchange. Good day.