Demonstrated Crosswind Component

[Tristar]

As a private student, I was taught that it wasn't smart to exceed the demonstrated crosswind component in the airplane I was flying. Now considering I was taught private in Florida, winds rarely exceeded that except during hurricanes. Thus the thought was never there. I moved to Oklahoma where my skills increased and I'm able to fly in winds that weren't available previously. I'm working on CFI and now run across the question of Demonstrated Crosswind components. So to those of you that are CFIs especially, is it better to teach a private student what they and the aircraft can handle which may be past DCC, wait until they are in upper stages of training, or to teach them not to exceed the DCC even though its only demonstrated and they'll probably exceed it later anyways?

 

[KennyFlys]

I won't normally make flights with such strong crosswinds (usually less than 10XW) but I will take an opportunity out there to make it part of practice. Though rare, there may be a time when they will need that ability. It's better they know the potential issues and learn now rather than face it alone the first time encountered.

 

[flhrci]

As a private student, I was taught that it wasn't smart to exceed the demonstrated crosswind component in the airplane I was flying. Now considering I was taught private in Florida, winds rarely exceeded that except during hurricanes. Thus the thought was never there. I moved to Oklahoma where my skills increased and I'm able to fly in winds that weren't available previously. I'm working on CFI and now run across the question of Demonstrated Crosswind components. So to those of you that are CFIs especially, is it better to teach a private student what they and the aircraft can handle which may be past DCC, wait until they are in upper stages of training, or to teach them not to exceed the DCC even though its only demonstrated and they'll probably exceed it later anyways?

I have adopted a policy of not exceeding the DCC. You have to decide what benefit the student will receive from doing this. I look at going beyond the DCC as an unknown performance area. You might be fine, but then you might not. The 172R has a DCC of 15 knots. If the wind is that high, find a crossing runway.

Today the winds were gusting as such and a big enough angle from our runways that the crosswind component as calculated was going to be 17 or higher. None of us CFI's were flying. The gusts were upwards up 32 knots at one point, and msot of us were cancelling with 35 knot gusts. I do not really want to voluntarily deal with a DCC of more than 12 really.

If there was absolutely no risk of losing my job or being sued or getting hurt, I might have tried it. I have decided to managa the risk level by not going.

It is up to each CFI and any established operating limits by your particular school. I choose not to take certain risks.

Hope this helps.

David

 

[poadeleted20]

In my instructorial experience, it's best to teach the trainee how to tell when his/her own limit is being reached rather than to couch it in terms of the airplane's limit. In most every case, the airplane can handle more than the pilot flying it, so the key is knowing when to say when and then go find another runway better aligned with the wind (at that airport or an other). For Student Pilots, the CFI will have to assist in this process, and establish appropriate crosswind limits to put in the student's solo endorsements. After that, it's up to the individual pilot to work out a process for making this determination, and I don't think the aircraft's MDCC is nearly as important as the pilot's own skill and proficiency level in that process.

 

[jesse]

I think the demonstrated crosswind component is crap (it is just something for you to know) and behind afraid of it is a poor thing to teach a student. How exactly do you know what the real cross-wind component is? Are you going to run the math in the air? Conditions change *every second*.

One minute the component might be way below the demonstrated component and the next it might be above. The trick is to learn how to fly the airplane and learn how to judge the landing in high winds. If you can't get aligned with no drift you don't touch down, no harm. If you do--you land. Deciding if you can handle the wind isn't rocket science just takes a little skill and judgment.

Basically--I'm saying the demonstrated crosswind component is one small part of figuring out if you can land the airplane safely. Focus too much on it and you end up with crappy pilots.

 

[Matthew]

I trained in a Warrior - I'm trying to remember, but I think the Demonstrated XW is 17kts?

That's a heckuva lot for me - the most I flew in (with my CFI) was 15kts direct. We had to go to another airport to do it, but after about 10 t&gs I got signed off in my logbook at 13kts xwind.

I'm not sure what my CFI would have done if we would have ever had a direct xw greater than 17kts. I doubt we would have flown in it.

I was told during training - exceed at your own risk.

My current renter's agreement prohibits operation in winds exceeding the demonstrated xw.

 

[sba55]

From what I understand, the demonstrated XWC means just that - it's the maximum XC landing demonstrated during certification. I don't think it means that it's the best the airplane can do, or anything like that. Depending on the winds on the days when the certification happened, it might be quite high in some airplanes, but low in others.

I think it's a fairly useless number. If it's 20 knots, maybe that means that 40 knots are too much, but maybe it doesn't. If I were teaching student pilots, I'd see what they are comfortable with, and I suspect that it's probably going to be less than the
XWC.

-Felix

 

[Tristar]

I definitely agree with you guys. I believe respect should be taught to the student and a private candidate will need assistance with this but when it comes down to it, it is really what you, as a pilot, are comfortable with. Like many schools such as mine, I also have to comply and teach students to comply with their standards. Thankfully, they're pretty easy going and understand we live in Oklahoma. Anyone who starts their training in a windy state is ahead of the game.

 

[midlifeflyer]

In my instructorial experience, it's best to teach the trainee how to tell when his/her own limit is being reached rather than to couch it in terms of the airplane's limit. In most every case, the airplane can handle more than the pilot flying it,

I disagree a bit with the second half - there are parts of the country where the winds tend to blow a bit stronger on a regular basis - but that first part is absolutely on the button.


To go back to Tristar's question, I teach in an area where the winds are relatively light and down the runway in the mornings, and increase in both strength and location to produce significant gusty crosswinds in the afternoon. I try to keep most of my stuident's lesson in the morning at the beginning and start moving into the windy periods as the pilot's skill level increases to meet the challenge.

In terms of exceeding the "demonstrated" component, while I don't buy into the "you're a test pilot if you exceed it" mentality, if that wind exceeds your capability and you ball up the airplane, be prepared to answer some questions about both your skill and your judgment.

 

[Tristar]

Liability vs. teaching safe/smart pilots will forever be a question.

 

[Anthony]

I disagree a bit with the second half - there are parts of the country where the winds tend to blow a bit stronger on a regular basis - but that first part is absolutely on the button.

Yeah at my former home base at KFTG I had a direct, 90 degree crosswind at about 30 knots, maybe a bit more, but it was steady and I used all the rudder on the Tiger on that one. Not a big deal. When they were gusty and shifting which was often it was a little different and interesting, but fun!

 

[markb5900]

Not a CFI, but I tend to believe the DCC as stated earlier is just that, the number it did on the day they were certifying it. I know it must be able to do xx amount to get certified and above that is just "gravy" so to speak.
Now as in Dave's case and others if your school or FBO has rules about it. Then so be it, it is their plane and their rules so you have to go by them.
As Mark stated, in some parts of the country (out west in the desert for instance) almost every day you are flying above the DCC, so you have to learn to do it or you don't fly at all.
I really don't care what the DCC is personally, I pretty much know my limits and if it is above them or I run out of rudder before I can get it straight, then I go to a different airport. I believe students SHOULD be exposed to pretty hefty x winds, you never know when they might HAVE to land in them due to fuel, sick passenger or some other reason.

Mark B

 

[Don Jones]

In my instructorial experience, it's best to teach the trainee how to tell when his/her own limit is being reached rather than to couch it in terms of the airplane's limit. In most every case, the airplane can handle more than the pilot flying it, so the key is knowing when to say when and then go find another runway better aligned with the wind (at that airport or an other). For Student Pilots, the CFI will have to assist in this process, and establish appropriate crosswind limits to put in the student's solo endorsements. After that, it's up to the individual pilot to work out a process for making this determination, and I don't think the aircraft's MDCC is nearly as important as the pilot's own skill and proficiency level in that process.

Exactly, I had one out this moring with 18kts x-wind component. He was working his butt off and decided that was more than he wanted to fly in. So we called it quits.

 

[TMetzinger]

I forget which airplane it is, but one of the airplanes I rent has an MDCC of something under 10 knots, though it's quite capable of handling much more. Guess they didn't have the ability to test it in good windy conditions.

As Ron and others have said, the limit/judgment of the pilot is more important

 

[jmaynard]

The Zodiac's MDCC is 20 knots. I've landed twice in bigger crosswinds than that (the alternatives were worse), and had no problems. (At least, not in landing.) The factory test pilot tells me he's landed a Zodiac in a 38-knot direct crosswind; I'm not about to try that.

I agree with Jesse: try it, but be ready to take it around, or elsewhere, if it doesn't work - and know when it's not working.

 

[Cap'n Jack]

During my PPL I was tought Xwind landings in a developing nor'easter- I was signed off for the max demonstrated. Once out here I landed in a stronger crosswind but was prepared to go elsewhere. I was taught to respect but not fear crosswinds.

If I demonstrate a stronger wind, can I "correct the POH?:smile:

 

[SkyHog]

Tristan - the DCC is useless, and doesn't tell you anything. Its not a redline, or Vne or something, its an arbitrary number that shows what condition the plane was flown in once.

I think a better way to teach would be to find a way to show what running out of rudder feels like. Its an interesting sensation, and could be mistaken for other feelings, so...

It'd be better than "xx" wind is too strong, why? No reason, just because this book says so.

 

[tonycondon]

ive found that about 15 knots direct crosswind requires full rudder travel on a 172 to do a perfect crosswind landing with no drift and be totally aligned with the runway. im sure it would possible to land with stronger wind. i can also certify that the 15 knot xwind gets pretty interesting on roll out when you hit that icy patch on the runway...

and its also a very good lesson for students to go out for just a few landings in those conditions. first should be demonstrated, and once they see what it takes in terms of constantly changing input to continually have the correct correction applied their crosswind landings will improve

 

[bbchien]

Tristar, stop an think for a moment about rudder effectiveness and landing speed, and it's effect on AOA.

If you have a taildragger, what do you think the upper limits of demonstrated crosswind are?

How about a tricycle gear like a Cessna 172, which are amazingly tolerant to landing at speeds well beyond 1.3 VSO.?

Lastly, think about ME aircraft that have the advantage of differential power.

 

[wabower]

By coincidence, I was learning to fly at your airport a few years back. Check your your Cowboy history to see when A&M became OSU and you'll know exactly when; or stated differently, those old guys they introduced at halftime two weeks ago were team-mates. :wink2: Unlike you, however, I can remember being relieved that the winds were consistently less than in western OK where I had been training before. OSU airport used a windsock, KELK used a chain. ba-boom.

Anyway, my goal has always been to be sure the student understands the entire concept, especially the component table. To this day, I have the concentric quarter-circle copied on the back of my checklist. The reasons now are different from the reasons then (now fly a taildragger and am more keenly interested in having it graphically displayed) but I think it's important that the student learn the importance of both the direction and the velocity, and have a firm understanding of the resulting component as they work their way up the XW skill ladder. Too many times I observe pilots listen to the ATIS and talk about velocity as though it's a deal breaker, without considering the component piece.

I also advocate taking a student who has mastered manageable crosswinds out for repeated approach and runway tracking practice on a day when the winds are much too strong to land (assuming there's another RW that will work). They won't ever land or risk the airframe, but they will learn a lot about cross-control inputs, and it is important that they see for themselves that it ain't gonna work, and also see if some of the other techiniques (aim at the downwind corner and angle slightly across, or reducing flaps and flying faster) will take out enough of the component that it might be possible to get it on the ground. I've seen pilots come dangerously close to exhausting fuel by trying over and over to land in a direct crosswind, when a perfectly aligned runway, fuel and restaurant were less than 50 miles away.

Anybody who has flown much, especially in the plains states, knows the airplanes will outperform the book in this regard, and must determine their own limits. Even so, I still say 15 when asked, just because it's a number I can remember and I know it's doable in most all conditions.

Yesterday a guy asked me to pick him up after he delivered an airplane to a radio shop. We checked the ATIS, found the wind was 50 degrees off the nose, 19G27. I passed on the trip, but told him that if it was really important we could have done it, but at this point I'm doing it for fun and those winds just make it too much like work.

I definitely agree with you guys. I believe respect should be taught to the student and a private candidate will need assistance with this but when it comes down to it, it is really what you, as a pilot, are comfortable with. Like many schools such as mine, I also have to comply and teach students to comply with their standards. Thankfully, they're pretty easy going and understand we live in Oklahoma. Anyone who starts their training in a windy state is ahead of the game.

 

[sba55]

Another thing I noticed is that 20G30 != 20G30.

For example, that wind speed at a 30 percent angle would be hardly noticeable around here in my Bonanza. However, when landing at Mountain Home before Gaston's this year, the winds were something similar to that, so I figured it'd be an easy landing.

Big mistake. The wind was in no way somewhat steady; instead, it was changing magnitude and direction all the time. I had to go around once. So, it really depends on the area and type of wind, too.

 

[MauleSkinner]

I feel strongly both ways...

If your flight school has rules regarding DCC, obviously you should abide by them...I know of one FlightSafety program manager who, in a previous life, balled up a Seminole while demonstrating his crosswind skills while working for a flight school that prohibited operations in excess of DCC.

On the other hand, I agree that a large percentage of pilots have terrible crosswind skills, particularly those who learn to fly at airports with multiple runways.

Personally, I've got no problem exceeding DCC in a training environment, provided it's well within what I'm comfortable with in the particular airplane. Most airplanes are capable of crosswinds well in excess of the DCC using normal speeds and techniques...there are a few, though, that have a DCC that is right at the limit of control authority using normal techniques. The Hawker 800 has a DCC of 30 knots. On takeoff, full rudder and full aileron will allow you to take your hand off the tiller at the normal 80 knots. Relax on either one, and you'll need nosewheel steering until well over 100 knots. As Bruce said, extra speed and differential thrust will increase controllability, but at the expense of runway required. LOTS of extra runway required. And only on clean, dry runways. I got the pictures from the investigating inspector a few years ago from when I showed how a little contamination decreases the crosswind capability substantially.

I really don't think it's necessary, though...I think that if you emphasize proper crosswind technique on EVERY takeoff and landing, rather than just the stronger crosswinds, you'll train a pilot who can better see and judge the corrections necessary. At least that's been my experience with guys I've brought into the Hawker...I harp on 'em about touching down straight, and before long crosswinds are a very natural operation.

In fact, the guy I flew with today requested 35 out of SWO, with the direct crosswind, rather than 22. Mostly because we had no clue how to get to 22, but still...

Fly safe!

David

 

[midlifeflyer]

Yeah at my former home base at KFTG I had a direct, 90 degree crosswind at about 30 knots,

Of course, before KFTG grew a tower, even with a runway 17/35, the locals would need a 30 kt direct crosswind before leaving the beloved 8/26

 

[tonycondon]

Another thing I noticed is that 20G30 != 20G30.

For example, that wind speed at a 30 percent angle would be hardly noticeable around here in my Bonanza. However, when landing at Mountain Home before Gaston's this year, the winds were something similar to that, so I figured it'd be an easy landing.

Big mistake. The wind was in no way somewhat steady; instead, it was changing magnitude and direction all the time. I had to go around once. So, it really depends on the area and type of wind, too.

yea thats an important point. im not sure what the algorithm is that determines when the AWOS/ASOS reports gusts. its too bad it cant somehow report the wavelength of the gusts. ive been out on days when it was 10G15 and i was getting completely rocked and rolled and other days with 20G30 that were pretty easily managed

 

[wby0nder]

Yea, this wavelength issue is something Tony and I have been discussing. It can make a huge difference and I think it would be good to have some kind of number to associate with it. With small slow airplanes it's almost equivalent to down burst wind shear on big airplanes. I think the lack of data on this is one reason there is so much variability in stories, lore, and personal limits.

 

[Anthony]

Of course, before KFTG grew a tower, even with a runway 17/35, the locals would need a 30 kt direct crosswind before leaving the beloved 8/26

Yeah I know. I remember on several occassions the wind shifting 180 degrees ever time I switched runways to be exactly the opposite of what I wanted. In the end I just sucked it up and used the big rudder to the stop routine. Besides it takes to long to taxi to your hangar from 17/35.

:smile:

 

[sdflyer]

So to those of you that are CFIs especially, is it better to teach a private student what they and the aircraft can handle which may be past DCC, wait until they are in upper stages of training, or to teach them not to exceed the DCC even though its only demonstrated and they'll probably exceed it later anyways?

I'm not CFI yet, but if I was I would teach my student to recognize personal limit crosswind

 

[gismo]

I'm not CFI yet, but if I was I would teach my student to recognize personal limit crosswind

Like I think Ron, David, and others said what needs to be learned by the student (and private) pilot is how to recognize their own limits. Personally I think this has almost nothing to do with the airplane's DCC nor with the reported conditions. The DCC could require skills way beyond the pilot's or the DCC might be so low that most students barely beyond solo could cope without raising a sweat. The actual wind will almost undoubtedly be different that what's reported so why use the report for anything more than an estimate of what might confront the pilot during landing. Could be better, could be worse.

FWIW, baring local influences like buildings and trees, in the northern hemisphere the wind will usually veer (come from a direction clockwise from the steady wind) when it gusts. That means that a gusty crosswind from the left is likely to be more difficult to handle than one from the right because when a gust occurs it will be more of a crosswind. This only applies when the steady wind is less than about 45 degrees off the runway heading, beyond that the angle of the wind has little impact on it's effect on the airplane.

 

[tonycondon]

Like I think Ron, David, and others said what needs to be learned by the student (and private) pilot is how to recognize their own limits. Personally I think this has almost nothing to do with the airplane's DCC nor with the reported conditions. The DCC could require skills way beyond the pilot's or the DCC might be so low that most students barely beyond solo could cope without raising a sweat. The actual wind will almost undoubtedly be different that what's reported so why use the report for anything more than an estimate of what might confront the pilot during landing. Could be better, could be worse.

FWIW, baring local influences like buildings and trees, in the northern hemisphere the wind will usually veer (come from a direction clockwise from the steady wind) when it gusts. That means that a gusty crosswind from the left is likely to be more difficult to handle than one from the right because when a gust occurs it will be more of a crosswind. This only applies when the steady wind is less than about 45 degrees off the runway heading, beyond that the angle of the wind has little impact on it's effect on the airplane.

interesting observation Lance, i had never thought of that. Why aren't you a CFI again??

although i would think that with gusts cause by thermal inflow/outflow during the summer, all bets are off.

 

[sdflyer]

FWIW, baring local influences like buildings and trees, in the northern hemisphere the wind will usually veer (come from a direction clockwise from the steady wind) when it gusts. That means that a gusty crosswind from the left is likely to be more difficult to handle than one from the right because when a gust occurs it will be more of a crosswind. This only applies when the steady wind is less than about 45 degrees off the runway heading, beyond that the angle of the wind has little impact on it's effect on the airplane.

I remember few years ago during Santa Ana gusty wings condition I was coming for landing the wind was changing 180 degrees so was my landing instruction from ATC

 

[Everskyward]

yea thats an important point. im not sure what the algorithm is that determines when the AWOS/ASOS reports gusts. its too bad it cant somehow report the wavelength of the gusts. ive been out on days when it was 10G15 and i was getting completely rocked and rolled and other days with 20G30 that were pretty easily managed

I wonder if this could also be due to gusts combined with up and downdrafts.

 

[tonycondon]

I wonder if this could also be due to gusts combined with up and downdrafts.

yea i think the days where ive experienced what i would call 'short wavelength' gusts were days where the gusts were due to thermal inflow/outflow. i just remember turning final in the supercub at about 200' and a 1/4 mile and all the sudden it felt like i was standing still and the world was coming up to greet me. quite challenging conditions

 

[timwinters]

I might get blasted for suggesting this but...

I was taught to fly by a retired army aviator and he taught me to use all the runway when needed. I.E. you don't HAVE to land on the centerline. You CAN land diagonally across a wide runway (turning slightly into the wind) to take some of the crosswind component out of the landing.

It can make a significant difference on a 150' wide runway!

 

[Cap'n Jack]

I might get blasted for suggesting this but...

I was taught to fly by a retired army aviator and he taught me to use all the runway when needed. I.E. you don't HAVE to land on the centerline. You CAN land diagonally across a wide runway (turning slightly into the wind) to take some of the crosswind component out of the landing.

It can make a significant difference on a 150' wide runway!

Blasted? Why? In Nebraska, I think you could land a C150 directly across the 150' runway in a crosswind

 

[timwinters]

Blasted? Why? In Nebraska, I think you could land a C150 directly across the 150' runway in a crosswind

I would never publicly admit to doing that in the '57 172 I formerly owned. But, had I done it, I would have had over 600' to work with counting the taxiway and empty ramp.

Heck, with winds like you're depicting I think you could land a 150 on a helipad!

 

[RotorAndWing]

I might get blasted for suggesting this but...

I was taught to fly by a retired army aviator and he taught me to use all the runway when needed. I.E. you don't HAVE to land on the centerline. You CAN land diagonally across a wide runway (turning slightly into the wind) to take some of the crosswind component out of the landing.

It can make a significant difference on a 150' wide runway!

Not at all, that's what the runway is for. Use it to your advantage.

 

[poadeleted20]

I don't agree with your Army aviator's idea. Using the whole width gives you zero margin for error on one side, and since winds often gust (which means they often drop velocity sharply, too), you can be off the runway before you know what happened. To my thinking, if you need that angle to be able to handle the crosswind, you should be using a runway more aligned with the wind, even if that means going to another airport.

 

[colomtnflyer]

In KDTA (Delta, Utah), it is not uncommon for the locals to use the taxiways rather than the runways on really windy days... (Not that I would ever do such a thing...)

While learning to fly and teaching at KCOS (3rd ranked worst x-wind airport in the US), you developed x-w skills very quickly on Rwy 17/35. But at least with Rwy 12/30 also available, it gives an out for those who would like it.

Much has been written about whether it is advisable to teach students while exceeding the MDCC. I think that becomes a case by case scenario- is the student capable of benefitting from the experience? The CFI must make that decision on behalf of the student.

But as liability has been mentioned- should the aircraft get pranged while landing when the MDCC is exceeded, don't expect the insurance companies to pay up, and if someone were to be injured or worse, it would be likely the FAA/ NTSB would have a finding of pilot error. No claim could be made against the manufacturer with that finding.

But I would fully expect the CFI who trained that pilot to be put on the carpet by the FAA/NTSB, about whether exceeding MDCC was included in the course of training.

Just because I bring up these points doesn't imply that I cower from doing what I believe is to the best for a student. No doubt I have personally landed in conditions exceeding MDCC. How or when I chose to do so was based soley on the circumstances prevailing at that moment. But the inherent skills necessary to do so were developed long before the need to perform at that moment.

 

[flyingcheesehead]

Of course, before KFTG grew a tower, even with a runway 17/35, the locals would need a 30 kt direct crosswind before leaving the beloved 8/26

Maybe because you have to taxi about 18 miles to get to 17/35?

I'm pretty sure that was the longest taxi EVER for me. Very nice airport, though.

 

[RotorAndWing]

But I would fully expect the CFI who trained that pilot to be put on the carpet by the FAA/NTSB, about whether exceeding MDCC was included in the course of training.

In the airline side of things, the FAA mandated in our training program X-wind training in excess of the Demonstrated Cross Wind Component.

Back when I was doing airplane training I would always take a student out on a blustery day and put them into a direct crosswind for take off and landing practice.

When I taught helicopters I would take my students out when it was blustery and have them put the tail into the wind and keep it there, then do 90 degree turns left and right while maintaining a hover over the same spot.