I don't like pushing the limit too far either, but when you're time building in bad weather and all you can do is do circuits for 5 hours straight, you get bored and want to try something different.

FullyFlapped,

It might have been quicker if you had sent it to the flight test department but it will probably get there after much of the "hey did you see what this idiot has done" internal emails.

So what test pilot training scheme have you graduated from?

Your test cards must make up an impressive attachment to the email you sent.

Your analysis of the results and the in depth report recomending the increase in maximum demonstrated crosswind component will no doubt make waves at Cessna.

You will obvously also be able to justify yourself to the CAA test flight department who have also test flown the aircraft before acceptance onto the register and who will probably say......let's stick with what has been safe and efficient for the last 50 years.

Waiting for the Avweb joke....did you hear about the guy who did some home testing of a production aircraft.

I have been involved with an aircraft and test flight. One type in current production was tested to the mid 20Kts crosswind. However, the limit that was agreed for the flight manual was 15Kt. Why?......because the flight manual is and must always be for the average pilot with average skill.

:D

Regards,

DFC

DFC

A bit patronising if FullyFlapped turns out to be an experienced pilot with a lot of time on type, and if he took the right approach, with the right frame of mind. It doesn't take a test pilot.

I have landed (on a private flight I hasten to add) with a 30G40 at 70 degrees from runway heading, in an aircraft with a demonstrated crosswind component of 17 kts. BUT (and notice it's an important but) I had several hundred hours on type. I had landed before on a huge, wide runway in slightly lighter crosswind, so I knew the capability, and I flew for a go-around. Had the conditions not been perfect in the flare I was ready with the throttles, I had accepted that I was probably going to have to climb away to take the (short, grass but into-wind) cross runway.

When I was become an FI my instructor sent me up in a 26-kt crosswind in an aircraft with a demonstrated crosswind of 12 kts. He knew it was easily capable.

Demonstrated crosswind components were never meant to be limits, or they would be called such. They are recommendations intended to show what a mediocre pilot would be able to cope with and not break the aircraft, and as a sensible limit for most commercial operations (the operations manual will make the demonstrated crosswind a mandatory limit) to give greater safety margins.

I have yet to come across an GA type that cannot be landed in winds stronger than its demonstrated component and I doubt there are many over say a year old that havent been landed at more than their demonstrated component.

Does this increase leg fatigue?

Every landing causes some fatigue, some landings cause more fatigue than others (and not only the cross wind ones), and some pilots cause a lot more fatigue in more ways than you will ever know. :D

I have yet to fly an aircraft that can not be landed or taken-off in less than the distance specified in the flight manual.

The CAA and the insurer will ignore the 50,000 previous times you landed in a 50 knot crosswind if you break the aircraft while landing in a 20 knot crosswind when the max demonstrated is 15.

----------

Life's a Beech,

Your instructor would have been guilty of manslaughter if you had killed yourself.

The point is that FullyFlapped is by definition claiming to be a test pilot and consequently will have prepared in advance a test flying programme, have appropriate test cards as well as data obtained and will have a report that because of their credibility as a test pilot will be acepted.

I have been involved in test flying for a few years but still operate under the supervision and guidance of a more experienced pilot (as well as a flight test engineer) and must submit all reports through the designated senior test pilot.

Getting away with it and living to write an email is not test flying.

Regards,

DFC

At least part of the POH is the approved AFM which includes the section on limitations. i.e. approved by the FAA or equivalent.
I was involved in a mod to the landing gear of a Pitts S-1 - RV type gear (and Haigh tailwheel) instead of the bungees. We happened to find 25 kts xwing when we did our tests so submitted that in the AFM and the response was we could either leave it as 17 kts or have the authority's TP confirm it.

I cant imagine they would - it could go horribly wrong.

So you are telling the Court that you meant to use the word "limit" but actually wrote "maximium demonstrated".

Hmmm, could end up with a product liability suite me thinks.

I would rather be defending.

X/winds can be a real problem when flying in areas with poor or no weather reporting and forecasts.

So when I get to a destination with a X/wind that exceeds the demonstrated X/wind component of the airplane I will land it if there is no alternate available....

Unless they design an airplane that I can just park over the airport and wait until the wind changes.

How much for the Authority Test Pilot? or did you bother to ask? :ooh:

Regards,

DFC

Chuck - I was wondering if you call a Pan so as to enable you to do something that would otherwise be illegal?

Chuck - I was wondering if you call a Pan so as to enable you to do something that would otherwise be illegal?

Call a Pan?

Why would I call a Pan every time I landed with a X/wind that exceeded the demonstrated X/wind of the airplane?

If it is illegal then there are thousands of us flying for a living that do it because we had no other choice but to land.

Here is a question for you...

Many years ago we were hauling fuel with a DC3 in Canada's high Arctic the weather was perfect until our last trip.

Sixty miles out of Resolute (our destination ) the FSS called us and informed us that a sudden unforcasted wind had come up and Resolute was going below VFR limits in blowing snow.

By the time we were on final for the runway the FSS gave us another update.
Visibility zero in blowing snow and the wind was 50 knots 90 degrees to the runway.

It was dark and we could see the runway approach lights and the runway lights on final approach but only dimly in the blowing snow.

What should I have done with no alternate?

Declared a Pan?

WTF good would that nonsense have done me?

I landed it with the 50 knot X/wind and the sucker just slid straight down the runway. ( As I knew it would. )

Why would you transmit a PAN at the planning stage?

No weather info for destination means an alternate is required where the weather is suitable should a landing not be possible at the desination.

Furthermore, telling everyone that you have an urgent message to transmit but do not require assisteance may not be appropriate if caught out in such a situation.

regards,

DFC

Some of the writers here have read CAR 3, the CAR 3 Flight Test Guide, and FAR Part 23 many times, and understand the deliberate choice of terminology required by those documents.

It seems to me that it would be a great benefit for others here to at least have an awareness of the content of these documents. A lot of the silly comments here (and a response requested of Cessna) could have been saved by doing the homework first!

Pilot DAR

DFC,

Thank you for the insults in your previous posts. I see that you're now a test pilot as well as having the many other areas of expertise to which you have referred over the years : what a fantastic career you must be having.

As to myself, when I'm not pretending to be a test pilot, or acting as an idiot, or making myself the subject of Avweb humour, I'm just a guy with many hours on type who can read ... hey - let's see if you can too !

Here's a verbatim quotation from my POH ...

"Demonstrated Crosswind Velocity is the velocity of the cross-wind component for which adequate control of the airplane during takeoff and landing was actually demonstrated during certification tests. The value shown is not considered to be limiting." (my emphasis).

Good luck with the test pilot phase of your long and oh-so-varied career ... :rolleyes:

FF :ok:

I slightly doubt that DFC, gross negligence maybe but manslaughter?...Hardly. If you are doing a FI course then you're already going to be reasonably experienced and dead or not the AAIB will surely note that the ultimate responsibility lay with the idiot who agreed to go up in said wind in the first place.

I learned to fly in a member of the cub family, a 1946 PA12. As a student pilot I landed in the biggest xwind I ever have, during a solo cross country. It was pretty much 20kts across the runway. I find the cub series to be good crosswind airplanes. The super cub has the one issue where if you pull flaps in you can only get so much left aileron in, because the flap handle blocks your leg which then blocks the stick.

I fly pawnees too, in the really big crosswinds I worry about dragging a wingtip because it's a low wing. But I never have. I'm also known to cheat and takeoff/land a little into the wind rather than right down the centerline when it's sporty.

-- IFMU

All I can say is that you're a braver man than I...for my taildragger check out I had to fly in 8-10knots xw (while me instructor watched me from the ground) and I have to say on a rather muddy, slippery field the prospect of doing anything stronger was not very appealing.

I could not agree more. I wasnt being serious - sorry a bit of a strange sense of humour.

I was seeking to make the point that IF it was "illegal" to land with a cross wind over that demonstrated then presumably the pilot would have to declare a pan or mayday because he could reasonably expect the uc to collapse on landing.

For me the fact remains that these days with such a high risk of product liability etc if the lawyers had intended to say LIMITING then I think they would have managed to use that word in the POH - if the word LIMITING is not used then I think it is entirely reasonable for the pilot, insureres, CAA and any one else who cares to comment to consider it to be demonstrated NOT limiting.

In short, I dont understand and you havent convinced me DFC, why you believe otherewise?

To be fair some of the authority tests pilots are not all that. Ask my neighbour who handed over his turboprop converted glassair for test flying and had it left as pile of parts at Conington!!!

Here we are dealing with fact. Something that has been demonstrated, has been checked and which has been certified and something that the average pilot can repeat on a consistent basis.

That is opinion or speculation and is not based on any calculation demonstration or result.

What is says it that adequate control exists at the max demonstrated crosswind. It may or it may not exist above that figure.....if you want to try and find out, don't blame us if the aircraft breaks or you hurt yourself.

Your insurance company will expect you to take reasonable care. Test flying is prohibited by most policies.

Regards,

DFC

Quote:

---

The value shown is not considered to be limiting.

---

DFC - so why would the lawyers add this in the POH?

An aircraft I fly is placarded to say I MUST NOT perform certain aerobatics if certain conditions are not met.

I can find no placard to say I MUST not land if the cross wind component is above a certain figure.

Why is there a placard for the first (and I might never fly aeros in the aircraft) but not for the second, given at the very least I am hopefully going to land after every flight.

Fuji,

Do you know that the legal department added in that piece?

The placards in your aircraft are giverned by regulation - the certification standard and the mandatory ones will be listed in the Type Certificate Data Sheet.

You will find all the limits on the Type Certificate Dats Sheet.

You will not find the Stall Speeds there. Do you think that they are limiting in any way? :)

You will not find that airfeild performance figures there. Do they limit you in any way?

As I said near the start of the debate. Feel free to be a test pilot if you want. Check that test flying is permitted by the insurance policy because valid insurance is mandatory.

You might also like to check the legal conditions required for test flying especially the ones regarding the carriage of observers etc etc.

Regards,

DFC

Are you seriously suggesting that an aircraft manufacturer's lawyers - in the USA of all places - would allow speculation or unproven opinion to form part of a POH?

Do you honestly think that nobody at Cessna would have flown the aircraft at higher x-wind speeds than the MDCV before making this statement in the POH ?

Honestly ? And you call me an idiot ?

FF :ok:

Do you know that the legal department added in that piece?

Do you know they didnt? And if they didnt you bet they reviewed it. And if they didnt review it then they had better look out.

and 2wit, as you know, no one is saying you should NOT stall most GA types, otherwise that would be one less task for the flight trainers.

.. .. .. and so back to which, since it would seem clear most manufacturers

are able to grasp the use of plain English by virtue of being happy to liberally sprinkle the POH with "limiting" and "prohibited" and such other clear wording I shall hold on to my belief that if they wished to limit me to their demonstrated component they would have said so - and that shall remain my defense!

Ok, As it appears that only DFC has really done his homework here, and understands where the term "demonstrated" originated, here's the standard:

3.145 Directional stability and control
(a) There shall be no uncontrollable looping tendency in 90-degree cross winds up to a velocity equal to 0.2 Vs0 at any speed at which the aircraft may be expected to be operated upon the ground or water.
(b) All landplanes shall be demonstrated to be satisfactorily controllable with no exceptional degree of skill or alertness on the part of the pilot in power-off landings at normal landing speed and during which brakes or engine power are not used to maintain a straight path.
(c) Means shall be provided for adequate directional control during taxiing.

So the aircraft manufacturer's lawyers are going to go to court and say "our test pilots did that, and here's the report." If the test pilots did more, and you can bet that they did, the manufacturer is not going to tell you that. There are lots of things they are not going to tel you.

Cessna used to produce a document called "Getting the maximum performance from a Cessna 150". I saw it once. Try to get a copy now!

My Cessna has a stated demonstrated crosswind value, which I'm sure meets the aforementioned standard. It also has an STC'd STOL kit, which very much changes low speed handling, and stall speed. That installation does not change the demonstrated crosswind capability value though, as no revised value is provided with the kit. (No Flight Manual Supplement or placard is provided, and that's the only way to convey changed information).

Manufacturer's and writers of design standards know that some pilots have more skill than others. They must account for the lowest common denominator of pilot skill sets in the standards. Hence demonstrating that the average skill set is enough to safely control the plane.

Sometimes when I have done modification design complaince evaluation flying for Transport Canada (I'm carefully not calling it test flying, Im not going to start that debate!) I wonder to myself if I am properly simulating average skill during cross wind work. If I apply a lot of effort to seeing what the aircraft can do, I may have gone beyond a demonstration of average skill.

Pilot DAR

Limits and otherwise
 

Look, this is all much simpler than is being argued.
The design approval of an aeroplane requires certain facts to be established. Hopefully someone will find the actual design regulations and link them here, it has been found before but some time ago.
The Demonstrated Crosswind Component is not an actual flown exercise but a mathmatical calculation based on designed control available. It is generally understood that this calculation demonstrates that an average pilot in reasonable practice should be able to control the aircraft safely when landing. The italics are not the regulation but how they might reasonably be interpreted. However these calculations are only one part of a scenario where many other factors may be dominent such as pilot ability and other considerations pertaining at the time. This is usually the case with light aircaft and therefore it would be impossible to define a limit. I'm sure that there are light aircraft with a crosswind defined limit, just the same.
A limit is normally applied to larger heavy aircraft (although not only) when beyond such a limit, control of the aircraft is unlikely irrespective of the pilots ability. This could be say a limit on the maximum angle of bank during landing owing to the fact that the wing tip, engine nacelle or propellor could strike the ground. There will be various reasons but i'm sure it is obvious that with the above restrictions the pilots choices are 'limited' and so therefore is the maximum crosswind.

DAR,

Is there an equivalent standard for "x-wind LIMIT" ?

I think you're missing the point. The definition of the word "demonstrated" is not the issue : what is being argued over is whether operating an aircraft beyond its demonstrated x-wind value is illegal by virtue of the fact that to do so instantly makes you a test-pilot and therefore invalidates your insurance (and makes your under-carriage fall off, evidently ...)

My argument is that if Mr. Cessna says that the MDCV "is not considered to be limiting", then he's saying that because his designers and test pilots have already proven this to be the case.

If I attempt to land with a ridiculous amount of x-wind and the wheels snap off, I'd expect to have a problem with my insurers. However, if the same thing happened a couple of knots over the MDCV, with the protection of that statement in my POH I'd be quite happy to pursue a claim.

In short, if they meant "limit", they'd say so ...

FF :ok:

DAR and FF

Actually FF I think it was a good post but for a different reason.

It brings home the key point on an interesting and very old debate.

For commercial ops it can be assumed that all pilots will perform to a given standard. In short a limit can be imposed because there is a reasonable possibility you will bend it if you go beyond the limit.

In GA the product liability lawyers learnt long ago that many of their customers really havent got a clue what they are doing. Consequently they are not going to tell you what the limit is, becasue many will try it and regret they did. However, what they will tell you is what a reasonably ham fisted pilot is likely to be able to get away with.

So as my final contribution on this one, I think how the number is derived is well known (to those on here at any rate), and I have seen absolutely nothing to convince me that it is in any way intended to be a limit.

(Sorry to disappoint you DFC - I respect the points you have made, I just dont agree with them)

Homeguard,
I disagree. My understanding is that the demonstrated crosswind is simply that which was observed by the certifying authority during flight testing for certification. I'm sure there are certain minimum crosswind capabilities that are mathematically built in at design time, like the FAA required 0.2Vso for example (something like that anyway). But I don't believe the demonstrated one is a limit unless somebody decides to make it so (A flying club's regulations for example). I certainly don't suggest anybody tries it, but I am sure I am not alone, I am sure there are many PA28 and C152 pilots out there who have landed in crosswinds several knots in excess of the demonstrated without any difficulties.

Now the PA17 on the other hand...well my limit is somewhat lower :\

There is little mystery about how this number is determined:

AC23-8B FLIGHT TEST GUIDE FOR CERTIFICATION OF PART 23 AIRPLANES.
107. SECTION 23.233 DIRECTIONAL STABILITY AND CONTROL.
a. Explanation.
(1) Crosswind. This regulation establishes the minimum value of crosswind that must be demonstrated. Since the minimum required value may be far less than the actual capability of the airplane, higher values may be tested at the option of the applicant. The highest 90-degree crosswind component tested satisfactorily should be put in the AFM as performance information. If a demonstrated crosswind is found limiting, it has to be introduced in Section 2 of the AFM.
...
b. Procedures.
(1) Crosswind.
(a) The airplane should be operated throughout its approved loading envelope at gradually increasing values of crosswind component until a crosswind equivalent to 0.2 VSO is reached. All approved takeoff and landing configurations should be evaluated. Higher crosswind values may be evaluated at the discretion of the test pilot for AFM inclusion.

It would be difficult to be more explicit about whether the vaalue is limiting or not, wouldn't it?

I don't want to argue the toss about the legality (or otherwise) of landing at above the "Demonstrated" figure, but the above value rather intrigues me. It appears to be very pessimistic even by the standards of "average" pilots.
In my machines case this is barely 5kts, and would hardly be noticeable. In practice (and backed up by some of the claims on here) a value of 0.3 - 0.4 would be more realistic. Or in the case of Chuck Ellsworth's Dakota 1.0!!
I really wonder if I shouldn't give up flying until such time as scientists can control the weather, or every airfield has multiple runways.

I understand that the 0.2Vso limit is only the minimum using only aerodynamic controls, I don't think this infers anything else.

Higher values maybe quoted if demonstrated. Where those higher values require the use of specific techniques, braking or engines to maintain control, those technique will be described in the flight manual.

Where in the flght manual does it say that you have to hold a licence to fly the aircraft?

Indeed. And guess what the imposed crosswinf limit will be!!

bookworm has posted a very valuable quote;

This places it in the same category as airfield performance.

What will your insurance company say if you run into the hedge at the end of a 499m strip when the flight manual says you need 500m in the conditions?

Anyone who wants to use a crosswind higher than the manufacturer has demonstrated as being safe can do so any time they want. However, they simply have to be aware that if their insurance policy says no test flying then they are not covered.

They could always stand up in court after the accident and proudly tell the court that despite the damamged aircraft being evidence to the contrary, they are a pilot of above average ability........to the sound of "arrogant to$$3r" from everyone present. :E

----------

Pilot DAR,

Love it, Must remember that in future. :ok:

Regards,

DFC

Is Beagle still about?
He IS a test pilot isn't he? sounds like a good source for an authroritive answer.
I've managed 28G38 at 80deg in a C150. With the instant wind at the top of that as I came over the threshold.
Piece of cake, and I'm sure no problem for the insurers if you come into difficulties..

It may do but in reality take off performance data is not of the same nature as crosswind landing data...I remember reading an accident report ages ago which involved (I think) a King Air which crashed while landing in a crosswind that was higher than its demo limit. The accident report clearly stated that this did not constitute any breaking of regulations and that the wind was 'acceptable' to the crew because the aircraft had no absolute crosswind limit. Had the accident involved them landing on a runway which was too short for the book figures then the situation regarding the observation of aircraft performance data would have been rather different....

I said I wasnt going to post again - and it really really is my last, but I always worry about insurance issues.

Anyway I emailed my insurers to ask whether they would settle a claim if the aircraft landed in a cross wind more than the demonstrated cross wind component in the POH and in consequence was damaged.

They said they would.

In fact they have just 'phoned to say they wondered whether an accident had actually occurred. I told them it had not but thanked them for their concern. We chatted and I pointed them to this thread which he had actually been reading. He laughed, said so far as they were concerned the whole thing was totally ridiculous and they had all had a chuckle. He made one or two other amusing comments.

It has put my mind at rest so far as the insurance issue was concerned.

I appreciate other insureres may take a different view.

Bookworm :

Absolutely.

Anyway, that's me out of this thread until/if Cessna reply to the letter I've sent. It's absolutely pointless trying to debate with someone like DFC who is willing to only quote the parts of a post which suit his purpose whilst ignoring the rest :-

Mass weapons of destruction in 45 mins, anyone ? :=:yuk::ugh:

However, if anyone has any actual knowledge of any prosecution where a pilot has been done for exceeding a demo'd x-wind value - in an aircraft where the POH does NOT state the value to be limiting - I'd be interested in hearing it ?

Edited to add : Fuji, thanks for doing that. You will have set a lot of people's minds at rest - good for you !

FF :ok:

Did they phoned you to say it was ok, or did they emailed you back to say it's ok ? Just make sure you have a written proof :E

Sternone

Yep, been there, done that - all in writing of course.

Still, thanks for the reminder to everyone.

Fuji, thanks for posting that which was what I was originally trying to get at. Mine have said the same, but as with many things in aviation the facts (as opposed to the folklore) appears to have got long since lost amongst the clubhouse bullsh!t, along with IMC-rating approach minima I presume...