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When PA28 met Mr xwind

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When PA28 met Mr xwind

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Old 3rd Oct 2004, 08:22
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When PA28 met Mr xwind

Today I cancelled a flight to Zeeland despite the weather being good all the way there and back. The only problem was this TAF:

EGGW 030425Z 031206 22010KT 9999 SCT025 BECMG 1619 20017G30KT ...

Essentially I would have been happy with it, apart from the winds towards the end and it set me thinking. This is not exclusively for the PA28 but I'll use it as an example. With a crosswind limitation of 17kts would you actually land it with that windspeed, if anyone's done it what was it like?

If it's not just a pure crosswind but say a 30kt wind with a 15kt xwind component would you fly? and if so at what sort of overall windspeed would you not?

Finally, the gusts, if your actual wind speed is within limits but your gusts put you just above crosswind limits (say 1 - 2kt) should that automatically send the alarm bells ringing?

I am not looking for some hard and fast figures just some general advise so that I can start building up my personal crosswind limitations so I won't have to worry if push comes to shove one day.
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Old 3rd Oct 2004, 09:05
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Never mind what the academic crosswind component is, are YOU happy to land in those conditions given your experience and ability!

It goes without saying that you should be operating within the limits defined in the Flight Manual or POH.

Find a really good flying instructor and go practice with him until you feel totally competent in said crosswinds. That said the PA28 is an excellent aircraft in crosswind conditions if flown correctly.

Safe flying!
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Old 3rd Oct 2004, 10:54
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I'm sticking my neck way out here, but as I understand it, the figure in the POH is the "demonstrated" crosswind component, not the actual maximum.

I guess if you are an ace pilot you can do better than this.

I was taken out, as a newbie student pilot and have had to land in the "demonstrated" maximum for a C150 which is 15 knots. It seemed to be OK for me, it was just a function of your wing down technique.

More expereinced pilots please feel free to contradict and enlighten me.
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Old 3rd Oct 2004, 11:05
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More expereinced pilots ...
Whilst training I went out in a C152 in a 14 knot crosswind (dual), a bit gusty but not desperately so. Several of my landings were fine ... but one attempt was so hairy that it visibly frightened the instructor. (We did the rest of the hour without carb heat, to give him a little more power if he needed to do another go-around a few feet above the ground whilst pointing sideways across the runway at a very strange attitude.)

The club has a 10 knot limit for solo hire, so if I now wanted to practice 17 knot crosswind landings I'd have to take an instructor with me. Some of the limitations on solo hire in the flying order book give an element of discretion to the authorising instructor, this one doesn't.
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Old 3rd Oct 2004, 11:07
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it is all down to technique and the point you run out of rudder authority!

I regularily land my 152 in 25kts crosswinds as our farm strip only has one runway. But that is a result of several hundred hours in that particular aircraft and practice of the appropraite technique.
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Old 3rd Oct 2004, 13:19
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Another rule of thumb is the total wind versus the clean stalling speed.

Dick Collins (or someone similar) wrote that when the wind gets above 50% of the clean stalling speed, you ought to start thinking about it.

In a PA28, that would be circa 27kts.

Personally, I wouldn't fly in those conditions in a PA28, as much for comfort as any safety considerations, it would probably be quite turbulent and uncomfortable for the pax.
 
Old 3rd Oct 2004, 14:09
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And I would add not just experience and ability but currency is very relevant as well.
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Old 3rd Oct 2004, 15:47
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What about the position regarding insurance?

If you had a prang landing in a 20kt cross-wind, would the insurance have a right not to pay out?
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Old 3rd Oct 2004, 21:44
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If you had a prang landing in a 20kt cross-wind, would the insurance have a right not to pay out?
Unlikely that they would refuse to pay out.

(Now don't all go out and prang your aeroplanes in crosswinds you can not cope with and think you can get the money from me is they do refuse to pay!)

Going back to the initial question. The figure is indeed a demonstrated Xwind not a limit as such.

The strong and gusty conditions today were very much associated with worse weather to come.

To go and fly away from that weather and having to come back towards it a few hours later means you have to take a view on how certain you are that the fronts move at the forecast speed.

That and the fact that there was worse to come would be more of a factor to base my decision on than the windstrength per se.

FD
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Old 3rd Oct 2004, 22:09
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As has been said, it is all down to how you feel about it. I learnt to fly at Cardiff, which has a built in Xwind. The type of aircraft has quite a lot to do with it as well. For example, I have landed a PA-38 in a 28kt Xwind without any problems at all. I used to fly a Rockwell 112A, and the Max demonstrated Xwind is stated at 17Kts (I seem to remember) but I found that anything above about 11 was a REAL handful. I have never really had too much of a problem with PA-28's, but I guess that it's up to you. If you don't feel comfortable, don't do it. I, however have always found the 'challanging' landings are the smoothest because I have been concentrating the hardest. The ones where you have 2km of runway and no wind to think about are the ones I most often thump on, just because I'm not really concentrating on the job in hand. Why not go up with an instructor next time the wind gets up, and give it a go. I bet that you'll be surprised at just how much of a Xwind you can handle.
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Old 4th Oct 2004, 14:10
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We did the rest of the hour without carb heat, to give him a little more power if he needed to do another go-around
This is not the way to do things - if you put the carb heat to cold either as you advance the power or as you pass 200' (or similar point) you have full power anyway, leaving carb heat off the whole time can result in carb. icing - which of course is why we HAVE a carb heat system, and if THAT happens you will definitely NOT get full power.
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Old 4th Oct 2004, 16:58
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Never mind what the academic crosswind component is, are YOU happy to land in those conditions given your experience and ability!
I agree.

What about the position regarding insurance? If you had a prang landing in a 20kt cross-wind, would the insurance have a right not to pay out?
Unless there is an express exclusion in your policy (very unlikely), I do not believe that insurer would be able to avoid an indemnity on the basis that you exceeded the demonstrated crosswind component in the POH. As stated above, it is not a manufacturer's limitation. Arguably it is imprudent to exceed POH figures, but imprudence is not usually a valid ground for avoiding liability under a insurance policy.

Of interest, there is an article in Flying Magazine's book I Learned About Flying From That, concerning an insurer's attempt to prosecute a subrogation claim against a pilot who crashed a 'plane while practicing crosswind circuits. The insurer's argument (which I'm happy to say was rejected by the Court) was that crosswind landings are inherently dangerous and should never be attempted except in an emergency.
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Old 4th Oct 2004, 17:04
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if you put the carb heat to cold either as you advance the power or as you pass 200' (or similar point) you have full power anyway
Indeed we put the carb heat to cold at about 50', instead of leaving it hot for the landing, sorry if I gave the impression that we left it cold for the entire descent.
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Old 5th Oct 2004, 12:28
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In my experience, cross winds up to the "max demonstrated...." don't pose to much of a problem. I'd use less flap though.

However, only fly in what you feel comfortable flying in. I used to be paranoid of crosswinds as a student, becasue every bleedin day we had a 10kt+ 90° crosswind, which frankly stopped me going solo till about 25 hrs. Now I enjoy the challenge, though I was surprised on my last flight to note that my left rudder pedal was nearly in the firewall trying to keep that centreline A touch more speed may have helped.....

I use wing down as well. I crab in on final, then "when it looks right" transition to wing down...............
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Old 5th Oct 2004, 12:58
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Quote:

Indeed we put the carb heat to cold at about 50', instead of leaving it hot for the landing, sorry if I gave the impression that we left it cold for the entire descent.

A recent AAIB report

http://www.dft.gov.uk/stellent/group...ty_028745.hcsp

referred to the C152 Information Manual stating that the procedure was to leave carb heat on until landing, this differs from the advice in the relevant AIC and Safety Sense leaflet. I am away from a copy of the C152 POH to check this.
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Old 5th Oct 2004, 13:22
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No-one has mentioned the accuracy of the quoted wind. At a large airport, you will be given the 2-minute mean (unless it is qualified as an "instant" wind check). Gusts are not reported unless they exceed the mean by 10 knots because the wind is never (ok rarely) constant. At small fields, with A/G radio, you may be told a wind is 10 knots gusting 15, which at least tells you that the operator doesn't know how to quote windspeed.

Also the wind is being quoted 10 metres above the ground at a different part of the airfield to the bit of runway you are trying to land on.

All this means that the wind quoted is at best a guide, and remember that a forecast it is just that; a forecast.

When you are landing, particularly in a taildragger, what matters is can you arrest the drift before you put the wheels down.
If you can, then land, if not, then go-around. There are some exceptions to this such as taildraggers with skids and no brakes where the limiting factor is crosswind towards the end of the landing roll.

The quoted wind is a guide. The windsocks are better because you see the information quicker, but best of all are the blades of grass on, or either side of the runway, and how the aircraft itself is handling.

One trap to beware of is that some A/G operators seem to exagerate the wind by quoting the highest peak they have seen. The danger then is that you might believe that you can handle the quoted crosswind component, rather than the lower value you actually landed in. We had one member of our group who thought he had successfully landed a light taildragger with more than a 20 knot crosswind component because of this dangerous practice. Thank goodness he didn't try subsequently when the crosswind was correctly quoted as over 20 knots.

Currency is also a factor to consider. Just because you could handle a 20 knot crosswind in wonderplane A last year, doesn't mean you can today, if you haven't flown that type for a while.
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Old 5th Oct 2004, 13:28
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As far as I am aware the max demonstrated X wind for a PA28 is 17mph........which is 15Kt.

As said this is simply the maximum crosswind that a test pilot operated the aircraft to during flight testing.........everyone is entitled to become their own test pilot and try a higher figure but I bet the insurance will have a get out when it comes to test flying so perhaps one should pay the loading that the insurance company will put on the policy prior to it's intentional use for test flying.

Getting caught out is something different!!

Remember that when it comes to gusts, they are only reported when the reach 10Kt above the mean.

Thus 180/15 could be 180/15 or it could be 180/15 gust 24.....one has to look at the bigger picture or call for an instant wind report.

Also the variations in wind direction have to be quite large before they are reported in the routine reports so being on the limits cand be fraught with danger for the unwary.

regards,

DFC
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Old 5th Oct 2004, 16:54
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I think that you will find it is 17KIAS, which is 19.55MPH or 20MPH, when rounded up.
 
Old 5th Oct 2004, 17:05
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Final 3 Greens,

You are correct. It is indeed 17Kt for the PA28.

Regards,

DFC
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Old 5th Oct 2004, 18:53
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just back in from Kemble where I landed my 152 with a demonstrated crosswind of 15kts in a 33kt headwind with a 20kt crosswind component. Nothing fell off, does this mean the demomstrated crosswind is now 20kt?

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