Crosswind Component

[170C]

Reading an article in one of the aviation mag's & it pointed out how important it is to know the xwind component of ones airplane. I suppose it depends upon which model of a 170 one has, but since I have a converted 172 the data, if it exists, on a 56 172 would not be pertinent to a conventional geared one. Any thoughts on what a conventional gear 172 xwind conponent might be?

[paulbritton88]

I believe most of the 172 manuals reference 15 knots.
The 1978 manual says something to the effect of "15 kts can be handled with average pilot technique."

The only way you'll really know what you and your aircraft can handle is to get out and practice.

[Bruce Fenstermacher]

Why is it important to know the book limits, specially after the experience you have in your plane Frank. You already know what your comfort limits are and in most cases your comfort limit (or pilot skill) will be a lower limit. Or said another way I doubt your comfort level exceeds the capability of the airframe.

Most cross-wind limits are not limits at all. But demonstrated numbers. Meaning somewhere someplace someone demonstrated the aircraft could be controlled to that cross-wind component number. It is not a limit.

Oh I suppose it might be nice if I was getting in to a new aircraft and I was about to take off and had to land on a runway which had a high cross-wind at the time, to know what the max cross-wind component was, and it is nice to know info when asked on a check ride. It might also be nice to know if I was a green pilot what kind of number I might work towards for a comfort level.

[170C]

Bruce, you make a valid point! I was just curious what the "demonstrated" value ""might"" be. Unfortunately I don't have a specific wind speed at which I don't attempt a landing. I know I am not comfortable at direct crosswinds, but just don't know that I can say its at ____ mph. Of course I like any wind, on landing, to be right down the runway And when flying I want it pushing we along at GREEN SPEED

[bagarre]

Demonstrated crosswind in my '52 170 was 20 gusting 30 mph (North/South runway and winds were dead out of the West)
This was during my tailwheel training a few years ago with my instructor and I haven't tried it since.

I remember it was more of a challenge to taxi than it was to land tho. It's just unnerving to line up on final with the runway out the passenger window.

These airplanes are capable of crosswinds WAY over my comfort level but, I've never run out of rudder when wheel landing.

The Cessna 170 book has a good writeup on this subject too.

-David

[GAHorn]

...... when flying I want it pushing we along at GREEN SPEED

Just don't let a cross wind make you RED!

Line up on final at your threshold crossing speed, put your windward wing down and put in the opposite rudder to align the nose with the runway. If you can't keep the fuselage aligned with the runway centerline......its too much crosswind.
More important than crosswinds.....are tailwinds on takeoff or landing...AVOID them.
Ten knots are the max for most airplanes....but ANY, can wreck your day, especially in a
taildragger.

[JHKeeton171]

Frank I owned a converted 1956 172 with the same gear conversion STC that you have, and I believe the "demonstrated x-wind component" was 0. Meaning they did not, nor were required, to demonstrate any performance numbers, just structural integrity and "no adverse effects." What little STC paper work I ever saw, never addressed any performance or number changes at all. Now marketing literature might be something different. Since there was no flight manual supplement I think it was implied to continue using the 172 handbook numbers. I don't even think the Horton STOL kit changed any numbers or required the airspeed indicator markings to be changed, even though the stall numbers did change somewhat. Also suspect Vx and Vy were a little different with the wing leading edge, gap strips and wing tip changes, but I didn't do any flight testing to confirm. Never saw a flight manual supplement for that mod either, just used the 172 handbook numbers.

[Claude172TD]

As the current owner of JHKeeton171's 170C (thanks again Jim), and a current C-130 instructor pilot, Bruce and George's comments are spot on! Exceeding any of the published speeds simply makes you a test pilot and that's not necessarily a bad thing, but you stick your neck out a little further with every knot.

I don't think think the Horton kit installed on my airplane changes any of the published speeds, it merely "enhances the low speed handling characteristics". Now the drooped leading edges and wingtips certainly allow us to fly slower than the factory published stall speeds, but Horton doesn't publish the new speeds because of the test flight expense and potential liability. With that being said, think about this: if the the actual stall speed is reduced by 10% or about 5 knots, what effect does that reduced airflow over the rudder have on rudder effectiveness ( the ability to point the nose where you want it)? While it is difficult for a simpleton like me to calculate, the rudder is most certainly less effective at the lower speed and would therefore give you a lower maximum crosswind component (probably only one or two knots if you were flying at the lower speed for landing).

I have personally landed a Herk in 45K gusting 65K at 60 degrees off the runway heading. Per the book, that is outside the "recommended" crosswind area on the charts, but I had to get the airplane on the ground just the same. Considering the conditions, the landing was not to shabby, if I may say so myself, but it required full rudder and aileron to stay coordinated and counter a gust as I began the flare. I like to crab on extended final to see and feel what the wind is doing to me and then transition to a cross controlled short final (inside a 1/2 mile). Like George said, if you can't point the nose on short final, go around!

I have landed my 170C in 10G17Kts direct cross and was working my tail off! And yes, it was even harder to taxi.

I am of the opinion that the published max demonstrated crosswind is an excellent guide to follow even after you have demonstrated mastery of your aircraft. Those factory test pilots are hard to beat! And even then, your superior airmanship will only allow you to bend the laws of physics and aerodynamics so far, but not break them ( and hopefully not your super sweet 170C)!

Claude

[ginbug92b]

Sounds like the time we landed at Lajes with 1 engine out in the C130. Was darn near looking out the pilots side window at the runway on final.

[Bill Hart]

Yep, sounds like Lajes. Seems like there was always a Nast X wind there.

[Claude172TD]

Very good guess and plausible but no. I have seen winds in excess of 75 kts with severe mechanical turbulence from the "mountain" to the southwest at Lajes. But it's an island destination, what are you going to do, man up or divert to the Atlantic Ocean?

On my soapbox for a moment; the thing that ticks me off is that I cannot do crosswind landings with a student aircraft commander if the crosswind is over 18 or so knots. So, the first time they experience winds like that, they are on their own with a whistlebritches Lt in the right seat and very little experience to draw from. I'm just saying.

In my example it was Kabul, Afghanistan. Also infamous for nasty winds and turbulence being located in a mountain bowl. Don't go there (unless Uncle Sam tells you too or you really need the money, of course).

Claude