Found my personal X-Wind Component

[N74DV]

Yesterday I have realized what my personal limit is for crosswind component in our BC12D. 13 knots.

had to land on runway 22 at FFZ and wind was 130@13kts. 13 knots direct at 90 degrees.

I knew it was going to be the stiffest crosswind I had landed in when I saw how much crab I had on final just to keep in line with the extended centerline.... holy smokes I felt like I was looking out the passengers side window.

I decided I'd keep my speed up.. about 65mph, and "fly it on". Once I got to about 5' off and began to slow a bit I really noticed how much left aileron I was requiring. Not at the stops but damn close. It felt like any more and I'd be dragging the wing. I had full right rudder and was prepared to get on the right brake once the right wheel touched.

Managed to plant the left main and kept the power at high idle and did my best to keep her straight until the right main came down at which point I chopped throttle held full left aileron and sucked the wheel all the way back.

Full right rudder and even some right brake and it was barely able to keep from swinging left.

Yep... I'll not be trying any more of that again if I can help it. I'll stick to 10kts component or less.

That was the most exciting landing in our Tcraft I've ever done.... the scariest as well. Now I can look back at it and laugh a bit. I must have looked like a whacko in that cockpit with my elbows and ankles flailing like a fish out of water.

[dennispip]

Re: Found my personal X-Wind Component

Probably was on hard surface with several hundred spectators viewing!! If it was a steady wind it would be one thing. Throw in gusts to 25K and it would be time for a different destination.

[VictorBravo]

Re: Found my personal X-Wind Component

There is a geometric, aerodynamic and/or mathematical maximum amount of crosswind, in which the Taylorcraft design can continue straight down a runway at a given speed, with a given amount of usable brake, full rudder, etc. I have no idea whether the engineers calculated that out, or whether they just had the test pilots go out and see what they "felt" was certifiable. Forrest???

For whatever my limited amount of experience is worth, I think a 20 or 25mph sideways gust hitting an airplane that is only traveling at 40 mph is likely un-recoverable (in terms of keeping the airplane moving straight down the runway), no matter how much brake you have.

The leverage that the long Taylorcraft tailboom can apply with a side load on the fin is very large, plus the rudder itself is not enormous (and no aerodynamic balance to boot). The "tail arm" between main wheels and tailwheel is probably 2.5 to three times longer than the wheel track, so the leverage applied by heavy braking on one side can easily be overcome by a smaller push on the tail.

Another factor is that a strong gust on the side of the tail can "stall" the fin/rudder by creating an airflow separation on the downwind side of the fin. This of course creates a lot of drag, in the downwind (groundloop)direction, worsening the condition for an already maxed out rudder. This phenomenon is worsened with "flat plate" tail surfaces (no airfoil) on all the old tube airplanes. (This is why Chris Heintz uses an all-flying rudder on his CH701/750/801 airplanes and can thus have a smaller surface with better Xwind components)

The built-in mitigating help that CG Taylor thoughtfully provided us with is that the T-craft can get down to 38 or 40 MPH, which means that if you have a 20 or 25 mph crosswind you can land directly across many runways at 15 -20 MPH groundspeed, or land at an angle across the runway... creating an effectively less crosswind and still lowering your groundspeed.

Although high-timers like Forrest and several others can feel free to correct me on this, I believe that landing across or angled on a runway is an excellent tool that is not nearly used enough. Most importantly, if you are doing a hard crosswind landing and you choose to angle across the runway as much as possible, if a gust comes after you and overpowers the airplane you will have far less of a groundloop (angle of heading change) and less inertia on the tail. You also would possibly have less chance of dragging the downwind wingtip in my opinion.

I've always had a very quick willingness to land in a non-standard manner and to heck with anyone who didn't like it. This comes from flying gliders and self-insuring most of my airplanes as well

Sorry for the wild rant, but we always gotta remember that we're flying a certified ultralight airplane with a 6 or 7 pound wing loading that is very susceptible to gusts. Landing at an angle when needed reduces the groundspeed, reduces the effective Xwind, increases the available aerodynamic control force, and reduces the inertia of the tail in a groundl... ( I mean "swing" for Rob Lees)

[Frank DeBartolo]

Re: Found my personal X-Wind Component

The other day, the wind was 15K gusting to 20K. We have two runways one is paved--Runway 15, however taildraggers typically land on the grass to the side of the runway. The X wind component on runway 15 was 30 degrees. The other runway, runway 20 is grass and the X wind component was 80 degrees. I landed on Runway 15 on the grass twice and although it was a handfull, it was doable. I tried Runway 20 twice and twice went around from just above flare altitude. The thing I noticed as I got close to the flare was the high amount of bank to stop the drift and high amount of rudder to hold the airplane straight. I never did get it totally straight on Runway 20. The thing I noticed was the more violent up and down oscillations during the gusts as I was in the crosswind slip. I did not land on Runway 20 but tried it twice to see if I could. There were up and down oscillations during the gusts in the 30 degree X wind but not as severe as in the 80 degree X wind. My guess is that the degree of bank deflected the vertical component of lift too much to the horizontal and the difference in the two approaches was significant. The two take offs and landings on Runway 15 was not that tough but Runway 20 with 80 degree X wind with gusts was more than I wanted to tackle.

Frank D
N43684

[Ragwing nut]

Re: Found my personal X-Wind Component

I actually exceeded it crosswind component once when I still had the F-21. Took off at our airport when was straight down the runway. When to another airport and had the same gusts except they were 90* to pavement. I know they wer 20k plus. If I did not have to land I never would have. I had it full lock to lock and was just enough to keep it going down the runway straight, however when i tried to land, it was so sideways, it would only hop. Second attempt went to the grass and slid it in. I could not relax the aileron or it would pick up the wing. If I had not been in the F-21 with excess power and Cleveland brakes, i would have for sure wrecked the airplane. After that, I swore off flying a kite in any major wind.

[Forrest Barber]

Re: Found my personal X-Wind Component

I am sure I posted this before, many times I have landed across a runway on a diagonal, sometimes in a field next to the runway. I "demonstrated" the F-19 prototype to the FAA with a 21K direct cross wind. Of course we could not use that in the manual , I always liked 25% of stall speed . By the way the reason for not using the "demonstrated" 21K ; was and THIS IS THEIR words not mine . I had used "exceptional piloting ability" ; bull I was just lucky on two landings and the third just worked out, this was all on a Sod runway. I have mentioned in the past that I use wheel landings a lot and for the nay sayers that mention the tail has to go down sometime, I agree! I have "flown" the ship on its wheels to the tie-down area , pointed her into the wind, set the brakes, lowered the tail and hoped somebody would come out and help position her into the tie downs.....Sod & hard surface.

[jim cooper]

Re: Found my personal X-Wind Component

Flying light planes, Champs, T-Craft, Cubs in winds over 12-15 mph seems like work to me. Its rough. Your getting thrashed around, bumping your head, etc. No joy! I HAVE landed in X winds up to 15, never 20(in a taildragger) Everything had better be just right, brakes GOOD especially! I'd go in a Bonanza or a Mooney or even a Stinson 108 (maybe). My T-Craft stays on the ground.JC

[Len Petterson]

Re: Found my personal X-Wind Component

In the Canadian Flight supplement pupliched by the Transport Canada is a
Maximum crosswind chart based on 20% of stall speed.
My book is in the plane or I would copy a the page for the website.
Mine stalls at 42MPH IAS,20% = 8 Mph windspeed at 90 Deg to the runway.
at 45 deg to the runway it would be 16 Mph wind speed.
I used it from the begining and it works. I belive it is the Canadian guidlines for aircraft certification.
I failed to land on a Crossed off runway one time,(What was into the wind but the grass was growing trough the payvment) with a not so pleasant result. The O-Sh-t factor went high!
Sometime we have to through rules out the window, too save the bacon.
Len