wind variable

[paulp]

Howdy Tribe.

Hope everyone had a great Christmas. I had a very interesting experience today @ controlled Airport. I made a call about 10 miles out and the controllor advised that the active was 17 but with the winds being variable, I had my choice of 17 or 35. Since I was approaching from the Southeast and 35 has a right pattern I inquired about a modified base to 35. The tower said call 2 mi out. I called and was cleared for an extended right base for landing 35. I inguired about the wind and was advised it was still variable @ 5-6 Kts and I should advise when turning final. Turned on final and made the call.

All was well until just after the flair. That variable wind I mentioned earlier-well, it varied!!!!! Just before touchdown I added a little right rudder and the nose moved to the left and without thinking(which is common for me) I added some more right rudder and the nose moved a WHOLE BUNCH to the left and the nose came up! Now, I'm 45 deg off the center line and nose up and thinking broken rudder cable. Then an old instructor's advice hit me-Never make a down wind landing in a light tail wheel airplane because the rudder inputs may become reversed.( funny how you can cover so much ground in your mind in such a short span of time.) Anyway, I figured what the hell, I'm in the neighborhood-try the left rudder because at this point it can't get any worse-Low and behold about 1/2 pedel of left rudder and she straightened out and dropped in almost perfect!!! I taxied to an off ramp and called ground and 5 min later the fuel truck is in front of me and I'm telling the ramp boy to top off the header with 100LL and that I would be in the coffee shop. I order a cup and as the girl went to get my coffee, an elderly gentlemen set down next to me said that he had just observed my landing. I commented that it got real interesting just before touchdown. He laughed and said that must have been your first downwind landing in a Taylorcraft. I advised him that it was not only my first but it was also going to be my last. As it turned out, he was a retired flt instructor and had learned to fly in 41 in, of all things, a Tcraft. We spent the next 2 hours talking Taylorcrafts and flying and this Fri, I'm going back to Enid and he and I are going flying.

So, here is a situation that could have been a disaster that turned out well.
But, Hell will freez over before I ever make another down wind landing!!!!!

[lktiller]

Re: wind variable

I'd like to hear more about the 'rudder reversal'? You mentioned this happened just after touchdown? Was this a Wheel landing? Before the tail wheel made contact with the ground?
Not nit-picking, I'm after education through someone else's experience.
We're glad the plane (and you) are ok. Thanks for sharing.

Been there, done that! 'cept 33943 was landing 22 with winds 140 @ 22G30!!

I regularly make downwind landings at my field. Wind up to 10kts. Full stall, three point. Sometimes the tailwheel touches first. Don't have enough room for a ground loop!!!!!
theory is: keep the rudder moving faster than the wind until the actual touchdown when the tailwheel cane take over.

Larry Tillery

[Mark Julicher]

Re: wind variable

Paul,

I got my CFI at Woodring Airport in 1977 and your anecdote brought back a few windy memories.
Thanks.
Best Regards,
Mark Julicher

[paulp]

Re: wind variable

Larry,

This was a 3 point and appearantly, I caught a gust just before td. I don't know about you, but I can't imagine making a downwind landing in an acft as light as a Tcraft. I know that a 120/140 probably would not have reacted the same and in a 172 it would not have been noticed.

All I know is that it will have to be one nucler powered, armaggadan type of emergency before I will try another one. That being said, I'm glad for the experience.

The reason for the reversal is that when the wind speed exceeds the forward speed of the acft the wind exerts force on the oppsite side of the rudder that exceeds the amount force being exerted on the upwind side by the forward movement of the acft. If the acft is not on the ground, you get to do what I now call the Taylorcraft Two-Step.

Hey Mark,
If you get to OK, give me a call. I'm located @ GOK

[selje]

Re: wind variable

Over half of the landing here at my 1700 ft. uphill 50 wide grass strip (29NC) are downwind and have never noticed a rudder reversal. If winds are over 15 knots, I will make a downhill landing over the large shop on the uphill end of the runway.

[NC36454]

Re: wind variable

OK...I can't stop myself. This rudder reversal thing is driving me crazy. I was taught to fly by an old instructor and I am grateful for him everyday. He constantly drilled into my head something that has always kept me in check. He would say over and over that airspeed was airspeed was airspeed. Regardless of outside windspeed. airspeed was airspeed. Ground speed will be affected and wind will cause you to drift, but airspeed remains.

This rudder reversal issue attempts to make me feel that airflow (from the rear) across the rudder has exceeded airflow along the normal flight path. This happens in a tailslide but only after the airplane has been placed in a stall configuration.

I got into a discussion with an "ultralight instructor" a few years ago. He tried to convince me that if I was happily flying along at 40 and I encountered a 40 mph tailwind, the airplane would stall. I re-evaluated his skills and changed instructors.

I mean no ill with this post, I just believe that we (Taylorcraft community) need to promote discussions such as this. Open dialogue is the process that allows for continuing improvement.

Thanks,
Ken

[Richard Boyer]

Re: wind variable

First, This is a GREAT subject!!!!

There is a difference between Airspeed and GroundSpeed.

I think the tail wind thing is a bit deceiving. I would think that while you are flying that tailwind at 40mph is awesome! Provided you don't have to turn around... What if you stalled the plane? Your stall speed is going to be the same, but your ground speed will be stall + 40! So my ground speed in this instance would be 88mph! In the air, who cares? But on the ground, this is a completely different animal.

When taxi-ing and you have a quartering tail wind you use down aileron on the side the wind is coming from and down elevator. According to my flight training handbook this "keeps the wind from getting under and lifting the wing and tail". This is an unatural feeling! If you are trying to stop and you are going 20mph forward, but have a 40mph tailwind what are your control inputs supposed to be? I would say backwards.

So, does it stand to reason that with a 40mph tailwind and a ground speed AND airspeed of 20mph that your controls are going to be fairly ineffective? I would say yes and at this point you are using the deflective properties of a tailwind to stay in control. (landing downwind never seems like a good idea).

looking forward to learning some stuff on this one!!

Richard Boyer
N95791
Georgetown, TX

[lktiller]

Re: wind variable

good points.
both instructors remarks are correct. the 'old' one is teaching from practical experience, the 'new' one's example is true but not realistic.

That is unless you're in a thunderstorm or behind a 'heavy'. Then one will be more concerned with flying than rudder reversal.

The other point is: to feel rudder reversal the wheels need to be touching the ground so the plane has something to pivot around. ie: ground loop caused by a tail wind. (at least that was my excuse. )
In the air you'll just get a jolt!
Picture the aircraft flying in a moving block of air. The jolts come from the transition from one air block moving in one direction to another block moving in another direction. Example: flying through a thermal.
Rarely would the wind direction CHANGE be enough to reach indicated stall speed. More likely to cause everything in the baggage compartment to swap places !!!!!!!! (reminder: wear seat belt)

Yes, fly the indicated airspeed, fly indicated the airspeed, fly airspeed the incidated.

[NC36454]

Re: wind variable

lktiller,

Well put! You mentioned something that almost everyone overlooks, these outside wind factors come into play when the airplane is in solid contact (like earth). The one that REALLY gets me going is the "weathervane". There are folks that actually believe airplanes will "weathervane" while in flight! There's a reason that we account for wind correction angles to stay on course. I would have given anything about 20 years ago to have one of these "weathervaning" airplanes when I allowed myself to get blown 150 mile south of course. Finally figured out that I was seeing the Rio Grande....only on the wrong side of the airplane!

Good discussion here guys!!

Ken

[Jim Hartley]

Re: wind variable

My take on this issue...When landing either downwind or upwind your speed over the ground is the sum of your speed in the mass of air and the speed of that mass of air over the ground. Another mass of air(a gust) that is moving faster than the mass that you are currently flying in,will either increase your control effectiveness(upwind,providing no wind shear) or decrease your control effectiveness(downwind,providing no wind shear). We have all seen this effect when flying in gusty winds and making upwind and downwind turns. Downwind turns need to be done with caution because a gust will raise your wing higher quickly and put you closer to a stall. In upwind turns a gust will reduce the bank. Variable winds and
Wind shear is a dreaded phenomenon that can ruin your day even if you do everything right...except maybe the decision to fly in conditions that may be conducive to shear. Then again...wind gusts are in fact wind shear!!! Hmmmm?

Aw, hell!!!... I just stay away from downwind landings because I am already at at disadvantage. No sense in borrowing trouble! I do some times.

[Jim Hartley]

Re: wind variable

Ron,did you coin the term;"'busier than a one legged man in an ass kickin' contest"?

Jim

[lktiller]

Re: wind variable

I done 'fessed up but the experience is worth repeating.
direct downwind landing, wind 22G30, Wheel landing ok, put the tail down with elevator, Wind gust said NO and over we went.
Sure, I shoulda rode it to a stop with the elevator in the down position but I was more concerned with clearing the runway.
Yes, that is a downwind landing with wind gusting 22kts to 30kts. T-Storm over the west end of the runway pulling the air from the east. I'm SVFR with the tower watching.
Maybe this should be in the 'never again' category.
Here's the mistakes, for those watching.
1) More concerned with following procedures than flying the aircraft.
2) Should have turned around and landed at my alternate choice. I actually told the tower I was turning around but they cleared me for landing so rather that overrule them I went ahead and tried it.
My instructor used to call it 'ground-itis'. Wanting to get on the ground as soon as possible.
3) Yes, hold the tail off the ground in a wheel landing, that goes double for a tailwind.
4) Make certain the Airworthiness Certificate is valid. That's the only thing the investigators found wrong!!!!!!! It was a copy. Since been replaced.