Tailwheel takeoff - best side for crosswind?
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The theory is very well explained in The Complete Taildragger Pilot
What I learned the other day is that one side is better than the other for crosswind takeoffs. Luckily there were no spectators
What I learned the other day is that one side is better than the other for crosswind takeoffs. Luckily there were no spectators
Last edited by rusty sparrow; 7th Sep 2011 at 05:19. Reason: fixed link (again)
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I know we answered the original question a while back, but continuing the drift a little, the place I did my tailwheel had a training aid - a smallish 'bmx' wheel mounted on a handle (one of those big 'pegs' the youf of my time had to stand on and do tricks).
You held the handle, the instructor spun it up, make the pitch change via the handle. I thought it was very effective both in cementing the idea of procession, and the suprising magnitude of force from even a small, light wheel at low speed. What a big prop tries do do to the crankshaft in tumbling flight must be pretty impressive..
You held the handle, the instructor spun it up, make the pitch change via the handle. I thought it was very effective both in cementing the idea of procession, and the suprising magnitude of force from even a small, light wheel at low speed. What a big prop tries do do to the crankshaft in tumbling flight must be pretty impressive..
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I certainly agree that pilots must be prepared for taildraggers to swing, and that understanding, and anticipating the factors which could affect this is a good thing.
However, once we've considered the torque, P factor, Coriolis affect, tides, and colour of the rudder, I think it is even more important to remind ourselves that the key is to simply be prepared for a swing at all. Sometimes you can analyze things in excess. Then you form an opinion as to what to prepare for, and forget to prepare for the other possible event too. Then "the other thing" happens, and surprises you even more.
Whenever I fly the taildragger, I figure that it is it's only mission in life to have me going off the runway sideways. So I'm going to watch for every clue, and fight back by simply keeping it straight and centered on the runway. Yup, I've scared myself a few times (particularly in the jump 185, which I later found to have no steering whatsoever). All you can do is stay sharp, and expect the worst. If the plane you're flying has an advantage with the wind from one side, or the other, that's good to know, play to that, but never take your eyes off it on the runway!
However, once we've considered the torque, P factor, Coriolis affect, tides, and colour of the rudder, I think it is even more important to remind ourselves that the key is to simply be prepared for a swing at all. Sometimes you can analyze things in excess. Then you form an opinion as to what to prepare for, and forget to prepare for the other possible event too. Then "the other thing" happens, and surprises you even more.
Whenever I fly the taildragger, I figure that it is it's only mission in life to have me going off the runway sideways. So I'm going to watch for every clue, and fight back by simply keeping it straight and centered on the runway. Yup, I've scared myself a few times (particularly in the jump 185, which I later found to have no steering whatsoever). All you can do is stay sharp, and expect the worst. If the plane you're flying has an advantage with the wind from one side, or the other, that's good to know, play to that, but never take your eyes off it on the runway!
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rusty sparrow, there is another performance factor you may wish to consider - and I am rather surprised that nobody has mentioned it so far.
Meteorologically speaking, in the Northern Hemisphere, the wind will tend to veer and increase on the climb-out. Therefore, taking-off with the crosswind from the left will result in an increasing headwind in the climb, thus improving the climb angle. Conversely, a crosswind from the right will mean climbing into an increasing tailwind which will produce a reduced climb angle.
This is certainly worth considering, especially if obstacle clearance is a problem on departure.
JD
Meteorologically speaking, in the Northern Hemisphere, the wind will tend to veer and increase on the climb-out. Therefore, taking-off with the crosswind from the left will result in an increasing headwind in the climb, thus improving the climb angle. Conversely, a crosswind from the right will mean climbing into an increasing tailwind which will produce a reduced climb angle.
This is certainly worth considering, especially if obstacle clearance is a problem on departure.
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Personally l use the rudder to keep straight and the ailerons to balance on the into wind wheel and let it fly when it`s ready, or land ...... the process is the same. Of course in the first instance the throttle is open, and in the second closed.
But that`s just me.
But that`s just me.
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lt`s not in a slip, balanced on one wheel is the way to go, l did assume that the tail had been raised. l see the confusion !
My experience has been that the lower the power the greater the need for "talkies" with the aircraft in a cross wind.
My experience has been that the lower the power the greater the need for "talkies" with the aircraft in a cross wind.
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D-120
I flew a D-120 for quite some time.
During X-Wind take off, it was best to keep the tailwheel on the ground at the start of the take off run, as with most taildraggers.
Wind from the right is the worst. You automatically give right rudder for torque and by doing so, you put the rudder surface square to the right hand X-Wind. that + the big flat fuselage surface can give a nasty surprice if not prepared.
So ; keep the tailwheel on the ground, you need the wheel friction to keep things in balance. You can easily take off in 3 point, but mostly I pushed the nose over as soon as I felt solid rudder control.
Tip: grease the vertical axis well to take load of the springs to the rudder. it does not seem like a lot, but it makes a HUGE difference.
I never had a "worry" moment, but the man who bought it from me, had her on her nose 2 weeks later. +> NEVER BRAKE WITH BOTH BRAKES AT THE SAME TIME;
During X-Wind take off, it was best to keep the tailwheel on the ground at the start of the take off run, as with most taildraggers.
Wind from the right is the worst. You automatically give right rudder for torque and by doing so, you put the rudder surface square to the right hand X-Wind. that + the big flat fuselage surface can give a nasty surprice if not prepared.
So ; keep the tailwheel on the ground, you need the wheel friction to keep things in balance. You can easily take off in 3 point, but mostly I pushed the nose over as soon as I felt solid rudder control.
Tip: grease the vertical axis well to take load of the springs to the rudder. it does not seem like a lot, but it makes a HUGE difference.
I never had a "worry" moment, but the man who bought it from me, had her on her nose 2 weeks later. +> NEVER BRAKE WITH BOTH BRAKES AT THE SAME TIME;
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I find keeping the nose straight with the rudder and the wings balanced with the ailerons easy enough in a x wind landing (was a glider pilot years back). But the problem I had was the takeoff with wind from the left - while slowly accelerating I just gracefully weathercocked as I ran out of rudder. That's because I would have pushed forward to get the tail up and weathercocked on the main wheels - I should have kept the stick back until I got rudder control 
Don't know how much torque is an issue? The Jodel D120 uses the C90 engine - wikipedia comments "While slightly less horsepower than the O200, many floatplane operators prefer the performance of the C90 over the O200, due to its higher torque at lower rpm. This is primarily due to the C90's camshaft design. The C90 is alo known by its military designation of O-205"
Don't know how much torque is an issue? The Jodel D120 uses the C90 engine - wikipedia comments "While slightly less horsepower than the O200, many floatplane operators prefer the performance of the C90 over the O200, due to its higher torque at lower rpm. This is primarily due to the C90's camshaft design. The C90 is alo known by its military designation of O-205"
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Vilters - re "Tip: grease the vertical axis well to take load of the springs to the rudder. it does not seem like a lot, but it makes a HUGE difference."
Sounds a useful tip - could you let have a little more detail i.e what/where you mean by the vertical axis?
Sounds a useful tip - could you let have a little more detail i.e what/where you mean by the vertical axis?
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I think Vilters is referring to the tail wheel pivot. If not free to rotate easily it will add to rudder loads as you stretch the springs, and also you will not get sufficient 'steering' from the tailwheel.
Having said that, I much prefer the free-castoring tailwheel of the Chipmunk. Its unrestrained tailwheel allows the aeroplane to rotate almost in its own length; 360 degrees rotating around either mainwheel. In fact, it's great fun to do alternate 360s like that on the apron (not near parked aircraft though just in case the brake fails!).
It also makes it far easier to manhandle the aeroplane on the ground, in and out of the hangar for instance.
Having said that, I much prefer the free-castoring tailwheel of the Chipmunk. Its unrestrained tailwheel allows the aeroplane to rotate almost in its own length; 360 degrees rotating around either mainwheel. In fact, it's great fun to do alternate 360s like that on the apron (not near parked aircraft though just in case the brake fails!).
It also makes it far easier to manhandle the aeroplane on the ground, in and out of the hangar for instance.
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X-Wind in a D-120 ( ex OO-FDP ) now G-BYBE I believe
Correct, but the Chipmunk does not have a FLAT fuselage. It is round, and has less problems with X-Wind.
A free castering tailwheel can not help you maintain direction as well as a steerable tailwheel.
1. Torque, indeed th C-90 has quite some torque and the engine in a D-120 has no offset to correct it.
2. The moment you lift the tail. That very moment the aircraft WILL veer to the left. (Gyroscopic precision), so actually you need MORE right rudder input, the moment you push the nose over.
3. Best practise when in doubt? Keep the tailwheel on the ground untill positive rudder control can be achieved, and be prepared to give more right rudder the moment you lift the tailwheel OFF the ground.
4. And indeed, use ailerons.
Yes, i was talking about the vertical ax at the tailwheel pivot point.
A free castering tailwheel can not help you maintain direction as well as a steerable tailwheel.
1. Torque, indeed th C-90 has quite some torque and the engine in a D-120 has no offset to correct it.
2. The moment you lift the tail. That very moment the aircraft WILL veer to the left. (Gyroscopic precision), so actually you need MORE right rudder input, the moment you push the nose over.
3. Best practise when in doubt? Keep the tailwheel on the ground untill positive rudder control can be achieved, and be prepared to give more right rudder the moment you lift the tailwheel OFF the ground.
4. And indeed, use ailerons.
Yes, i was talking about the vertical ax at the tailwheel pivot point.
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In my experience it is the pilots that have preconceived ideas that have the most trouble.
It's a little bit like "going with the force ", it sort of becomes natural.
It does take time but make haste slowly and it will come.Its almost as bad being in front of the plane and overcontrolling than being behind and playing catch up.
Try to use smooth inputs rather than small jerky ones, keep your eyes focussed well ahead so as to pick up movement quicker and have more time to react.
In time you'll wonder what all the fuss was about.
It's a little bit like "going with the force ", it sort of becomes natural.
It does take time but make haste slowly and it will come.Its almost as bad being in front of the plane and overcontrolling than being behind and playing catch up.
Try to use smooth inputs rather than small jerky ones, keep your eyes focussed well ahead so as to pick up movement quicker and have more time to react.
In time you'll wonder what all the fuss was about.
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[QUOTE] Personally l use the rudder to keep straight and the ailerons to balance on the into wind wheel and let it fly when it`s ready, or land ...... the process is the same. Of course in the first instance the throttle is open, and in the second closed.
But that`s just me.
[QUOTE]
Well for me, the above says it all really
But that`s just me.
[QUOTE]Well for me, the above says it all really
