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Take off procedure?

miyu1975

miyu1975

Well Known Member
I am curious other opinions and mechanics of take off. I feel like I still need to tweak mine a bit... Here is mine... I have manual trim with no indicator as to where it is set..so I crank the manual trim all the way to the right, then turn back three half turns left....this has been my take off setting, which is still trim for nose down. I slowly add full power with the stick forward so the tail comes off runway quickly. Once the tail is off the pavement I build up speed til about 70 knots...this still requires holding stick forward with slight pressure so that I don't start flying before she is ready. Once off the ground and climbing I adjust the trim a little for nose up, otherwise I am holding back pressure on the stick to climb out.

I feel like I have to much nose down trim for take off...at 70 kits on the ground I have pull back to get off the pavement. But I don't want to set the trim to much nose up...as that has really bad effects too..I am trying to find that sweet spot I guess..

At take off is your trim flush with the elevator..naural? mine is not with my current procedures.

Do you build speed and get the tail up first or just fly it off runway from a three point stance..
 
Mike Seager taught me that it's ready to fly when the tailwheel comes up. It's worked for me b/c the plane accelerates so fast once off the ground.
(Not coincidentally, I'm sure, that's the same speed at which I feel the mains start to "dance." Many years ago I was taught to look for that cue to determine when to rotate the C-182.)

He also had me do one three point takeoff on the last day of transition training (with partial flaps). That works great too except you have less visibility and, perhaps, not as much control in winds.

Haven't messed with the trim before takeoff. It's generally at neutral and then I just trim out once I get my climb speed nailed. Eventually, I'll figure out how many turns from neutral it is for climb speed and preset that before takeoff. Everything up to that point, then, will be flown with as much pressure on the stick as needed.

One added item, Ryan, FWIW--Mike had me just let the elevator float and let the tail come up on its own. Doing that may mean that my tailwheel comes off the ground a bit later (and perhaps with higher airspeed) than you if you're applying forward pressure on the stick.
 
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Ryan,
Congratulations on the completion. I spend some time checking your build and your log is a good one.
I have only been flying a Citabria tailwheel but have ridden in RV-7's.
In the Citabria the tail Wheel comes up immediately with the stick pushed forward like you talk about. In the RV tailwheel I have been in, the tailwheel has such good control that it stays on the ground much longer. I prefer a neutral trim. Tailwheel down until lift off would be a soft field procedure but still not completely down. You don't want it dragging.
 
I set the trim level with the elevator and use 13° flap. (15° would be optimal, but 13° is where my 1st notch is)
I raise the tail slightly and steer.
The airplane flies off at about 60-65 mph.
 
miyu1975 said:
I am curious other opinions and mechanics of take off. I feel like I still need to tweak mine a bit... Here is mine... I have manual trim with no indicator as to where it is set..so I crank the manual trim all the way to the right, then turn back three half turns left....this has been my take off setting, which is still trim for nose down. I slowly add full power with the stick forward so the tail comes off runway quickly. Once the tail is off the pavement I build up speed til about 70 knots...this still requires holding stick forward with slight pressure so that I don't start flying before she is ready. Once off the ground and climbing I adjust the trim a little for nose up, otherwise I am holding back pressure on the stick to climb out.

I feel like I have to much nose down trim for take off...at 70 kits on the ground I have pull back to get off the pavement. But I don't want to set the trim to much nose up...as that has really bad effects too..I am trying to find that sweet spot I guess..

At take off is your trim flush with the elevator..naural? mine is not with my current procedures.

Do you build speed and get the tail up first or just fly it off runway from a three point stance..
Click to expand...

By the time you hit 70 kts you should be well established in the climb. The plane can be ready to fly much slower than 70, most likely around 55-60 kts. Any faster on the ground is just wear and tear on the tires and gear.

Set the trim to neutral (or whatever you need to have neutral control pressure as you rotate) and retrim as necessary once settled into an accelerating climb.
 
Right Sam.. I thought 70 was a little hot to be rolling too, which is no doubt do my nose down trim. I will make some adjustments tomorrow and put the trim neutral and see how that feels.
 
miyu1975 said:
I slowly add full power with the stick forward so the tail comes off runway quickly.
Click to expand...

Why force the tail up ASAP? Nothing wrong with doing that in calm conditions, but in strong gusty/x-wind conditions, you could find yourself making a sharp turn toward the weeds doing that...especially with a left x-wind. I can't think of any advantage to forcing the tail up ASAP. I fly the RV the same as any other tailwheel airplane - I let speed build a little and then "nudge" the tail up...but not very high - which brings me to my next point...

miyu1975 said:
Once the tail is off the pavement I build up speed til about 70 knots...this still requires holding stick forward with slight pressure so that I don't start flying before she is ready.
Click to expand...

Seems you are holding it on the ground needlessly long. I usually raise the tail less than a foot and hold that attitude and let it fly off when it's ready...no "rotation". This works well regardless of density altitude and the load you're carrying - the airplane will fly when it's ready. I can't remember the last time I looked at the ASI during takeoff in a tailwheel airplane - I never do it. I don't glance at it until I'm off and climbing out. To me, I guess a lot of it is just that it seems like a more "artful" way to fly than forcing it to stay on the ground until a certain number shows up on the ASI and then pulling it off.

Most of these issues are a matter of personal preference and technique. There is no right or wrong. Just keep in mind that you're giving up a bit of directional control authority early in the takeoff run if you push the stick full forward as you start to roll. This could only really be a problem in strong x-wind/gusty conditions. Same concept applies when lowering the tail during the rollout from a wheel landing. You see lots of folks push the stick all the way forward, keeping the tail up as long as possible. Again, you're setting yourself up for a potential trip into the ditch doing this in certain wind conditions. There's just no reason for it.
 
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Got it Luddite and I agree I have been raising the tail to quickly and holding the plane on the ground way longer than needed. It didn't feel right to me...thanks for the advice.
 
In my RV-6 (has a pretty steep-pitched for cruise wood prop) if I raise the tail early and rotate from level pitch, the airplane want to dart to the left pretty abruptly as soon as the mains leave the ground. But, if I just hold the stick neutral and left it fly off when it's ready, in a mostly three-point stance, it's much easier to keep it straight, tracking the runway centerline when it lifts off on its own.
 
I too have manual trim with no indication.

I trim during the landing sequence. Since I land and lift off at close to the same speed, I seldom touch the trim until after after lift off when I add a little nose-down to set the faster climb speed relative to the landing/take-off speed.

For take-off I quickly and smoothly add throttle with just a tiny bit of forward stick. The small amount of forward stick gives me a feel for when the tail wants to fly. I then hold the stick and let the whole plane tell me when it's ready to fly.

I use the above technique because I fly mostly off of short grass runways.
 
Manual trim marking

I marked the manual trim location for take off with a magic marker and then by VERY LIGHTLY filing a notch all the way around the shaft of the manual trim control. I then used some red fluorescent fingernail polish to make the mark easily visible. When I set take-off trim now I just rotate the control until the red mark barely disappears. It has worked well for 100 hrs now.

As far as take off attitude and technique, it has been covered well already.
 
How about short soft fields?

On short soft feild takeoffs, do you do anything different than what was discussed. Mel mentioned 13 degrees of flaps. Does it help or hurt to get the tailwheel up sooner, or just let it come up as was mentioned. Does more flaps help (shorten) take off distance?
 
Neal@F14 said:
In my RV-6 (has a pretty steep-pitched for cruise wood prop) if I raise the tail early and rotate from level pitch, the airplane want to dart to the left pretty abruptly as soon as the mains leave the ground. But, if I just hold the stick neutral and left it fly off when it's ready, in a mostly three-point stance, it's much easier to keep it straight, tracking the runway centerline when it lifts off on its own.
Click to expand...

I'm a little perplexed here, can you not maintain the centreline with the rudder? :confused:
 
Geeman said:
On short soft feild takeoffs, do you do anything different than what was discussed. Mel mentioned 13 degrees of flaps. Does it help or hurt to get the tailwheel up sooner, or just let it come up as was mentioned. Does more flaps help (shorten) take off distance?
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You RV ailerons have 15? of "down" movement. That is pretty much optimal for maximum lift at minimum drag. Flaps work the same. If you have electric flaps, push the stick to one side and align the flaps with the lowered aileron. This will give you optimum take-off flaps.
I've tested this on quite a few RV models and 15? yields the shortest take-off roll.
I use 13? because the notches on my manual flaps are 13?, 26?, and 39?.
 
I have manual trim, too (although with a nosewheel). It's usually pretty full out after a previous landing, so I just give it four or five turns and that usually brings the knob back to the width between the tip of my finger and the knuckle. That usually works fine for takeoff.

Re: position indicators. Bah. I see lots of flap indicator contraptions to. I don't bother. I give it a shot of flaps for a few seconds on downwind, another shot on base. The plane -- as it does with the trim -- tells me where everything is positioned. I only listen to her. :)

On takeoff, I use a LOT of right rudder. A LOT of right rudder.
 
madhun said:
I'm a little perplexed here, can you not maintain the centreline with the rudder? :confused:
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The amount of right rudder needed to track straight while the mains are still rolling on the ground versus the amount of right rudder needed to keep the airplane tracking (crabbing) straight down centerline once the wheels leave the pavement is greatly different. It takes an extra strong push of the right rudder once the wheels leave the ground if I take off in level attitude with the tail up. If I put that much right rudder in with the wheels still on the ground and the wings unloaded, I'd run off the right side of the runway.

And again... if I take off in 3-point attitude, this phenomenon is way less pronounced. It only does it strongly if I raise the tail early as possible, accelerate to flying speed on the mains in level attitude, then rotate the nose up to try to "muscle" it into the air.

A friend of mine's RV-4 with a similar Aymar-Demuth prop (but less pitch) does this a little too, but not nearly as pronounced as mine.
I attribute this phenomenon to the extreme cruise pitch of this wood prop just having an abnormally large amount of P-factor.
 
I'll just echo others who say that 70kias is WAY too fast to be on the ground still. Mine is ready to fly at 55 Mph but I hold it down till 60 (my ASI reads a little low, so maybe it's 65 mph). A little flap, as pierre says, doesn't really help get the tail up faster (to me, at least), it just seems to get it "ready to fly" a little sooner and more willing to start climbing at Vr.

As far as trim, I look back to verify that the trim tab is even with the TE of the elev (I can just BARELY see it if I turn around).

After rotating, a turn or two of trim to get it settled at climb speed, but I like the trim neutral at liftoff so I can feel what the plane wants, not what the trim wants.
 
Great discussion...so I flew today and did several take offs and landings. This time instead of my three turn to the left I turned five times which happens to nearly flush with the elevator. On takeoff I slowly and smoothly add power, maintain the centerline with rudder. I added slight forward pressure on the stick and felt the tail raise slightly, by then I had 60 kts and was off the ground.. Much smoother than my prior takeoffs.
 
miyu1975 said:
Great discussion...so I flew today and did several take offs and landings. This time instead of my three turn to the left I turned five times which happens to nearly flush with the elevator. On takeoff I slowly and smoothly add power, maintain the centerline with rudder. I added slight forward pressure on the stick and felt the tail raise slightly, by then I had 60 kts and was off the ground.. Much smoother than my prior takeoffs.
Click to expand...

Then that's the way to do it! ;) And I'll bet it's predictably repeatable too.
 
SOL has an engraved marking on the trim control's shaft. It's cut with a fine blade on a lathe, about as deep as the thread on a smallish bolt. It lines up flush with the top of the bezel when the trim tab is neutral.

No need to count turns or even look at it; just run your fingernail along the shaft until you find the mark, then wind it in until it disappears, then commence take off.

- mark
 
Glad you found things improved.

I am sure Pierre will concur, although he probably has more experience here than most, and have the least :D

The less you do the better. concentrate on feet, the less you do the better the plane flies.

Same when I fly a Tiger moth, keep it steady, and she flies.....

Now I am not that skilled, so perhaps do not over fly the plane!

Been a great thread to read and learn from to! :)
 
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