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Thread: Can the tail get too high?

  1. #1

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    Can the tail get too high?

    I am new to tail-wheel airplanes. I built and am flying an SQ2. Lots of fun. Takeoff is very quick as the plane has too much power and will fly at a ridiculously slow speed.
    Several people have told me that I should practice rolling the plane down the full length of the runway on the mains to gain more practice for wheel landings. But I end up lifting off after only a hundred feet or so because I am hesitant to push the nose down enough to hold the mains on the runway. It feels like I'm going to push the prop into the pavement. Some people have told me this is not possible and some (who haven't tried) say it is. My question is this: in a Super Cub can I push the stick all the way forward while applying enough power to go down the runway at say 40 mph and still have prop clearance?
    Years ago I asked a friend who had a Pacer, and he demonstrated it to me (full power, stick all the way forward, 10,000' of runway). Felt like the tail was 10' in the air but nothing touched.

  2. #2
    Eddie Foy's Avatar
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    I had to overcome the same thing when I bought my Cub. Pushing forward just felt wrong. Practice it alot on a grass runway. Get the tail up and reduce power a bit.

    I wont say you cant hit the prop on takeoff but it would be damn difficult.
    "Put out my hand and touched the face of God!"

  3. #3
    cubdriver2's Avatar
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    Put your prop vertical and lift the tail with your hand and see what you have for clearance.

    Glenn
    "Optimism is going after Moby Dick in a rowboat and taking the tartar sauce with you!"
    Likes alaskaflyer180 liked this post

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    You should have no problem

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    "Takeoff is very quick as the plane has too much power and will fly at a ridiculously slow speed."

    You can never have too much power. As the old saying goes "Too much power seems just about right!"

    Gary

  6. #6

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    I was told the same thing when water skipping that you can push the stick forward and all the way forward, Believe me you can touch the prop and it will get your attention and if you're not quick on the stick the next step will be on your back . practice without full power use just enough to keep the tail up.

  7. #7

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    In Cub or Skywagon it has been impossible for me to lift the tail "too high" because the plane will fly no matter how hard I push forward with mains on the ground. That's how most of us will control the plane while taking off in unfavorable winds, by keeping the plane pinned to the ground until maximum speed is achieved. When I can't hold it on any longer I transition to a climb as required by terrain or obstacles. If you choose to push it into the ground after wheels are up you're on your own.

  8. #8
    SteveE's Avatar
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    Hmmm, so some are saying you can push the stick all the way forward, and some say no. I'll pin it with a little forward stick, but until I'm proven wrong, ain't no way I'd go full forward stick. All you are doing, if nothing bad happens, is driving it into the runway putting excessive wear and tear on the tires.


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  9. #9

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    How much forward pressure is required to keep the mains on is determined by speed. As hard as you push the tail will only go so high (assuming you're accelerating, NOT decelerating). As speed builds the pressure to keep it high increases as you accelerate past your normal takeoff speed. You can only negate AOA for so long before the plane flies off in a level attitude. Max pressure will get max speed before it flies off in spite of the forward pressure. If the winds are crossing and gusting and there are big trees or rocks close on the downwind side? Faster is better to maximize control. Many of us occasionally wish we could get more speed before the wheels lift and we're at the mercy of the wind. Wear on the airplane is not the primary concern.

    What mr kandle is describing is one of my primary concerns as I build my own SQ. I can get my Cessna in and out in winds that park many Cubs. I expect my unfavorable wind threshold will need to be adjusted for the slow-flying SQ.

  10. #10

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    Taking off SQ2

    Agree with Steve. Under normal conditions, trimmed properly, Cub or Skywagon: wear and tear increases and acceleration diminishes by pushing stick forward. Fly away as we alight, tailwheel near the ground. Almost three-point up and down. Challenging conditions, whole other thing.

  11. #11

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    Quote Originally Posted by stewartb View Post
    In Cub or Skywagon it has been impossible for me to lift the tail "too high" because the plane will fly no matter how hard I push forward with mains on the ground. That's how most of us will control the plane while taking off in unfavorable winds, by keeping the plane pinned to the ground until maximum speed is achieved. When I can't hold it on any longer I transition to a climb as required by terrain or obstacles. If you choose to push it into the ground after wheels are up you're on your own.
    Stewart your point is spot on and works amazingly well especially with strong cross wind take-offs... but man does it take some push with a big engine 180, I usually add some forward trim to help keep when I know I need to do it that way. That extra speed sure makes it easier to stay straight after lift-off.
    Last edited by OLDCROWE; 04-22-2016 at 09:26 AM.
    Remember, These are the Good old Days!

  12. #12

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    First place the prop horizontal than raise the tail on a bench or oil drum until the plane is level, than sit in the plane to get a proper sight picture. Be careful because as you lift the plane the tail will become lighter. Once you know what you are looking for it will be easier to keep the tail up. The other thing is to have someone video you when you are trying to do tail high taxi, what you FEEL in the aircraft may not be what you get. I am currently trying to keep my tail higher for improved braking and the video helps. If you want to do tail high taxi entire runway length than pull the power back to around 1750 RPM (depending on engine/prop and you should stay on the ground). There is a video of a guy that got his prop on takeoff during the Valdez comp a few years back but it looks like he did not release brakes soon enough. Do not do full nose down trim to lift the tail while you do this. Make you arm do some work so you can respond quicker. I agree with the others if you fly enough in strong winds one day you will need to stick it and that is hard to do with the tail down. Once you get that all down than you can go to one wheel and start over. Might not hurt to get an CFI that knows how to do this stuff for pointers.
    DENNY

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    I think my son can answer this question especially if you're on waterClick image for larger version. 

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  14. #14
    hotrod180's Avatar
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    I get nervous when I see airplanes with the tail extremely high. I know a couple guys that vigorously push the tail up after wheel anding, one of them managed to nose his airplane over landing on a snowy strip. Didn't see it happen so don't know if that tail-high habit contributed but probably so I think.

    Another guy I know was pushing his brother to fly his homebuilt. Told him push the stick forward hard to get the tail up. Bro pulled onto the runway, cobbed the throttle, and shoved the stick all the way forward as directed-- and the airplane went up on it's nose just as quick as a wink! Didn't need very much forward stick if any as the tail was extremely light, so poor advice, but I think the bro ended up paying for the replacement prop. The only good thing about this mishap was that I sold him a used prop I had, and got asking price to boot.
    Cessna Skywagon-- accept no substitute!

  15. #15
    skagwaypilot's Avatar
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    Hold my beer and watch this takeoff

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    L18C-95's Avatar
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    You don't need extra speed on a wheel landing, so trying to pin it at too fast a landing speed might bring on a case of the crow hops. I actually prefer a tail low wheel landing and then you move the stick gently forward to the stop as you decelerate, and then bringing the stick back as the tail starts to settle.

    I expect wheel landings that are fast and followed by full forward stick and heavy braking might not be great for the gear legs and bungees, and could result in a prop strike.

  17. #17

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    It appears that all of the cases given here where the plane went on its nose (or the prop hit) there was some force being applied at the wheels (brakes, snow, water). As the tail rises up with the mains on the ground the angle of attack of the tail becomes less and less (can't do an outside loop with the mains on the runway). Eventually the AOA of the tail will be such that it reaches an equilibrium (any higher tail attitude and insufficient upward force is generated to hold the tail and any lower tail height and it will have enough lift to move it back up). The question here is where is the prop to ground clearance when that equilibrium point is reached. I've got the trim set at about 45 mph for takeoff so it takes a lot of forward force to keep the tail up (especially with significant power). I've got about 5,000 hours of nose wheel time and only 30 or so of tailwheel time. So it is kind of scary to think that there is nothing but air and my careful control of the elevator between my prop and the asphalt.
    Thanks Tailwindflyer thanked for this post

  18. #18
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    That was pretty much my comment. You would have a tough time putting a plane on its nose that did not have any brakes (assuming wheels) no matter how hard you push forward. I go stick full forward until you get the level picture, then ease back as the tail comes up - or keep pushing forward in the case of a landing rather than takeoff, but I fly the tail down rather than stall it like the FAA curriculum advises.

    Conditions are important, if you are any sort of big crosswind you are going to want the positive control of having it firmly planted in my opinion, on a calm day on nice grass or asphalt, pull on all the flaps and take off in a 3-point. It will be the shortest takeoff (technique wise) most people will ever make.

    sj
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  19. #19

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    I don't know what's too high but on landing at Halifax International with 185 brakes frozen solid it felt like I was looking nearly straight down at the runway before the brakes broke clear within a few seconds of each other. As she started to tip over, I said to myself here goes the prop. Bang, bang, down came the tail. I doubt stick forward will cause hit on the prop.

  20. #20

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    I think there's old school and new school here. I also have to apply a geographical differences filter here too.

    The guys that taught me to fly - and I mean the ones that TAUGHT me to fly not the pups I did dual with, but the guys with experience - they're either too old to fly now or have died - would view raising the tail in the manner described here would be a definite no-no. Those guys learned to fly in Tiger Moths where the three-pointer was the norm and you were expected to three-point in all but the meanest conditions.


    The guys I have to do BFR's with now are a generation or so younger and seem to have a completely different view towards wheelers and they are done at what seems to me to be incredible speeds with the tail up in the clouds. I can see some of this view point coming through in the answers here.


    I just apply my engineers mind to the problem. As the C of G rotates around the axle it gets higher and further forward. This change in position makes the plane more likely to go on its nose so is best approached with caution. In a Super Cub trimmed for level flight the "right" time to rotate is just as you're having to hold back pressure to maintain the "tail up" attitude. Sure as god I wouldn't want to be shoving it further forward at that point!


    As I try to recall instances of taildraggers having nosed over on their back I can think of just one. No brakes, snow, mud or anything else was involved to drag the wheels back. It went over all on it's own just with elevator. And I can think of a few where the plane has gone up on its nose, so sure, you can do some damage by shoving forward on the stick.


    Andrew.

  21. #21
    Charlie Longley's Avatar
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    Pawnee is the easiest tailwheel airplane in the world to fly. But with a little brakes this can happen. I cringe a little when people ask how much they can push the stick forward.....
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  22. #22

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    How high the tail

    Andrew, you're right-on with old-new school: two different cultures. W/Cmdr (Rtd) Gordie Steeves, a Sopwith Camel pilot with RFC who was shot down in World War I, taught my father to fly a Tiger Moth before World War II to serve in Bomber Command, and then me in a 65hp J3 on floats in 1953. He was acclaimed as one of the most accomplished light aircraft pilots in the country.

    Commenting on tricycles and the drive-them-off, drive-them-down of post-war flying promotion, Gordie would say three-pointers under normal conditions because even with crosswinds the tail will have to come down some time anyway. (My son, retired recently as chief pilot major corporation, flew Gordie's ashes out over the Atlantic to be buried at sea.)

  23. #23
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    Quote Originally Posted by King Brown View Post
    Andrew, you're right-on with old-new school: two different cultures. W/Cmdr (Rtd) Gordie Steeves, a Sopwith Camel pilot with RFC who was shot down in World War I, taught my father to fly a Tiger Moth before World War II to serve in Bomber Command, and then me in a 65hp J3 on floats in 1953. He was acclaimed as one of the most accomplished light aircraft pilots in the country.

    Commenting on tricycles and the drive-them-off, drive-them-down of post-war flying promotion, Gordie would say three-pointers under normal conditions because even with crosswinds the tail will have to come down some time anyway. (My son, retired recently as chief pilot major corporation, flew Gordie's ashes out over the Atlantic to be buried at sea.)
    What an incredible flying legacy of generation lessons passed down... Thats how we learn..

  24. #24
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    A few things to address:

    No speed, rpm, or any other fixed number is relevant to this situation- we don't know his airplane.

    1. the amount of angle you can achieve without prop damage is a function of arm between the rotation axis and the prop tips- 3" extended gear will allow more than standard gear, as will 3" forward gear.

    2. The prop length will factor into this- long prop means less clearance

    3. landing surface will change this- tall grass or snow? might be in the prop at 3 point

    4. Bungee strength/tire pressure- you will compress the gear/tires once you begin producing downward lift.

    Every aircraft is different.

    The suggestion to lift the tail and sit inside to see where that point of damage might be is a good one. But leave the prop about 4" off the ground to allow for tire and suspension issues. If you have a hoist lift it up until the prop is 4" off the ground, (hang a bucket of water off the tailwheel to prevent a sudden tip) and climb in. How does that feel????

    If you want to, you can roll them over, any airspeed, any surface, any power setting. It just takes some effort or bad luck


    Now, old school to new school:

    Seems to me, all the reading I have done (not flown biplanes or the really cool old stuff), breaks were really not on those birds. Also, they had a drag for the tail, the tires were essentially bicycle tires and fields were what we call Off-Airport.

    Add that up, and yes, if I come in with a cub on a rough strip with my brakes failed, I am going to drop it down at full stall with the stick sucked into my gut.

    Equipment has evolved and our technique with it.

    Another point on this, we are focused on very short strips for our equipment, with heavier aircraft and much less wing. Let's see you bring a Moth over the trees at the angle we do with cubs, then get her stopped as short. Some might, but I imagine it would take a falling leaf into a full stall landing and scare the goodness out of passengers
    I don't know where you've been me lad, but I see you won first Prize!

  25. #25
    PerryB's Avatar
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    Maybe I'm missing something, but I don't see how running it down the runway on the mains under power is any form of practice for wheel landings.
    After Monday and Tuesday, even the calendar says WTF !

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    It is, though. And it is excellent for directional control instruction. Harvey Plourde wildly disagrees with me.

    Here's my take: I teach wheel landings only after full stalls are mastered. In a Cub I teach forward stick on takeoff only after a 3-point takeoff is mastered.

    For the first wheel landings I teach a little bit of power, fly it on, and think forward pressure when the main hits.

    Later on, we get to power off wheelies on the back side of the mains.

    My directional control lesson is 45 minutes on the ground, with me handling the stick and power, and the student sweating the rudder pedals. The lesson is complete when I can put her on one main, then the other, and she stays on the centerline. Harvey says this is dangerous.

    One of the surprising things, to me, is that one can touch down with brakes on, at least in a Cub, and not go over on your back as long as you can get the student to release them before you get too slow. At speeds below about ten knots a full sudden application of brakes will cost you a prop. Totally surprising is that it can happen at really slow speeds.

    Had an instructor friend jam the stick full forward on a wheel landing. Scared the crap out of me, but otherwise no problem. I talked him out of that in a hurry.

    I am personally in the school that says a full stall landing is best. You have to get the tail on the ground some time - why not when still at flying speed, where the rudder is slightly more effective. But when it is 20 knots at 90 degrees to the runway and gusting a wheelie with the wingtip on the ground is just about the only way.

    Just opinion, but I have done a lot of Cub crosswind landings over the last 55 years.

  27. #27

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    "The lesson is complete when I can put her on one main, then the other, and she stays on the centerline. Harvey says this is dangerous".

    Bob, what would be dangerous about that? Plenty of control authority remaining.

  28. #28

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    Quote Originally Posted by bob turner View Post
    In a Cub I teach forward stick on takeoff only after a 3-point takeoff is mastered.
    This is a bit of thread creap... Bob, as a newer Cub owner I am curious if your takeoff off progression is simply a progression to the ultimate skill or if you see a different takeoff technique should be used depending on the situation. What is your point of view on 3pt vs tail low vs tail high takeoff?

    I have been taught two takeoff techniques by two different CFIs. (1) stick goes forward with throttle and then hold a tail low attitude with wheel a "foot" off the ground, and (2) stick back for roughly first 3 to 5 seconds then ease stick forward until the same tail low attitude is achieved.

    Interested to hear a little more "below the surface" about when to employ each technique.

  29. #29
    Cub Builder's Avatar
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    Quote Originally Posted by Deaner View Post
    I have been taught two takeoff techniques by two different CFIs. (1) stick goes forward with throttle and then hold a tail low attitude with wheel a "foot" off the ground, and (2) stick back for roughly first 3 to 5 seconds then ease stick forward until the same tail low attitude is achieved.

    Interested to hear a little more "below the surface" about when to employ each technique.
    When I first started flying taildraggers (65 hp champ) I used technique #1. When I got my Starduster 1, the first time I used that technique in some soft grass (shove in the throttle and stick forward at the same time), I went back and counted 38 little strikes in the grass and thatch and had the paint scrubbed off the very end of my prop tips. I have used technique #2 ever since. First get some authority with the elevator before you try to use it to lift the tail.

    -Cub Builder
    Last edited by Cub Builder; 04-28-2016 at 05:33 PM.

  30. #30
    Eddie Foy's Avatar
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    One thousand one, one thousand two..lift the tail
    One thousand one, one thousand two. rotate and drop full flaps.

    Best technique I have found to get off in the shortest distance.

    With lots of runway it is more like three potatoes, lift the tail. Then let it fly off with minimal back pressure.

    IMHO! YMMV!
    "Put out my hand and touched the face of God!"

  31. #31

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    I actually measured takeoff distances with various techniques. With the J-3 and Super Cub I could not measure a difference.

    With the C-180, by the time you get the tail off the ground, a three point takeoff would have had you airborne. It is dramatic.

    With low powered Champs and at least the UPF-7, you may want to raise the tail a bit to avoid lifting off too soon. The Cub is controllable well below stall speeds, so I find it better to lift off early. In a Cub, I just relax the back pressure and let it fly off.

    Most of my students with prior taildragger experience hav never - ever - done a takeoff from a 3-point attitude. I have seen 180 drivers lower the flaps for takeoff, then get it up on the mains until 70 indicated, then climb out at 90 with flaps extended until 1000' agl. They say it climbs faster that way. The laws of basic physics do not back that up.
    Last edited by bob turner; 04-28-2016 at 05:35 PM. Reason: Trying to fix typos. So far no luck

  32. #32
    Barnstormer's Avatar
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    aktango58 is correct when he says ďEvery aircraft is different.Ē


    Congratulations on building and flying a SQ2. Itís roots are Super Cub but itís design is highly modified making it a unique aircraft to fly. I havenít seen yours so canít speak to its exact design but I can speak of mine.


    Its tail feathers are bigger then a Super Cub so have more authority. The flaps are double-slotted fowlers that extend to 62 degrees where they both can blank out the elevators fairly effectively while at the same time trapping air under the wing to such an extent that the tail will lift under the right circumstances. Iíll leave it up to you to imagine what can happen if allowed.


    Stay off the payment as much as possible, it has nothing to teach you and can delay your becoming comfortable on turf and off-airport (land pavement just enough to stay proficient and not fear it). Wheel landings are a very important part of off-airport flying but running down a runway pinning the plane on the ground teaches nothing.


    Instead find a long, unobstructed grass strip or better yet a beach, long sand or gravel bars. Set up to land, then as soon as the mains are on pick up just enough speed to fly the tail, not enough to fly the plane. Wheel along for a bit then add just enough power to get airborne, back off on the power to land, add just enough power to fly the tail, wheel along for a bit and then back in the air and repeat the process. A few thousand times should be sufficient.


    An added bonus you will be gaining a greater understanding of just when the plane can fly and when it canít which will help you become very precise to where your wheels touchdown and lift off.


    IMPORTANT: Donít land on surfaces you are unfamiliar with, especially sand.

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    Iím very fortunate to have an area close by here in Texas where I can do this for probably 10 to 15 minutes at a time. There are wires and fences I have to avoid. Here is a video that illustrates what Iím talking about (you may have seen it before):

    Have fun!




    Phil Whittemore

  33. #33
    L18C-95's Avatar
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    Phil that is an incredible video, thanks for re posting. Brian Lansburgh at Tailwheelersjournal.com has some interesting instructional exercises which build up wheel landing skills.


  34. #34

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    Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
    165 pound pilots, identical payload (light), on grass, 70įF, 8 kt wind straight down the runway.
    J3 avg 65-75 feet
    PA18 avg 190-200 feet.
    The J3 was about 25 feet in the air when the 18 broke ground.
    Some of that was pilot technique.

  35. #35
    Gordon Misch's Avatar
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    Quote Originally Posted by JimC View Post
    Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
    165 pound pilots, identical payload (light), on grass, 70įF, 8 kt wind straight down the runway.
    J3 avg 65-75 feet
    PA18 avg 190-200 feet.
    The J3 was about 25 feet in the air when the 18 broke ground.
    Some of that was pilot technique.
    I did the same years ago - my 150 hp PA-12 and my friend's 90 HP J3 side by side on firm, sandy beach. Dead even.
    Gordon

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  36. #36
    aktango58's Avatar
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    Quote Originally Posted by JimC View Post
    Bob, we've tried takeoff in an O-200 powered J3 vs a 160 hp SuperCub.
    165 pound pilots, identical payload (light), on grass, 70įF, 8 kt wind straight down the runway.
    J3 avg 65-75 feet
    PA18 avg 190-200 feet.
    The J3 was about 25 feet in the air when the 18 broke ground.
    Some of that was pilot technique.
    Some?????
    I don't know where you've been me lad, but I see you won first Prize!

  37. #37
    Cub junkie's Avatar
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    After reading all the responses to this thread which is named "can the tail get too high" my answer is yes. The tail is too high when the prop strikes the ground.

  38. #38
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    I was riding in the back seat of a 7GCBC one time when the owner/pilot decided to practice a wheel landing. From where I was sitting it seemed to be at the proper attitude, yet we both heard a small ting, ting, ting from forward of the engine. Fortunately the damage was minor, but the prop did touch the pavement.

    Trying to hold an airplane on the ground beyond normal flying speed can only lead to eventual trouble. As the speed builds, the lift on the wing builds, the stick has to be pushed further forward etc., etc. Eventually the prop starts to turn green (if on grass). This maneuver proves nothing beyond the entertainment factor. If your airplane is heavily loaded sometimes it is important to accelerate to a higher than normal speed in order to be able to climb out of ground effect. Of course this depends on what type of airplane we are talking about. Personally I like to get the tail just above the ground letting the plane fly off when it is ready for normal take offs.
    N1PA

  39. #39

    Join Date
    Oct 2012
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    My elevator has never had the authority to lift the tail enough to create a problem. Go lift your tail high enough to threaten prop-ground contact and you'll see why. My new plane will use an 86" prop but maintaining "normal" prop clearance is in my best interest.

    ß 23.925Propeller clearance.Unless smaller clearances are substantiated, propeller clearances, with the airplane at the most adverse combination of weight and center of gravity, and with the propeller in the most adverse pitch position, may not be less than the following:
    (a) Ground clearance. There must be a clearance of at least seven inches (for each airplane with nose wheel landing gear) or nine inches (for each airplane with tail wheel landing gear) between each propeller and the ground with the landing gear statically deflected and in the level, normal takeoff, or taxing attitude, whichever is most critical. In addition, for each airplane with conventional landing gear struts using fluid or mechanical means for absorbing landing shocks, there must be positive clearance between the propeller and the ground in the level takeoff attitude with the critical tire completely deflated and the corresponding landing gear strut bottomed. Positive clearance for airplanes using leaf spring struts is shown with a deflection corresponding to 1.5g.
    (b) Aft-mounted propellers. In addition to the clearances specified in paragraph (a) of this section, an airplane with an aft mounted propeller must be designed such that the propeller will not contact the runway surface when the airplane is in the maximum pitch attitude attainable during normal takeoffs and landings.
    (c) Water clearance. There must be a clearance of at least 18 inches between each propeller and the water, unless compliance with ß 23.239 can be shown with a lesser clearance.
    (d) Structural clearance. There must be—
    (1) At least one inch radial clearance between the blade tips and the airplane structure, plus any additional radial clearance necessary to prevent harmful vibration;
    (2) At least one-half inch longitudinal clearance between the propeller blades or cuffs and stationary parts of the airplane; and
    (3) Positive clearance between other rotating parts of the propeller or spinner and stationary parts of the airplane.

    [Doc. No. 4080, 29 FR 17955, Dec. 18, 1964, as amended by Amdt. 23-43, 58 FR 18971, Apr. 9, 1993; Amdt. 23-51, 61 FR 5136, Feb. 9, 1996; Amdt. 23-48, 61 FR 5148, Feb. 9, 1996]

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