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Thread: Building a Nieuport 11...

  1. #771

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    Quote Originally Posted by Frank Giger View Post
    Oh, that's me bouncing the landing and making a general mess of things.
    Landing was fine. I was thinking of the swerving I saw immediately after the tailwheel settled. I've experienced that

  2. #772
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    Quote Originally Posted by Saville View Post
    Landing was fine. I was thinking of the swerving I saw immediately after the tailwheel settled. I've experienced that
    Two things usually at play, here. First, the tail settling down takes the rudder out of the direct airflow...the slipstream/prop blast is somewhat blanked by the fuselage itself.

    Second, the comparative "gearing" of the rudder control and the tailwheel control is likely different. That is to say, a ~1" displacement of the rudder pedal with the tailwheel off the ground and the rudder providing yaw control is different from what is produced when the tailwheel itself is firmly on the ground.

    A good example of this is the original Fly Baby prototype, N500F. When I started flying it, I noticed the plane would tend to yaw as the tail came up on takeoff or as it settled down to the runway on landing.

    Turns out this was due to a quirk in N500F's tailwheel control system. On a Fly Baby, the rudder pedals are connected directly to a flat rudder horn. At the bottom of the rudder is a second horn, which connects to the tailwheel horns via springs. Here's a rough sketch:


    N500F had that system....but, at the time the plane had been converted to floats, the lower horn on the rudder had been extended ~2-3" per side to provide better control for the water rudder. When the plane had last been restored (about three years prior to my joining the club), the TAILWHEEL springs were connected to these extended attach points. Which gave the tailwheel more effectiveness.

    I swapped the tailwheel control springs to the upper pair of holes, and it was a lot better.....

    Ron Wanttaja

  3. #773

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    Another factor is the location of the aircraft CG when the tailwheel is on the ground. If the CG shifts aft a considerable amount, the "heavy" tail will certainly try to wag the dog more than a more forward CG. Aircraft with relatively tall gear such as our WWI wannabes are subject to considerable CG shift when the tail hits the ground. One remedy is aggressive rudder immediately after the tail touches down before the rudder loses aerodynamic authority. I will sometimes use full rudder for a second or two to catch a swerve before it can develop.
    This is a matter of pilot proficiency and acclimation to the particular aircraft and improves with practice. Fly often.
    Sam Buchanan
    EAA Technical Counselor
    The RV Journal RV-6 build log
    Fokker D.VII build log

  4. #774

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    Yep, it's affectionately called "The Nieuport Stomp" in our circle.

    In the case of the video, that's all me. I was off line to the left, corrected right, and was slow adjusting back left...so gave it a bit too much. Then it was a matter of working the pedal to the wheel to stay on the runway and simultaneously keeping the wing tip off the pavement.



    The grooved pavement of my runway can be challenging, as it's very sticky and rough at the same time. Landing on smooth pavement is easier for some reason. I haven't landed on grass with her yet.

    On charging, I may not have a problem at all. Digging into Harley-Davidson forums, it should be putting out 14.5 to 15 volts at RPM, which is what I'm indicating. So it's likely that my last voltage regulator wasn't working properly at all and I was running off battery most of the time! Most of my flights have been pretty short, and charging the battery was pretty common for me. I wrote it off to the plane sitting for a month, but that might not have been the case.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  5. #775
    rwanttaja's Avatar
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    Quote Originally Posted by Frank Giger View Post
    On charging, I may not have a problem at all. Digging into Harley-Davidson forums, it should be putting out 14.5 to 15 volts at RPM, which is what I'm indicating. So it's likely that my last voltage regulator wasn't working properly at all and I was running off battery most of the time! Most of my flights have been pretty short, and charging the battery was pretty common for me. I wrote it off to the plane sitting for a month, but that might not have been the case.
    Frank, do you have a backup power source for your ignition? I see a lot of accidents (~2 per year) caused by power issues to engine ignition/control boxes.

    Ron Wanttaja

  6. #776

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    Nope. If the battery goes to zero the big fan stops.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  7. #777
    rwanttaja's Avatar
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    Quote Originally Posted by Frank Giger View Post
    Nope. If the battery goes to zero the big fan stops.
    Hmmm. Wonder if you could put in an emergency backup capability using alkaline batteries. Put in one of those covered switches so that the normal battery is connected in the "off" position, but the battery pack goes to the ignition system if the cover in thrown back and switch is thrown.

    Might be able to get by with AA batteries; Amazon sells an 8-cell holder for $7. Don't know how much time it'll give you, but even a minute is worth it, sometimes. Test it at each Conditional inspection and replace with fresh batteries.

    Ron Wanttaja

  8. #778

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    And now, in the category of "of all the dippy sh*t," I may not have a problem at all.

    The previous voltage rectifier/regulator was clearly flaky, either putting out a bunch of charge or none at all. So I replaced it.

    Now I'm showing between 14 and 15 volts when the engine is running, topping out about 15 at full RPM. So I got to digging around the Harley-Davidson forums (since I finally figured out the whole system is HD), and guess what? The system should be throwing around 14.5 to 15 volts, depending on RPM and battery charge. It could be doing what it was supposed to all along.

    I wigged out, naturally, since I haven't seen voltage go up like that before, and the aircraft I've flown previously didn't have a voltage gauge. Plus I smoked a battery in the hangar with the old rectifier/regulator.

    Since the bog standard automotive voltage gauge isn't exactly a precision instrument, I'm going out Wednesday morning with a proper volt meter to see just what it's pumping across the terminals. Any less than 15 volts at RPM's means all is well and I'm a Nervous Nelly. But I'm still glad I put a switch on it.

    It also means I'm an idiot, as it means that previously I'd been flying off just the battery and not noticing the voltage go down and down. The short duration of my flights thus far were the saving grace. What I chalked up to a small battery sitting for a month and needed a charge wasn't that - it was low because I ran it down. Indeed, on the day where I saw the battery charge go down it was on the second flight - she'd already been up for a solid hour, back down and sat for another hour. And even then it didn't start noticeably dropping until I was up and had flown away from the airport.

    Pretty interesting decision tree at that point.

    I'm about six or seven miles (which, easy math, is about six or seven minutes) from the airport at around 2,500 feet AGL. I have a working engine at 11.5 volts indicated and slowly dropping. So point the airplane back at the airport, go into a gentle climb with a minor bump of the throttle (the coils are going to suck the same amount of juice pretty much the same between 2,500 RPM's and 2,700 RPM's), and keep a look at what's below. Reduce throttle when I'm at the glide to the airport, about two miles out, bring it close to the strip at pattern altitude, shadow it, and do the short half circle to the end to a bouncy landing (yep, that "flight after repair" was my sort of cautionary landing). If she'd of gone dead at any point I'd of made the field, though it would have been with a tail wind (oh, no, the horrors of a two mile an hour tail wind! Could I have survived?). She had a little over ten volts when I taxied up to the hangar.

    One would think there'd be a manual for all this stuff, but there ain't none. Not knowing how much charge should be showing with the system running could have really hurt me - and I didn't know that I didn't know. I just assumed that the little volt meter would be nice and steady in the upright 12v position the whole time, like it does in a car (well, with a little nudge to the right).

    I've got a message into Valley Engineering on what the voltage meter should read in flight and at RPM; I was too ignorant before to ask the correct (if obvious) question on the matter.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

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