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Thread: Building a Nieuport 11...

  1. #611
    Sam Buchanan's Avatar
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    Quote Originally Posted by rwanttaja View Post
    if the fan ever stops for real, I want to be accustomed to the way it drops.
    The steepness of the descent can be startling to the pilot who has never experienced the way a high-drag, low-mass aircraft "glides". The windscreen is filled with terra firma and the pilot must stay on speed and resist the impulse to raise the nose. Pilots with experience only in heavier aircraft have come to grief when they raised the nose to "stretch" the glide and used up all the airspeed....

    There is no reason to dislike flaps, they are a control surface same as elevators and ailerons. Learn to use them and appreciate the way they can expand the flight envelope.
    Last edited by Sam Buchanan; 07-18-2016 at 01:47 PM.
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  2. #612
    rwanttaja's Avatar
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    Quote Originally Posted by Sam Buchanan View Post
    The steepness of the descent can be startling to the pilot who has never experienced the way a high-drag, low-mass aircraft "glides".
    "Notice that they do not so much fly as...plummet. "
    - Monty Python's Flying Circus

    Ron "Baaaaaa" Wanttaja

  3. #613

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    I wanted to thank y'all for your input first and foremost!

    The whole reason for continuing the thread on the aircraft into flight testing is to hear from the voices of experience; it's one thing to draw up a plan on paper and quite another to execute the primary steps in a prudent manner.

    I'm taking the approach to testing the same way I did the build - it's done when it's done, and slowing down the process when unsure exactly how to proceed is the best course of action.

    Indeed, I'm now (at ten hours) at the Confidence in General Flight stage, where I know how she acts overall in the fundamentals - takeoff, turns, climbs and descents - and so I can work on other steps.

    I've done some power off glides, of course, but not extensively. The most striking thing is with a high drag aircraft like this is the feeling that a giant hand has just grabbed the entire aircraft to slow it down all at once.

    Determining best glide has me scratching my head when it comes to the science. I know what feels right - somewhere around 45 mph IAS (1.3 Vso, based on a 35 mph stall speed, which might be a high guess) - but I'm unsure on how to validate that.

    I do know one thing - stretching the glide is a fool's errand in large part with my Bebe - so being fully aware of landing spots in all directions is key to flight.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  4. #614
    Sam Buchanan's Avatar
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    Quote Originally Posted by Frank Giger View Post
    Determining best glide has me scratching my head when it comes to the science. I know what feels right - somewhere around 45 mph IAS (1.3 Vso, based on a 35 mph stall speed, which might be a high guess) - but I'm unsure on how to validate that.

    I do know one thing - stretching the glide is a fool's errand in large part with my Bebe - so being fully aware of landing spots in all directions is key to flight.
    Frank, one method I've used to get a handle on glide speeds, and this is admittedly more practical than scientific, is use the long runway we both have at our home airports. This needs to be done in calm or very low wind conditions if possible.

    Set a target altitude and speed for the tests, for example, 400' AGL @ typical cruise speed. Approach the runway threshold in level flight at your target altitude and chop the power just as you reach the end of the pavement at the threshold. Immediately assume the first of the airspeeds you wish to test, say 45mph. Descend to a landing with no power (this may take a little practice) and take note of where on the runway the landing occurred. Repeat the test at various glide airspeeds, always beginning at the same altitude and cruise speed and cutting power at the end of the runway.

    As a bonus, you will be pleased to note how much more consistent your landings become after this exercise.

    After you have explored several speeds, you can look at the runway markings on Google Earth to determine how far down the runway the landings occurred. This not only gives you a good idea of the best glide speed for maximum distance, but you can calculate descent rate using the time stamp on your video camera. If you still have a lot of unused runway in your tests, you can repeat at a higher target altitude, maybe even your customary cruise altitude.

    If you really want to explore the envelope, run the test with the aircraft flying in the opposite direction of the landing runway and offset a couple hundred yards. Flying a descending 180 turn will probably be closer to what you would encounter in an actual unplanned landing.

    Maybe this will give you some ideas for running real-world tests of glide speed. Once you have done this, you can draw the mental cone around your aircraft to determine where you could land in case of emergency. Be sure you allow for at least 180* of maneuvering in establishing the cone.

    The base of the cone will be very small.
    Last edited by Sam Buchanan; 07-21-2016 at 08:52 AM.
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  5. #615
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    Frank, take a look at a program called GPLIGC (Google it; I'm away from home without my bookmarks. With a GPS receiver with a pressure altimeter (I use a Garmin 60Csx but there are other options), you can run the GPS track into GPLIGC and get a plot that you can analyze for climb and decent angles, etc. It's intended to analyze sailplane performance but it works great for powered planes, too.

  6. #616

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    I'll take a look - thanks for the advice!

    Right now I'm using CloudAhoy, which is just mindboggling in how simple it is to use and the information it gathers and spits back out - 3D flight track, TAS and IAS based on GPS track and wind reports from local stations, plus wind itself on the route, etc.

    The bad of it is that if I ever do something wrong there's a pretty definitive record of it. Heck, it knows if you landed off of the center line and how much by!

    Fun flying today! Winds were light and variable, bumps were tolerable, and I just had a ball.

    Did some Thottle Back stuff; woof, there's a lot of terrain filling up one's view to keep reasonable airspeed - it's like a big hand just grabs the plane from behind. I did it a couple times feeling out glide angles and it's actually not as scary as I thought it might be - the cone isn't as tight as I though. Did a 180 as well to see how much altitude was lost and that wasn't really all that bad compared to a straight glide. One just has to realize that when committing to a landing spot, commit to it and if there are two of equal okay-ness, pick the closer one.

    And, as always, altitude is one's friend.

    I also did my first cross country flight in the Nieuport! I was tooling about and realized two things: I was really close to Pell City (PLR) and I was getting a bit barn broke to my home airfield. So I landed pretty crappy, trying for a sharper angle and a three pointer, but it was at the far end and nobody saw it. Taxi up, park next to all the CAP planes that were there for check ride training tomorrow, and walk in. I learned to fly at Pell City (okay, St. Claire County), and it was familiar ground, so to speak.

    What I didn't expect was the warm reception from actual people at that airport. I had forgotten that pilots actually hang out there and talk to each other (Talladega is a fine airport, but a ghost town). So my fifteen minute bio-break and stretch took an hour of folks swapping stories and looking over my airplane.

    It came time to take off and I realized two things:

    1) The winds favored taking off at the end by the FBO.

    2) There were six folks grinning from either the ramp or the air conditioning of the FBO. I figured the two taking shade under the wings of the CAP C172 were the Russian judge types.

    Might as well get it over with. I can always just avoid coming back for a few months if I make adventurous looking, and so with a shrug I advanced the throttle AND DID A PERFECT STRAIGHT ON TAKE OFF. No rudder swish, she just smoothly walked up into the air.



    That's the sign of both a great woman and a fine airplane - she'll give you hell one on one, but when there's people watching she'll back you to the hilt.

    Did a fine wheel landing with a steeper approach at my home airport and put her up.

    And noticed that I hadn't actually turned the cameras on to record.

    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  7. #617

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    In my last post-flight inspection I found the engine baffling in the front was rubbing the cowl in such a way that the cowl started to crack upwards from the contact point.

    And the tail wheel once again was loose from the mount, flopping from one side of the wheel to the other.



    So I had my son drive me up to the hangar in his truck "just to get out of the house," with his rote admonishment that he would do zero work on the aircraft before accepting to carry me.

    His barely concealed secret fear is that he would do something wrong that would result in a crash has been pretty firm in this matter.

    So I drilled some stop holes at the ends of the half inch long cracks and made up some patches to rivet over them - one of the advantages to a Nieuport 11 cowl is that one ends up with a third of the starting bowl as scrap - to go over them.

    To my surprise there stands my son with the drill in his hand when I say I want to hole the patches first, then align and place them before drilling the cowl. I guess he figured it's non-structural enough to be safe to do.

    So he drills the patch and after I place them, drill the first hole, rivet it to keep it in place, he offers to drill and rivet the rest of them!



    The rivet lines aren't exactly perfect, but why should I change the standard of craftsmanship that has made the aircraft airworthy now?

    We notched the baffling where it was hitting the cowl to where it isn't any more. I'm not too worried about it, as I'm way ahead of the cooling curve with my engine, and the gap is right at the front.

    On the tail wheel, I had something of an epiphany. Robert had put the bolt in with the head on top and the nut on the bottom. The problem is that because the tail of the bolt is downwards, it has be short to clear the wheel, and working the wheel is loosening the nut, even with washers.

    There is no reason I can see where it has to be that way. I got a longer bolt and placed it nut side up with two washers on both ends of the mount. Now the tail wheel mount rotates without the bolt or the nut rotating with it.

    I'll see if it works out okay while I come up with a new design for the assembly.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  8. #618

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    My Nieuport 11 - now with 70% more gun.



    The supports from the front bottom mounting points to the slip ring at the front of the receiver have to be measured and cut, the mounting bolts need trimmed, etc., but it's coming together in a solid mount.

    I'd of kept going, but I'd been dinking around with the gun and some other stuff on the aircraft for four hours and was starting to wilt.

    Pity, it was starting to cool off:

    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  9. #619

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    A little show and tell:

    So here's the gun mounted with some trimming and painting to do - hopefully it'll be more difficult to explain what I did after the finishing touches are done!

    In the front, the all-thread bolts run through the leading edge material just behind the spar, reinforced by an aluminum strip.



    There are four supports on these bolts - two up to the barrel, which is easy to see, and two that run to the bolt that runs through the center section in the rear.



    The whole thing seems pretty solid, and hopefully the weather will cooperate tomorrow morning and I can put some wind on it. The reason these are indoor shots is due to rain just outside the hangar.

    Next up is that cowl repair:



    The split behind the plate there was stop-drilled and this is the cover...there's a matching one on the other side. I also cut the baffling back to where it's not hitting the cowl in the front even a little.

    Also, sigh. Somewhere along the last few times with the airplane I put a little rip in the fabric on the right fuselage near the bottom. So that got a patch. I don't mind doing fabric repairs, but I'd love to know how it got there in the first place.
    The opinions and statements of this poster are largely based on facts and portray a possible version of the actual events.

  10. #620

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    A few flying notes:

    My rate of climb seemed a bit wimpy yesterday. Nothing in the "golly gee maybe I ought to land" range and the engine was doing everything it's supposed to, but it was a bit lazy.

    Take offs were some of the best yet - I've found the correct amount of up elevator to get her to step into the air rather than leaping - but my landings were kind of wonky. Usually it's the reverse, of course, where I swish it around going up and walk it onto the pavement going down.

    More vexing was the fact that I've also found a better approach and angle from my super shallow technique, dipping back to what I used to do in the Champ. It's more a large curving descent than to turns on a box, with "large" more in line with the short Champ pattern.

    So instead of kissing the pavement with a main and settling the tail down in a straight forward manner I was tapping the main and getting a minor bounce, which had me setting up for another try and a little bounce. I wound up going around at Pell City just to eliminate the frustration factor and keep from "fixing" the problem with a ground loop. I managed to work through it by putting her into three point position and dancing between the three wheels.

    On a hunch I tuned back to the airport weather station (which I had hit to confirm wind direction when approaching the field) and the answer made me laugh.

    ...density altitude three thousand two hundred feet... the computer man said. Quite a bit of difference from the 480 above sea level actual.

    The way to my home field was long as I just did some field survey and the landing was much better, though a bit bouncy. I write that off to the collection of people outside the FBO waiting on a charter flight and watching more than anything else, though.

    I'm my own worst critic, of course. One of the pilots on the field said my landing looked good before I could apologize for being crappy.
    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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