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About zadwit

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  1. zadwit added a post in a topic Elevator trim tab safety   

    another way to  prevent this  is put a mass balance weight on the tab to balance it 100%. IE with the tab control disconnected, the tab should just  ride along. Other wise is can be a dangerous situation.. IT caused  many a crash on the beech craft Bonaze Vee tail because the 1/16" trim tab cables would rust and fail allowing the elevator to flutter causing  the stablizer to  flex wildly up and down and few times and rip off. It is nothing to mess with. I f you look  at teh Dehavilland HC2 Beaver, they have the mass balance weight on the ailerons.
    The Taylorcraft L-2 has it as well on the elevator tab. Most Cessna 120, 140, 170, 172 dont need it because a cable chain drived a gear box that has a push rod that goes to the elevator tab.
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  2. zadwit added a post in a topic 1999 kitfox IV engine change   

    My plane is a 1999 SKystar Kitfox Classic IV with a 503 air cooled engine.
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  3. zadwit added a topic in Technical tasks   

    1999 kitfox IV engine change
    What parts do I need to remove my Rotax 503 air cooled and install a Rotax 582 liquid cooled engine? Can I reuse my engine mount?
    Where do I get a radiator, the hoses and parts and pieces to install a new 582. I think I will buy a new 582, any suggestions where to buy one???
    My 503 has 154 hours sine new and about 2 hours since decarbon so after I get the 582installed, Ill sell the 503 I think...Any comments or suggestions welcome please!!!
    Thanks, Mark Smith in Davenport, Wa.
    • 5 replies
  4. zadwit added a post in a topic Kitfox 4 fuel tank kreem peeling   

    I have one installed fibreglas tank (1999 SKystar Kitfox Classic IV and the other tank is removed and the wing covered...... think both tanks have that Kreem sloshing compound.....
    Are new poly tanks available to just replace these with rather than mess around trying to clean and reslosh them???
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  5. zadwit added a post in a topic Need some gear measurements   

    When I talked to Dean Wilson a few months ago about placement of the axle centerline on a tail dragger he had some interesting info.
    He said when the JN4 Jenny first came out, it had no brakes and on tail wheel, only a tail skid so the axle center line was placed real close to the loaded flying CG. This worked fine until brakes were installed then the planes started getting nosed over so the axle centerline was moved forward. He told me about the 12 degree angle. IF you level the plane, drop a plumb bob thru the CG on the wing and then measure off that vertical line forward 12 degrees is about all you want . More than that makes the plane hard to control on the ground.
    A lot less and you are prone to nose over... There has to be  a happy medium especially if operating on skis, plus wouldnt it be nice if you had more precise control on takeoff without the damn plane trying to Eat you all the time?????!!?
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  6. zadwit added a post in a topic Need some gear measurements   

    On the Ridge Runner 1 the axles centerline is so far forward of the all up loaded CG that if you try to lift the tail on takeoff,it will try to eat you!!!! and had eaten many a test pilot......
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  7. zadwit added a post in a topic Need some gear measurements   

  8. zadwit added a post in a topic Need some gear measurements   

    There is a formula that aircraft designers use for TW aircraft. The determine the aft CG loaded for flight, level  the aircraft and draw a line vertical thru the CG. Then they measure 12 degrees from the CG forward and that line shoujld  not go thru the axles center line. If it does, it make the airplane very tail heavy and hard or nearly impossible to control. Ironically I read this in Design for flying by Dave Thurston, aeronautical engineer and a few days before I read it I was talkeing to Dean Wilson about trouble with ground handling on my Ridge Runner 1. Guess what, the Axle center line is 20 degrees maybe a little more ahead of the Datum, with plane loaded aft CG ready to fly on the Ridge Runner which is why it is such a squirrel on the ground. The Main gear axles are 8.75" fwd of the WLE on the Ridge Runner 1. When loaded to most fwd CG the angle from CG to axle is 10 degrees but it will never be there bevause the fat pilot is 22" aft!!!! so most of the time the wing CG is at the aft limit of 16 inches.........
    The tail is slow to come up even with a 503, a bigger engine than designed.. and it wanders all over the runway. Does not want to go straight. The closer the axle centerline is to the loading flying CG, the more stable ground handling, easier to nose over, but tail  comes up quik.  Partly at Play on the PA-180150 is the engine is canted down on the mount, the engine is powerful and so the thrust line is above the axles quite a ways which all adds to lifting the tail quickly.  COnverted Tri pacer to tailwheel were terrible  on skis because you could not get the tail up out of the snow so takeoff runs for very long. The PA20 was not as bad because it had more down elevator travbel,, a lot more down travel.
    Same problem  on the TexasTail Dragger Cessna 150, the gear so far fwd impossible to pickup the tail on takeoff so in the snow a real problem....
    I have not measured the angle on a PA 18 but I looked this info up. Datum is Wing Leading Edge (WLE)
    Axles centerline is 2" aft of the datum. Level the plane  and the axle will be 2" aft of the WLE, the CG  is still farther aft,
    CG range is 10.5" to 20" aft of the WLE on PA-180150
    YOu would need a scale dwg of a pa-18, mark the CG location fwd and aft, then draw a line 12 degrees thru the CG at the wing down towards the axles and see what it measures..
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  9. zadwit added a topic in Kitfox IV   

    Grove landing ger????or something else??
    I have standard Main Gear Legs on this 1999 Kitfox Classic IV with8" douglas wheels and  matco single piston brakes and King Fox tires.. I am pretty sure the axles  are 3/4" diameter.
    I am trying to decide if I should order up a Grove landing gear to replace what I currently have. Should I ask for 2" taller gear???? mainly I am looking for stability improvement on ground handling during takeoff and landings and I have read that lots of people say the wider gear legs improve the ground handling.. IF I order the Grove gear legs and install their 3/4" heat treated axles, I have seen a couple of them that have failed, probably due to overload however it looks to be the  weak link  in the gear .Still they were ground loops.....not normal loads....
    It would be nice to have a set of 8:00x6 tires and wheels for general flying and a set of 20" soft tundra tires for other stuff rougher places... 
    Just looking for ideas of how to proceed..... Is this the Grove gear I want or should I order something else????
    Kitfox Model 3 & 4
    Installation Instructions 
    Gross Weight: 1200 lbs.
    Weight:  24.3 lbs.
    Material: 7075-T6 Aluminum
    Axle Bolt Hole Pattern: Type 1
    Includes Gundrilled Brake Line
    P/N 1021-3   Price: $1,995Thanks, Mark Smith in Davenport
    • 11 replies
  10. zadwit added a post in a topic "FOXY FLAPPER" FOTOS   

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  11. zadwit added a post in a topic Making a new set of skis   

    Generally straight skis are best for performance esp in deep snow plus you are removing the weight of the wheels when you install straight skis.
    Out where i live there is 3 months of deep wind drifted snow, the airport is plowed mostly but no place for straight skis plus having wheels under it allows me to fold the wings and take it  home... A hangar would be ideal but the city here wants $250 a month to store in this hangar with  4 other planes and there are quesitons about working on the plane in the thats not such a good deal, the only other option is lease the ground and build a hangar but not sure I want to do that.. .I might get a wild hair and drag up and move someplace nicer to fly, less wind, the damn wind here reminds me of the north slope of AK in the winter......Davenport, Washington  30 sm west of Spokane in the wheatfield country...
    no cover.....mark
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  12. zadwit added a post in a topic Bad Landing, Failed Landing Gear, Missed Inspection?   

    I watched a Youtube Video of a guy landing a red kitfox and it swereved just a little one way then made a big sweeping groundloop with screeching tires and all but it didnt hurt it...the first thing the pilot did was look around to see  if anyone saw it!!! I laughed so hard my side hurt......
    WHen you screw up the first run of order is:
    1) did anyone see it?
    2) can I blame it on someone else?
    3) can I shit-can
    4 problem solved!!!
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  13. zadwit added a post in a topic Bad Landing, Failed Landing Gear, Missed Inspection?   

    I would like to get a set of wheel penetration skis to put under my classic IV main in case the engine quits or I am forced to land in a farmers field with 2 feet of snow.... 
    I just fly around  for fun by my self, not into any off airport stuff anymore, it always cost way too much $$$$$$$$$$$$$$$$$$$
    As a side note, the exwife has not seen my new plane and if I play my cards right and keep her entertained she feel sorry for pathetic me and make a small contribution to the

    "Markie FUnd"!!!!!!!!!keeping my fingers crossed....
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  14. zadwit added a post in a topic Making a new set of skis   

    In Kotzebue the sea ice would  get so  rough one eskimo had a super cub with wood and galvanized bottoms skis that had a nitrogenshock strut built onto it off of a SIngle engine  otter. He said he cojuld land on the roughes ice and itwas like landing on powder...
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