Activity Stream

Posts Activity Stream

  1. dholly


    Lol, who said I could afford it? As a business owner I wanted/needed the liability coverage, didn't care so much about the hull. Pretty glad I had hull coverage though when I bent the KF3, the ins. co actually made me buy it. I bot the salvage and walked away making money on that one. I would still recommend a new student or very low time pilot insure for both hull and liability until they get some time with their plane. 

  2. akflyer


    I don't know if I would let anything petroleum based touch the lexan.  One drop of blue Loctite shattered my door in about 5 minutes.  I use plexus or pledge to clean my windows.

    :BC:

     

  3. dholly


    Jim, I noticed that way back when and I agree it is odd to have one (?) C model in the middle of the D model Mk-IV s/n run. But then, I think the E model Bandits were like that, i.e. if someone wanted one during the D model production, Avid was all too happy to sell something, anything, as they neared the end of their corporate life. Similar to the mix 'n match fuse/wings/lift struts etc. philosophy they always pursued. That's why it is sooo dangerous for 'Mk-IV' buyers to assume based on seller assertions or s/n alone, gotta check the list!

  4. akflyer


    New student pilot training in an E-AB taildragger WILL be very costly from an insurance viewpoint. Maybe even impossible, as the aviation insurance co's only agree from time to time when they need to add risk to their insured pools to meet required minimums.  The ins. co. WILL require your instructor to have hours in type (10hrs min. in my case, IIRC). I succeeded with a KF3 TD , and then also got reasonable ins. for a KF4 TD before a CFI w/ 10,000hrs bent my Grove gear... which came out of my pocket after the CFI suddenly disappeared. Both EAA and NAFI provide flight insurance to CFI's training in experimental aircraft, I believe that includes their own as well as your aircraft. I recommend you ask if they provide their own ins. that takes precedence over your owner policy in the event of damage when they are PIC. Like many auto ins. co's, one aviation claim can follow you for years and cause higher premiums.

    insurance?  oh yeah, I forgot, you folks down south can actually afford it.  The premiums I was quoted made me shit my pants then I laughed.  I am not going to pay for a new plane every 5 yrs in premiums..

    :BC:

     

    1 person likes this
  5. EDMO


    They are very tight lipped on the details of testing and R&D.

    The STi wing is the same span, a very slight increase in chord and quite a bit thicker than the standard Riblett profile. 

    I seem to remember someone saying this was another Ribblett design, but I can't say that for sure. 

    If I remember from reading the Riblett letter long ago, I think he said the chord should be about 1.5" or 3" longer, but could be mistaken on that?  Thicker could give more lift, but slower cruise - maybe?  Look at Zenith.  ??? 

    I don't think that tips mean as much for STOL as they do for decreasing drag for cruise, although squared tips add more wing area / lift than rounded tips, such as Kitfox tips compared to Avid tips - the Short-wing Pipers have proved that with their aftermarket Hoerner style squared chord tips. 

    Not to sound at all like picking favorites, but I think that Dean made the rounded Avid tips like the Pipers as an economical way for the homebuilder to make them without having to buy fiberglass tips.  The Kitfox tips can be put on any Avid and should improve STOL a little by adding wing area and lift, but is it worth the expense and weight?  The droop tips are heavy - The Hoerner tips are lighter.

      EDMO

  6. EDMO


    If you look at how many seat trusses have folded up on Avids and Kitfoxes, using the factory bungee gear, you know it's a weak area.  At that point, it's asking for trouble if you don't beef it up.  Even Avid eventually recommended infilling with plywood.   As far as widening the fuselage at the doors, Lots have done that before me as well, Murhel  Williams comes to mind.  He sells a kit/add on you can do yourself.  And in the end, I'm the one taking the most risk.   JImChuk

    Totally agree Jim - "it's MY ass"!  Not all of us are Aeronautical Engineers, or even Engineers, but most have enough common sense to see that something could be made stronger when it has failed so many times before. 

    On the more professional side, as an AMT/A&P, just look at how many ADs, STCs and changes have been made to factory and experimental planes.  If there was no dream or scheme, then how would the Stits Playmate have ever become the Van's RV - How would Avid become Kitfox and so many others that have been modified?  How would John Larsen ever made the Pursang and Airdale which brought the Fat Avids, Avid+, etc, and started the idea of me trying to put separate flaps and ailerons on my bird?  Keep on changing, IMO. 

    I am sure that Budd Davidson had some valid points, although I wrote this without reading his article, but after reading what Jim Chuk wrote - Got to be honest in writing this.  EDMO

    4 people like this
  7. 1avidflyer


    If you look at how many seat trusses have folded up on Avids and Kitfoxes, using the factory bungee gear, you know it's a weak area.  At that point, it's asking for trouble if you don't beef it up.  Even Avid eventually recommended infilling with plywood.   As far as widening the fuselage at the doors, Lots have done that before me as well, Murhel  Williams comes to mind.  He sells a kit/add on you can do yourself.  And in the end, I'm the one taking the most risk.   JImChuk

    2 people like this
  8. EDMO


    Some people use STOL for anything they want to sell - Some use it for undercambered wings - Avid used it for the .065 spars with 15/16" rib spacing compared to the HH with .083 and 12" - The HH could also be considered as a STOL by someone selling a plane, but not by Avid standards.  Check it closely - could also be a 1200 GW, but what difference does 50 lbs make?  These birds are built somewhere around 150% of GW for safety reasons. 

    As Leni said, "If you are in rough air, throttle back and slow down" - If you want to go into physics, then a heavier bird will take more turbulence than a light one - I know that don't make sense to the average person, but it has been shown to be true by those who can explain it better than me.  It has more to do with how fast the bird goes up and down in rough air.   EDMO

    1 person likes this
  9. 1avidflyer


    What are the things to look for? How do I tell if it's a MKIV vs others?

     

     

    This should help...

     

     

    Theoretically MkIV's came into effect at kit ser # 1000 BUT it was

    more like 1100---have the details somewhere.

    Anyway....some work for you ---tee hee heee.

    Does it have the Taildragger gear legs with the step?

    Does it have a 1/1/2" Tailspring necked down to take a MAULE Tailwheel?

    Does it have Elevator with inset trim Tab?

    Does it have Round Rudder?

    Does it have Dorsal steel stringer---i.e Fin tube goes to the T'Deck

    FIN NOT OFFSET

    Does it have a baggage locker?

    Does it have Gas strut fixings just behind left shoulder in fuse frame?

    Does it have Triangular steel welded gussets in EACH corner of the

    "quarterlight window" one gusset is Seat Belt Anchor point.

    Does it have Fiberglass seat?

    Does it have Spring Loaded Door latches?

    Does it have Gusset from Top rear carry thru tube, L&R, outside the

    fuse side frame, welded to the rear Spar Bolt attach bushing---a bit

    like a shelf bracket.

    Does it have two Strap like Plates welded on Rear Wing Carry thru tube

    to inside of rear door post?

    Are ends of Wing Carry thru tubes welded closed?

    Does it have two plates for Fuel Tap behind Vernier Throttle mounting

    plate?

    Are there "glue plates" welded at rear of fuse where inspection plate

    could be fitted for theelevator Push Pull Tube Clevis Fork end they

    Go from Fuse to Fin Spar.

    Are fuselage tubes at this point sort of splayed /opened out for

    greater Bolt clearance?

    There are a couple of other subtle points that can't be checked unless

    tubes cut -- as Avid upgraded some Tube wall thicknesses to get Gross

    up to 1150/1200lbs.

    BUT These should keep you busy for a short while---

    and Send everybody with a "MKIV" running to check!!! heee heee..

    Have fun,

    Regards,

    Steve at Airdale...

     

     

    Also...

     

     

    Looking at our log book (Airdale's) it shows your SN 1388C as

    a C Model STOL TD. The serial numbers before, back to about SN 1025 are listed

    as MKIVs but with a D after the number (as your's has a C). The serial numbers

    after yours are also listed as D's with the designation of MkIV etc. Hope this

    doesn't muddy the water more.

    Jerry at Airdale

     

    Interesting comment by Jerry at Airdale, about # 1388C as the serial # on a C model plane.  I didn't realize they used other letters besides the D after the MK IV serial #.   Other good info about how to tell if it's a MK IV as well.  JImChuk

  10. akflyer


    I see the baggage door behind the seat.  I think I counted enough ribs to make it a HH but not sure, the eyes are crappy and my glasses are at home :lol:

    If the turbulence gets too bad pull the power back and slow her down a bit. 

    :BC:

     

  11. akflyer


    When a known failure point is under my ass you can bet I am going to beef it up.  These planes have evolved over the years and yes, one must think about the affects of changes to other areas of the structures.  We are in the world of experimentals and as such, we get to play around in areas that certified guys don't without tons of paperwork etc.  Lots of people build boats who are not marine architects etc.  

    :BC:

     

    1 person likes this
  12. flywise


    Hi guys,

    I have always wondered how some very talented builders are able to modify primary structures in our light aircrafts....are you all high end aircraft structure designers/engineers??? Have you inputs from Dean Wilson?I have read a good article about this very subject and I would like to have your appreciated comments...

    Everyone who is considering a "beefing up" should read this I believe...

    Cheeers, Laurent

    P.s I would like to ad that this post has absolutely no intention criticizing anyone doing modifications on their birds. I am only trying to figure out if there is / are good ways & tricks to stay safe doing it. 

     

    page1.jpeg

    page2.jpeg

    page3.jpeg

  13. Dusty


    I see this aircraft listed as a STOL,so assuming 1150 pound ?it should have storage behind the seat?

    there are some images online (ZK JFR)if that is any help.

    max weight is a consideration as we usually  fly heavy and can have some savage turbulence (no one likes g meters here :bugeyes:)

    i hope hope to get a look later this week.

  14. dholly


    I assume Brett's poly tanks are unavailable, even though www.wingtanks.com is still up. Kinda like his Airdale website, probably left them up with ads to generate a few click-bait pennies. Some folks here retrofitted poly tanks from Stace Schrader at Rocky Mountain Wings (Ridge Runner kits) for their under camber Avid wings, not sure if those would fit the newer laminar profile KF4-7 wing but I suspect so. There is a notable difference for install however, being that the original KF wingtanks did not employ the Avid style installation with fiberglass wrap totally around the spars and tanks. Cutting the tops off and dropping a poly tank inside is not really an option with the original KF slip-in wingtanks, IMHO. If you opt to replace the KF wingtanks with the RR poly tanks, at the very least you will need to add a new short rib between the tanks (assuming you want two 5-gal tanks in a wing). I would also add a ply bottom between the butt-2 ribs and 2-3 ribs, Hysol'd to the underside of the lower capstrips (or maybe better yet to blocks Hysol'd to the rib webs) before setting, gluing and foaming the tanks in place. Should support the weight of a filled tank and provide much needed structural strength.

    [edit] I would add that the install photos on wingtanks.com also show support tubes between ribs, not convinced they are critical.

  15. dholly


    New student pilot training in an E-AB taildragger WILL be very costly from an insurance viewpoint. Maybe even impossible, as the aviation insurance co's only agree from time to time when they need to add risk to their insured pools to meet required minimums.  The ins. co. WILL require your instructor to have hours in type (10hrs min. in my case, IIRC). I succeeded with a KF3 TD , and then also got reasonable ins. for a KF4 TD before a CFI w/ 10,000hrs bent my Grove gear... which came out of my pocket after the CFI suddenly disappeared. Both EAA and NAFI provide flight insurance to CFI's training in experimental aircraft, I believe that includes their own as well as your aircraft. I recommend you ask if they provide their own ins. that takes precedence over your owner policy in the event of damage when they are PIC. Like many auto ins. co's, one aviation claim can follow you for years and cause higher premiums.

  16. dholly


    Ed, I'm not 100% sure off hand. I think any old paint is ok if you prime plastic first. Not sure if sanding a bit of tooth is absolutely required though, the adhesion promoting spray primers avoid having to do that, i.e. self etching like you used. I have also seen rattle cans from Krylon and (ironically) Rustoleum that specifically say 'for plastics', so maybe you can use these directly without sanding or priming first. Of course the concern with sanding first is that it might be seen through the plastic when viewed from behind on clear sheet. Then again, maybe that would provide a desireable matt vs. gloss effect? Best to test on scrap first to see which paint/procedure provides the look you like.

    One thing for sure, cleaning the Lexan will be critical. Never use ammonia based cleaners like 409 and Windex on polycarbonate, mild dish soap with warm water only. Cleaner/Polisher works on Plexiglass but not Lexan, so to make sure all surface contaminants were removed I would follow with a wiping of isopropyl alcohol, naphtha or mineral spirits only, taking care to avoid the edge face. Any other solvent will cloud or craze the poly. Then another immediate wash with mild dish soap and fresh warm water rinse. Dry with chamois or other clean non abrasive cloth.

    I've never done this little trick on doors personally, but liked what I saw (might have been pics on TKF forum). Looked very clean with that sharp outline and completely eliminates that unsightly dirt and crud catch all between the window and tubing. That is a pet peeve of mine, no matter what I tried I couldn't get my KF doors totally clean and it really sticks out with the white door frames.

  17. nlappos


    A big factor is the useful load, which is of course the difference between the empty weight and the max gross weight. Many car engine Avids have very high empty weight, which limits the useful load. For a typical C model with a 2 stroke Rotax 582,  the useful load might be about 450 to 480 lbs, for a Mark 4 it might be around 580 to 600 lbs. That means two 180 pounders and lots of gas is permitted. There are some auto engined Avids with 350 lbs useful load or even less, which makes it practically a one person airplane..

  18. Av8r3400


    They are very tight lipped on the details of testing and R&D.

    The STi wing is the same span, a very slight increase in chord and quite a bit thicker than the standard Riblett profile. 

    I seem to remember someone saying this was another Ribblett design, but I can't say that for sure. 

  19. SuberAvid


    Did you all notice that the new KF STOL wing has squared off wingtips with fences plus mid wing fences?  It doesn't took like they lengthened the wings, just increased the chord.  I wonder if they did much performance testing of the wingtips to decide the best for short field performance since KF has used drooped tips and Horner style tips before.  Anyone have insight on this?

  20. AFlyer


    Thanks a lot, Jim. I guess I will have to hold on to it for a while before I can get that price. :) I will check on the serial number with the seller.

  21. 1avidflyer


    Hi Adam,  you can send the pics to me in a private email, and I'll give you my opinion.   That and 75 cents will get you a senior coffee at McDonalds.  :lmao:  Do you have the engine serial # as well?  JImChuk

  22. EDMO


    Haha, Joey beat me to it. If you go this route, another neat trick is to paint a black edge on the inside of the window face maybe 1" or so in from the frame edge all around under where the frame tubing will mate. Also under the horizontal brace tube. This will literally make the tape disappear, provide a nice sharp outline and eliminate any aesthetic uglies like inadvertent wiggles due to less than straight tape application or other install difficulties. That tape gives you one shot at positioning the plastic, it is very sticky.

    [edit] Or I suppose you could use white paint, dunno if the tape would show thru though.

    Doug,  Is just any rattle-can paint OK for Lexan, or do you use something special for it?  EDMO

    I know that you can buy cans that say "Plastic paint" too.  I painted some shutters with it and probably screwed up by cleaning with alcohol, and then used a self-etching gray primer before using the Plastic paint - Summer sun caused paint to peal in about 3 years.  I probably should not have used the primer? ??? EDMO