AVID SPAR QUESTION

[EDMO 1078]

Someone stated that Dean Wilson flew one of the early Avids at about 1500 gw -My question is - With what spar, and what strut?

Also, did Avid use the spars with the extruded vertical web in the early ones, or was that strictly a Kitfox spar?

EDMO

[dholly 718]

To the best of my knowledge Avid only used extruded spar stiffeners in the Magnum spar.

[akflyer 1427]

The construction manuals I have for the A through the MK IV all show the wood stiffeners.  Struts and spars are per the Stol, HH or speed wing from what I can tell.  There is kind of a mixture scattered around too where some kits were shipped with the heavier spars even though they were the lighter gross weight planes.  I think it was a supply issue and kits were shipped with stock on hand some times.

 

[EDMO 1078]

To the best of my knowledge Avid only used extruded spar stiffeners in the Magnum spar.

Doug, I have no knowledge of that - My Magnum manual has builder-fabricated stiffeners.

I was wondering if any of the very early Avids had the full-length extruded web in the tube like the early Kitfoxes. Kitfox went to builder-made inserts, and then a factory-supplied extruded insert after the supply of original tubes with the full length web ran out. I keep wondering which spar would be stronger, but not about to damage tubes in testing to find out.

EDMO

Edited 6 Jul 2013 by Ed In Missouri

[dholly 718]

Avid A-4 never used a spar with full length stiffener, extruded, inserted or otherwise. The early Avid Magnum design at 1500lbs. gross, used identical 0.83" spars and ribs as Mk-4 HH, but added 1" x .049 wall 4130 lift struts, steel drag tubes (vs. aluminum) and 1/4" x 24" long ply stiffeners. Shortly afterward, Magnum gwt was increased to 1650lbs. with the addition of 1/8" x 24" aluminum stiffeners similar in shape/size as the original plywood type, however, two strips of 1/8" x 1/2" aluminum were riveted along the top edge of the aluminum stiffener to form a kind of 'T-Beam'. All other wing components being equal, the 2nd stiffener was good for a 150lb. (10%) gwt. increase. Even later, gwt was raised to 1750lbs. with the addition of a 36" extruded aluminum 'I-Beam' style stiffener.

[EDMO 1078]

Thanks for the Magnum info Doug. I guess Kitfox still uses the factory extruded I-beam stiffener that replaced the builder-produced stiffener that replaced the full web?

EDMO

Edited 6 Jul 2013 by Ed In Missouri

[dholly 718]

Thanks for the Magnum info Doug. I guess Kitfox still uses the factory extruded I-beam stiffener that replaced the builder-produced stiffener that replaced the full web?EDMO

No need to guess. Kitfox site description includes "6061-T6 Aluminum Extruded Spar Stiffeners".

Go to Tom Waid's excellent Kitfox SS builder website for assembly pics: http://tropicaltuba.com/Kitfox%20Project/Kitfox.htm

[akflyer 1427]

does anyone know where I can get the spar material other than from KF   I need the .083" thickness.  It is time to build a set of long KF IV wings to the HH specs for the ole avid and see how they do for me.

 

Shipping up here kills us, but I have a guy headed this way in late september / early october that will haul up enough for bob and myself to build wings.

 

[Av8r3400 1179]

My friend Dave (the hybrid builder) bought his spar tubing from a local steel/aluminum supplier.  It's nothing special.

 

He bought the extruded "I" beams from Kitfox.

[akflyer 1427]

Larry,

 

I have the two local distrubutors looking for it and they can find the .065 all day long, but not the .083.  If you can get me the number to the place he bought it from that would be awesome!  Two years ago, my local place could find the .083 everywhere, but now it seems to be a bit of a shortage on it as no place on the net I have found has it.  I can get .065 or .125, but not .083....

 

[Av8r3400 1179]

He used .065".  This is because he used the Kitfox extruded stiffeners.  They require that size.  I do remember he had to buy four 24' lengths.  This tubing was available in 12' or 24' lengths.  In retrospect he would have used the 12' pieces and went with a shorter wing.  He sold the drops to Brett to make wing extension kits with.

 

Remember, with a 60" stiffener Kitfox rated this wing up to 1550 gross weight.

 

The local place is:

 

Londerville Steel & Concrete Supplies

[EDMO 1078]

Leni,

Get on the phone to Anchorage - Now I guess I am senile - would have to check my papers to find the name of the biggest steel AND aluminum supplier there - Oh yeh - ALASKA STEEL - Check the wall thickness for schedule 10 or 20 aluminum seamless pipe - it is 6061, and I think up to 20 foot.

Also, check on aluminum tubing. They have a "bone-yard" where you may find a bargain, but you have to go there and look.

There was a fairly new pipe company there also when I left - We bought our stainless pipe/tube from them - Cant remember the name tho.

EDMO

Edited 7 Jul 2013 by Ed In Missouri

[akflyer 1427]

Leni,

Get on the phone to Anchorage - Now I guess I am senile - would have to check my papers to find the name of the biggest steel AND aluminum supplier there - Oh yeh - ALASKA STEEL - Check the wall thickness for schedule 10 or 20 aluminum seamless pipe - it is 6061, and I think up to 20 foot.

Also, check on aluminum tubing. They have a "bone-yard" where you may find a bargain, but you have to go there and look.

There was a fairly new pipe company there also when I left - We bought our stainless pipe/tube from them - Cant remember the name tho.

EDMO

Been there done that.  Sch 5 pipe is .125"  no good.  I have been blowing up AK steels phone for 3 weeks trying to get them to find the .085" stuff for me.  They dont have 160' of the stuff in the bone yard

 

I need enough for a set of wings for myself and a set for Bob.

 

[EDMO 1078]

Been there done that.  Sch 5 pipe is .125"  no good.  I have been blowing up AK steels phone for 3 weeks trying to get them to find the .085" stuff for me.  They dont have 160' of the stuff in the bone yard

 

I need enough for a set of wings for myself and a set for Bob.

 

Did you find the pipe and tubing supply company in Anchorage? They were a huge new outfit when I was there - think they got the piping contract for one of the big platforms to be built there. What rib are you going to use?

ED

Edited 7 Jul 2013 by Ed In Missouri

[akflyer 1427]

Did you find the pipe and tubing supply company in Anchorage? They were a huge new outfit when I was there - think they got the piping contract for one of the big platforms to be built there. What rib are you going to use?

ED

Going to use the KF IV ribs and only put .500" wash out in them.  May even extend them another bay and put square board tips on it (the boards extend about 2" all the way around the rib profile.  May even put some fences on the top side.  I even thought about modding them for conventional flaps and ailerons.  Will see how ambitious I get when the parts get here

 

I even thought about going with a tcrate airfoil.... Not sure what kind of frankenplane I will end up with, but I want more wing and better cruise.  It only took one 90 degree day on floats for me to decide I want more wing!  The new engine will take care of the take off and climb, but hot days and engine outs SUCK!  I rode in a Pacer on floats after and engine out and the Avid is much the same in that respect.  On floats I have the glide ratio of a streamlined anvil! 

 

[EDMO 1078]

As soon as I get this 2nd leading edge finished, I am ordering enough 36" ribcaps and new trailing edge to do all of my ribs and get rid of the undercamber, per my mod of the Riblett drawing.

I don't need undercamber with the flaps. I extended 4" and will lose about 1 1/2 or 2" at rear.

EDMO

[EDMO 1078]

Going to use the KF IV ribs and only put .500" wash out in them.  May even extend them another bay and put square board tips on it (the boards extend about 2" all the way around the rib profile.  May even put some fences on the top side.  I even thought about modding them for conventional flaps and ailerons.  Will see how ambitious I get when the parts get here

 

I even thought about going with a tcrate airfoil.... Not sure what kind of frankenplane I will end up with, but I want more wing and better cruise.  It only took one 90 degree day on floats for me to decide I want more wing!  The new engine will take care of the take off and climb, but hot days and engine outs SUCK!  I rode in a Pacer on floats after and engine out and the Avid is much the same in that respect.  On floats I have the glide ratio of a streamlined anvil! 

 

If you plan on doing it the hard way (my way) it will take all new flap and aileron hangers and bushings, and completely different controls. Ailerons should be 8 to 10% of wing surface, (10% is better) or about 7 square feet - mine are 6 feet long and 14 to 15 inches wide - flaps are same width and 6 1/2 feet long.

EDMO

[Av8r3400 1179]

If it ain't broke don't fix it.  

 

Flapperons work great, offer superior roll control well into the stall and don't require all kinds of hidden rigging inside the wing.

[EDMO 1078]

If it ain't broke don't fix it.  

 

Flapperons work great, offer superior roll control well into the stall and don't require all kinds of hidden rigging inside the wing.

Don't see how they can compare with flaps and ailerons for roll control in crosswinds - Steve Wittman designed his with controls similar to the Avid - that is my intention too.

EDMO

Edited 8 Jul 2013 by Ed In Missouri

[Av8r3400 1179]

I've flown mine in some pretty good gusting cross winds without problems.  It's not a 182 or a King Air.  I don't expect that type of performance nor do I want it.  I fly my plane for enjoyment, not as an exercise in extreme weather flying.  It's a 650 pound tail dragging, toy.  

 

IMO, you are going through a ton of trouble to fix a non-problem with a great design for it's mission.  (Hence, If it ain't broke don't fix it.)

[EDMO 1078]

Anytime two controls are combined, each control gives up some of its efficiency - When flaperons are used for flaps, you will lose some aileron effectiveness, and some roll control. I learned a lot about the downside of combined controls while flying the Ercoupe.

I have flown both types, and like flaps and ailerons better than flaperons.

I am just building my "experimental" plane the way I want it built. Since mine is not "Kit-built",I would have to build flaperons or flaps and ailerons anyway, so why not go with what I like best.

EDMO

Edited 8 Jul 2013 by Ed In Missouri

[akflyer 1427]

I would love to be able to use MORE flap yet still have the ailerons available for full roll control (as in not getting into control reversal)  as well as a fewother bennys of separates.  It is not that the design is "broke", but if it can be improved upon for my particular use, then while I am building a new wing, why not incorporate some relatively easy mods?  I was thinking about installing a turbine, 3 axes auto pilot, 200 HP turbine and a shitter while I was at it

 

:bc:

[EDMO 1078]

I would love to be able to use MORE flap yet still have the ailerons available for full roll control (as in not getting into control reversal)  as well as a fewother bennys of separates.  It is not that the design is "broke", but if it can be improved upon for my particular use, then while I am building a new wing, why not incorporate some relatively easy mods?  I was thinking about installing a turbine, 3 axes auto pilot, 200 HP turbine and a shitter while I was at it

 

:BC:

Be sure and talk to SuberAvid, and decide if machine guns or bazookas would be better than the wing-mounted shotguns!

ED

[akflyer 1427]

Be sure and talk to SuberAvid, and decide if machine guns or bazookas would be better than the wing-mounted shotguns!

ED

I figured a mini gun on one side would take care the birds in the flight path and howitzer would take care of the nusance bears..

[EDMO 1078]

I figured a mini gun on one side would take care the birds in the flight path and howitzer would take care of the nusance bears..

Flare guns would be nice too - maybe for the 4th...Just don't outrun the flare, like some of our early jet fighters caught up with their own fired bullets.....

ED

Edited 8 Jul 2013 by Ed In Missouri