Different wings

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Posted

Hello everybody,

The reason for starting this topic is that I just purchased Avid Flyer MkIV. It is supposed to be with Heavy Hauler wing but

the seller said it to have Heavy Hauler's wing length and speedwing wing profile.

Does anybody have any idea where to get e.g. speedwing profile to make comparation since papers that came with the plane don't have such drawings? Suggestions?

Cheers,

Kekkuli

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Posted

Hello everybody,

The reason for starting this topic is that I just purchased Avid Flyer MkIV. It is supposed to be with Heavy Hauler wing but

the seller said it to have Heavy Hauler's wing length and speedwing wing profile.

Does anybody have any idea where to get e.g. speedwing profile to make comparation since papers that came with the plane don't have such drawings? Suggestions?

Cheers,

Kekkuli

The speed wing does not have the undercamber in the wing. If they built it to HH specs (more ribs and heavier spars) then you really have the best of both worlds. The full length speed wing will fly almost as slow as my HH wing. I could get my buddies MK IV with the extended speed wing in and out just as short as my C HH.

Wing contruction.pdf

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Posted

Welcome Kekkuli,

I built a custom hybrid 'long heavy hauler speedwing' for my Avid+, hoping to have the best of both worlds. I used and followed the Mk-IV Heavy Hauler material and construction method (see both Leni's .pdf drawings and the wing difference explanation below), however, I substituted the flat-bottom Speedwing ribs instead of the under-cambered Heavy Hauler/STOL ribs. The root rib on Avid Speedwing/Aerobat planes is a special 'transitional' rib that matches up to the butt rib (which was always HH/STOL shaped to allow folding wing clearance). In the attached pictures, you can clearly see the differences between the speed and under-cambered rib profiles both on and off my wing.

Also keep in mind, 'Heavy Hauler' was the name attached to several Avid models. A Heavy Hauler B or C model was 1050lbs M.T.O.W. A Heavy Hauler MkIV was originally 1150lbs and then, to compete with the Kitfox 1200, "re-marketed" as 1200lbs. This is the reason one has to be careful around Avid gross weights and wings. In addition to wing length, material and construction differences, the under-cambered HH rib profile was very different from the flat-bottomed Speed rib profile.

In general, Avid Flyer wing differences extend to spar thickness, spar length, lift strut o.d. diameter, airfoil, rib spacing and drag tubes. All wings called for (2) nose ribs between wing ribs, though an additional nose rib per bay is often added on the Speed and STOL wings due to their wider rib spacing. Here are the basic differences between the (4) Avid Flyer wings explained:

Speedwing
: .065" thick 2-1/2" o.d. spars; 108-1/2" spar length; 3/4" dia. lift struts; Avid flat bottom airfoil; (7) ribs ~ 18" o.c.; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71" and 106-1/2" o.c. from tip rib

Mk-IV HH
: .083" thick 2-1/2" o.d. spars; 144" spar length; 7/8" dia. lift struts; Avid undercamber airfoil; (13) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib

STOL
: .065" thick 2-1/2" o.d. spars; 144" spar length; 3/4" dia. lift struts; Avid undercamber airfoil; (9) ribs ~ 18" o.c.; (4) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib

Mk-IV Aerobat
: .083" thick 2-1/2" o.d. spars; 108-1/2" spar length; 7/8" dia. lift struts; Avid flat bottom airfoil; (10) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (2) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", and 106-1/2" o.c. from tip rib

* Applies to wings with wire trailing edge only, not required with metal trailing edge.

Be aware that wings with the exact same descriptors, ie., STOL wings, may have different Gross ratings depending on when they were sold/built. One thing is certain, there were so many combination of fuselages and wing components bought, built, or cobbed together over the years it can be very difficult to determine exactly what Gross you have unless you physically measure spar thickness, tubing diameter, or even cut a tube to verify wall thickness.

With the s/n#, Airdale Sportplane and Supply may be able to provide an accurate factory build manifest at the time of sale but, beware, changes could have easily been made in the years following that impact the original Gross.

Hope that helps. Best of luck with your new Avid, let us know how things are going!

-Doug

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Posted

The speed wing does not have the undercamber in the wing. If they built it to HH specs (more ribs and heavier spars) then you really have the best of both worlds. The full length speed wing will fly almost as slow as my HH wing. I could get my buddies MK IV with the extended speed wing in and out just as short as my C HH.

Wow, I just placed the question and there is a reply right a way. Impressive :-)

Thanks for the drawings.

Sorry, my poor skill in english fails me. What is undercamber? Do you mean that if you look wing's undersurface from the base towards the wing end,

the surface twists or is that proper word for that??? So the wing angle of attack changes when walking towards the end of the wing?

What kind of engines do you have in your planes?

About speeds, my plane has Hirth F30 engine that should give around 95 hp...

I had just a very short test flight before buying the plane so I don't have first hand knowledge about stall and slow flight speeds.

The speed on my test ride seemed to settle well over 100 mph IAS at 2000 ft but we were still climbing at that moment. Vne has been set to be 115 mph.

The test pilot who initially flew the plane year 1995 wrote that she was fully control at 36 mph with 10 degree flaps.

What are typical stall and cruise speeds (and Vne) for the plane with HH wing? How about Speedwing?

Kekkuli

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Posted

'Camber' refers to the curve of the lower rib airfoil surface. The flat-bottom speed rib airfoil surface has zero camber. Because the lower rib airfoil surface of the HH/STOL rib curves upwards (towards chord line) it is said to be under-cambered. The 'twist' built into a wing as viewed from root to tip is also called 'washout'.Sorry I can not help with speed comparison yet, still building mine.

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Posted

Basically, really close to a model IV Kitfox wing. They work really well.

:BC:

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Posted

Welcome Kekkuli,

I built a custom hybrid 'long heavy hauler speedwing' for my Avid+, hoping to have the best of both worlds. I used and followed the Mk-IV Heavy Hauler material and construction method (see both Leni's .pdf drawings and the wing difference explanation below), however, I substituted the flat-bottom Speedwing ribs instead of the under-cambered Heavy Hauler/STOL ribs. The root rib on Avid Speedwing/Aerobat planes is a special 'transitional' rib that matches up to the butt rib (which was always HH/STOL shaped to allow folding wing clearance). In the attached pictures, you can clearly see the differences between the speed and under-cambered rib profiles both on and off my wing.

Also keep in mind, 'Heavy Hauler' was the name attached to several Avid models. A Heavy Hauler B or C model was 1050lbs M.T.O.W. A Heavy Hauler MkIV was originally 1150lbs and then, to compete with the Kitfox 1200, "re-marketed" as 1200lbs. This is the reason one has to be careful around Avid gross weights and wings. In addition to wing length, material and construction differences, the under-cambered HH rib profile was very different from the flat-bottomed Speed rib profile.

In general, Avid Flyer wing differences extend to spar thickness, spar length, lift strut o.d. diameter, airfoil, rib spacing and drag tubes. All wings called for (2) nose ribs between wing ribs, though an additional nose rib per bay is often added on the Speed and STOL wings due to their wider rib spacing. Here are the basic differences between the (4) Avid Flyer wings explained:

Speedwing
: .065" thick 2-1/2" o.d. spars; 108-1/2" spar length; 3/4" dia. lift struts; Avid flat bottom airfoil; (7) ribs ~ 18" o.c.; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71" and 106-1/2" o.c. from tip rib

Mk-IV HH
: .083" thick 2-1/2" o.d. spars; 144" spar length; 7/8" dia. lift struts; Avid undercamber airfoil; (13) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (3) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib

STOL
: .065" thick 2-1/2" o.d. spars; 144" spar length; 3/4" dia. lift struts; Avid undercamber airfoil; (9) ribs ~ 18" o.c.; (4) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", 106-1/2" and 142" o.c. from tip rib

Mk-IV Aerobat
: .083" thick 2-1/2" o.d. spars; 108-1/2" spar length; 7/8" dia. lift struts; Avid flat bottom airfoil; (10) ribs ~ 12" o.c.; (1) 1/2" dia. W-2A steel drag tube; (2) 1/2" dia. W-2 alum drag tubes; (3) W-3S Short 5/16" dia. alum root rib brace tubes; (1) W-4 Short 1/2" dia. alum root rib brace tube; (1) W-3L Long 5/16" dia. alum tip rib brace tube*; NOTE: Wing tank replaces (1) W-2A, (3) W-3S and (1) W-4 alum rib brace tubes at the root end of wing; Key rib dimensions (long rib flaperon hinge) are 35-1/2", 71", and 106-1/2" o.c. from tip rib

* Applies to wings with wire trailing edge only, not required with metal trailing edge.

Be aware that wings with the exact same descriptors, ie., STOL wings, may have different Gross ratings depending on when they were sold/built. One thing is certain, there were so many combination of fuselages and wing components bought, built, or cobbed together over the years it can be very difficult to determine exactly what Gross you have unless you physically measure spar thickness, tubing diameter, or even cut a tube to verify wall thickness.

With the s/n#, Airdale Sportplane and Supply may be able to provide an accurate factory build manifest at the time of sale but, beware, changes could have easily been made in the years following that impact the original Gross.

Hope that helps. Best of luck with your new Avid, let us know how things are going!

-Doug

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Posted

I'm looking at an Avid MK4 reported to have a 1550lb gw.

What am I looking at?

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Posted

I'm looking at an Avid MK4 reported to have a 1550lb gw.

What am I looking at?

A liar.... well.. Truth be told yet again, there is no hard and fast gross weight. If the builder did a little beefing up here and there when he built it, and loaded it up to a 2000# gross during phase 1 and documented that, then you could fly it at 2000.. Not saying that is smart or prudent, but that is legal to do. You as the builder set the gross weight. I am not aware of any factory "gross" weights over the 1200 that Doug mentioned.

:BC:

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Posted

gwooley-

I added a comment to your Avid Yahoo Group query and will repeat it here, as several folks have commented without your acknowledgement. A quick courtesy post to let folks know you received and appreciate their input is helpful, and will likely pay dividends the next time you post a question. ;)

Re: gross weights

The rib profile on that Avid looks like Harry Riblett's Kitfox airfoil to me.

You can also see the thicker, symmetrical flaperons consistent with the new

Kitfox wing. That same airfoil was used on Kitfox Models 4-7 w/ 1050lb, 1200lb,

1320lb, 1400lb and 1550lb Gross. Changes in wing, strut and fuselage design and

materials all came into play during the Kitfox evolution and ensuing Gross

Weight increases. It only stands to reason that you can't take the wing off a

1550lb Gross Kitfox 7, bolt it to an Avid Mk-IV Heavy Hauler w/ 1050lb or 1200lb

Gross and magically have a 1550lb Gross Avid MK-IV HH. Gross Weight or M.T.O.W.

would still be determined by the lessor of the two planes limitations. Look at a

naked Avid Mk-IV fuselage and compare to a KF model 6 or 7 fuselage. No argument

which is more substantial. You would need to upgrade front and rear spar carry

through tubes, seat truss, door post and other various fuselage tubing o.d and

wall thickness, landing gear etc., etc. to increase Gross over 1200lb for the

Avid. And, IMHO, I just don't see the possibility of making it all the way to

1550lbs without a darn near whole new fuselage. Sure, a builder can put whatever

he/she wants on the data plate, but I would be -VERY- interested in seeing a

list detailing each and every modification done to this Avid which leads the

builder to claim 1550lb Gross is safe.

--- In avid_flyer@yahoogroups.com, "grwooleysr" <grwooleysr@...> wrote:

>

> I'm looking at an Avid Heavy Hauler MK4 that is reported to have a grw of 1550

lbs. Is what I'm hearing possible?

The removable wing tips look like standard issue KF tips as well, and the fact that the owner is connecting the flaperon control tubes (all KF models from 4-1050 up require disconnecting to fold wings) all pretty much tell the story here. Again, if all the fellow did was attach KF 5-7 wings and struts to a stock Avid Mk-IV, Steve Winder or any of the old Avid factory representatives would tell you the aircraft was still only good for 1200lb M.T.O.W. ...period. Is the wing physically stronger? Sure, but load that Avid to 1550lb then over stress it once and I suspect the wing is not what will fail.

IMHO, the owner/seller is waaay too optimistic on his gross weight claim and, without extensive build modification and flight testing documentation, is setting himself up for a hell of a liability suit. You did right to question it. As always, caveat emptor.

:2cent:

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Posted

I know this guy...those wings are from a Kitfox 6.

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Posted

I wouldn't swear to it, but I seem to remember that the later Kitfoxes use .065" wall thickness spars even in their 1500 GW planes. If that is the case, the Avid HH wing with .083" spars should be a good bit stronger I would think. Then again, a chain is only as strong as it's weakest link, so it doesn't matter if the wing can take it, but the carry through or the struts or some other part fails , you are still in trouble. Jim Chuk

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Posted

From what I remember from the Magnum builder's manual - The HH wing looks the same as the Magnum.

As far as I know, Kitfox continued to use the .065 spar when Avid went to the .083.

When the supply of Kitfox spars with the vertical web ran out, they went to the Avid-type instert.

Don't know if Avid ever had the vertical-web spars.

Again, being involved with this design since about 1995, I totally agree with the others that the wing does not totally determine a SAFE gross weight - The fuselage and struts have a large part in determining the GW, and don't forget the landing gear too.

Doug, as always, you come thru with some great technical information.

EDMO

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Posted (edited)

my wing spars are .83 and has HH ribs and total wing is 12 ft. and have 10 ribs with 2 false ribs and has alum raps about 12 in.   HH wings are supposed to be 14ft.  has anyone have any experience with this set up?  thanks Randy in tn. also  looking for someone close to dyersburg tn with experience with the avid .cell 731 589 1330   email no1son38@aol.com

Edited by no1son38

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Posted

I have STOL wings with .083 spars and 7/8" lift struts.

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Posted

Wow, this thread has had over 9.3 MILLION views?  You guys are rock stars!

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Posted

I didn't think that Google would land that many hits without some sort of wierd porn being involved...

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Posted

That's why te forum took a dump a few weeks back. Doug I'm going to move the wing info into the files and forms area. Sure there's lots of folks who have needed access to that data at some point.

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Posted

Doesn't Just Aircraft claim up to 1500 lbs on their aircraft, they were using a .063 or .065 spar in their aircraft. Dean Wilson knows how to design an airplane, they were originally tested to a load way over the gross weight, but there is a difference between Flying and where you land, as has been stated before it is more than just the wing that makes a plane capable of handling higher loads. There has become a lot of stories on this design and some truths that have become facts, I would love to spend a day talking with the man, and I wonder if He knew the plane he designed 30 years ago would still be a major factor in aircraft today.

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Posted

Kitfox does 1550 gross with .065" spars and the same 60" long "I" beam insert as the rest of their planes. It's a landing gear change to increase the gross.

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Posted

Kitfox only went to the insert after the integral I-beam spars were gone. I wonder if a comparison bending analysis was ever done.

Someone said or wrote that Dean flew the early Avid .065 spars at 1500 gw - was this without inserts?

EDMO

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Posted

I don't know about any further analysis, but that is the system in use from the IV through the current SS.

Avid used a plywood insert.

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Posted

are your spars 12' plus the wing tips? this is normal or is your complete wing root to tip 12' sounds like you may be missing one complete wing bay. might be possible that the builder had aerobat spars and built them with HH ribs not sure why you would want to shorten up the HH wing though. are you sure you don't have flat bottom speed ribs in which case you have an aerobat wing :)  (alum raps about 12") I'm not sure I follow this do you mean that the leading edge is wrapped in alum? I'm sure someone else more knowledgeable than I will help you on this matter. good luck

 

-Robert-

my wing spars are .83 and has HH ribs and total wing is 12 ft. and have 10 ribs with 2 false ribs and has alum raps about 12 in.   HH wings are supposed to be 14ft.  has anyone have any experience with this set up?  thanks Randy in tn. also  looking for someone close to dyersburg tn with experience with the avid .cell 731 589 1330   email no1son38@aol.com

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Posted

'Camber' refers to the curve of the lower rib airfoil surface. The flat-bottom speed rib airfoil surface has zero camber. Because the lower rib airfoil surface of the HH/STOL rib curves upwards (towards chord line) it is said to be under-cambered. The 'twist' built into a wing as viewed from root to tip is also called 'washout'.Sorry I can not help with speed comparison yet, still building mine.

Doug,

As the guru of wing info - Is the Avid speedwing rib the same on bottom as the Riblett Kitfox ribs, or is it flatter?

EDMO

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Posted

Doug,

As the guru of wing info - Is the Avid speedwing rib the same on bottom as the Riblett Kitfox ribs, or is it flatter?

EDMO

 

Ed - Avid rib is the one with oval web cutouts.

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