Thursday, December 29, 2011

Top 12 Things you can see in test flight video of ultralight aircraft

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

Here is what you'll see, in this YouTube video of Belite's ultralight airplane:

10.  I turn to the camera and smile a lot.

9.  I do mild wingovers.

8.  I do steep turns around a point.

7.  I enjoy the beautiful weather on December 29, 2011.

6.  I get to prove that flying is more fun than working.

5.  I make the owner of this airplane wonder why I haven't delivered it already.

4.  I do a really sweet full stall 3 point landing.  If you look very, very carefully, you can see the steel landing gear springs barely compress, but just for a moment.

3.  You can see what a poor video editor I am.  Actually, I didn't do any editing ... just loaded the video to YouTube.

2.  At the end, you can see Mike, Gene, and my nephew, Matt.

1.  You can see the plane climb from ground level to 800' AGL in a little over two miles of ground distance.

0.  You can see me dive the plane to over 80 mph (IAS)

-1.  You can see why I enjoy doing this.

Sunday, December 25, 2011

Streamlined Struts produce zippy performance!

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Merry Christmas!!

One quick post on one of our development items, along with a new Belite video on YouTube --

I'll skip the analysis and just talk about the results --

After installing streamlined lift strut fairings on an airplane, I believe that we reduced drag at cruise speed by about 18 pounds.   This increases cruising speed, with our smallest engine, by about 5 mph.  That is very significant when we are talking about cruising speeds in the 50's with just a 28HP engine.

I borrowed Eric's plane for the installation and test of the new lift struts.  The proof is in pictures and video.  It's just a couple of minutes long, please watch this video!

Remember, I weighed 210+ pounds and the performance was just awesome.  The plane was also configured with our new improved flaperons.

We've also upgraded to a new HD camera for our inflight videos.  Just got it a couple of weks ago.  I learned a lot about how to mount cameras on aircraft when I was working at Mythbusters on the Duct Tape Plane myth., and you'll see much more airborne ultralight HD video in 2012.

James Wiebe, EAA 2011 August Raspet award winner

Wednesday, December 21, 2011

More on "Hoerner Wingtips" in ultralight aircraft

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

My previous post cited the work of Dr. Hoerner in the development of wingtips which produce smaller vortices, which consequently produces less drag, which consequently allows more speed (for a given thrust), and consequently a better rate of climb....

Clearly the Hoerner wingtips are a desirable thing.  While there are other ways to produce effective vortice reduction (for instance, vertical winglets or even flat plates), the Hoerner wingtip is more easily fabricated, and frankly, in my opinion, just looks darn sexy.

Soooo, it's worthwhile to spend a couple of minutes reviewing Dr. Hoerner's research, so we can guess what positive results these wingtips will give us.

Below is a basic illustration of a wingtip vortice, which I have copied from Dr. Hoerner's most excellent book, "Fluid Dynamic Drag".

Vortice at wingtip, from Fluid Dynamic Drag, by Hoerner
This illustration shows how high pressure air is spilling from the underside of the wing out of the wingtip, causing the vortice.  (The villain isn't the vortice, it is the fact that a vortice is created by the loss of high energy air from the bottom of the wing.  The evidence and creation of a vortice only proves the problem.)

Dr. Hoerner reviewed several different kinds of wingtip configurations, including square wings with sharp edges (which is exactly what our Belite ultralight airplane has), along with round rectangular edges, sharp rounded wings, sharp full wings, and more.  He also reviewed vortices and drag  reduction around wingtip fuel tanks (which are not in our current Belite innovation plans.)   With each kind of wingtip shape, he calculated and presented the effective span of the wing -- in other words, a longer wing is a better thing -- and if you get that length 'for free' (by using better wingtips), that is a really good thing.

The very worst wingtip is a rounded wingtip, with a round cross section.  The very best wingtips are ones which have a sharp cross section.

And interestingly, the square wingtip with a square edge is nearly as good as the very best wingtip, but not quite.  It is worthwhile to quote Dr. Hoerner on this topic:

"Theory predicts minimum induced drag for elliptical lift distribution across the span....   however, directly in one case... that a rectangular wing (with sharp lateral edges) does not have a higher drag due to lift than the elliptical wing."

Wow.  Score one for Belite, and the game of innovative improvement hasn't even started!

Back to Dr. Hoerner's writing:

"It is seen that the most effective plan forms are the rectangular, the moderately tapered ones and those which have a long trailing edge....   In other words, to make the span of the rolled-up vortex system, or the effective span of a wing of given basic shape, as wide as possible, it is favorable to keep the tip vortices apart from each other as far downstream as possible."

Now if I look back at his charts, I do see that sharp wingtips have an advantage over the square wingtip with square edges, and all of those have huge advantages over rounded  wingtips.

So the Hoerner wingtip is taking it to the next level.

Let's find some more interesting remarks from my new best friend, Dr. Hoerner.  He makes some comments about the most ideal wingtip shape, which I (and others) now call "Hoerner wingtips":

"In case of [Hoerner wingtips], which is the most favorable one concerning small drag due to lift as well as to minimum sectional drag, it appears that one additional effect is the bent-up shape.  Experimental data.... on a small-aspect-ratio wing, confirm that this feature is important.  Combination of [Hoerner wingtips] with a moderately tapered plan form is believed to be the most effective..."

So things get a bit 'guess-work-eee' from here.  But we think that we know the following:

 * sharp wingtips reduce the size of the vortice -- which is what the Hoerner wingtip is all about
 * the addition of the Hoerner wingtip spreads the trailing edge, adding span, and further separating the vortice
 * sharp wingtips have less drag at higher angles of attack, which is where ultralights spend more time at than higher speed airplanes

Hey, wait a minute.  I better provide some documentation for a couple of those points.  Here's another illustration from the book which helps:

Improvement shown with Hoerner wingtips -- with square wingtips not far behind!
The illustration shows, on the top right hand side of the curve, the slightly higher coefficient of lift achieved with the Hoerner wingtips.  Square (Belite) wings are close behind, with round wings falling off considerably.

Here's a final helpful illustration, showing the cross section of vortices with sharp vs round wingtips:

Decreased vortice size with Hoerner wingtips (a) vs round (b) or wingtip tanks (c)

Finally, some conclusions...

Q.  So what is all of this worth to a Belite ultralight aircraft?

A.  We believe the aerodynamic effective span will increase by a little over 2 feet.  However, we are cheating a bit, because the Hoerner wingtips will add about 20 inches of real span all by themselves.  The increase in effective wing area is 7+ square feet!  (with an original wing area of about 108 square feet).

Q.  What performance increases will result?

A.  Hopefully I'll see an improvement in climb rate, a reduction in stall speed, a reduction in takeoff roll, a reduction in landing roll (I'd like to beat my personal measured 100.5' landing record -- which I know I'll be able to do [because I've already done it in another Belite, before I even started talking about Hoerner wingtips   :-)  ])  and more...

Q.  What weight penalty do the wingtips entail?

A.  Substantially less than a 8 ounces per wing, vs. our existing square design.   Really!

Q.  What if they don't work quite that well?

A.  Then I'll get to figure out why, and I'll have the coolest looking ultralight airplane on the planet.

My thanks to Dr. Hoerner, and his wonderful book.  I believe my quotes and illustrations taken from his book fall under fair use doctrine.

I am also indebted to Mike, who is building this wonderful test airplane with Hoerner wingtips for me.

If you want an overview of what else I'm working on (and willing to talk about) you can read it here:

Upcoming 2012 Product Innovations at Belite Aircraft

-- James Wiebe, 2011 EAA August Raspet award recipient

Monday, December 19, 2011

Upcoming 2012 Product Innovations at Belite

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

"Upcoming 2012 Product Innovations at Belite"

 an overview of what's coming...
 this post focuses on "Hoerner Wingtips"

One of the absolute joys of my pseudo-job is that I get to investigate, implement and test aerodynamic improvements to my Belite ultalight airplanes.  As a result, I have come up with a goal of decreasing drag on our aircraft so that our very smallest engine option will allow cruising flight at 62mph.  (And the larger engines will require throttle limitations in order to stay within Part 103 -- or registration as experimental aircraft.)

When all is implemented, this will provide important improvements to takeoff and landing performance, along with substantial improvements to climb rate, reduced stall speeds.

Because our aircraft is so similar to a conventional high wing aircraft, I have identified several opportunities for drag reduction which are already available on many 'commercial' certified aircraft.  These opportunities include:

a)  lift strut drag reduction via fairings  --  all airplanes should have this
b)  wingtip drag reduction via reduction of wingtip vortices
c)  increased Lift / Drag in wing airfoil via subtle improvements
d)  reduced drag due to improved cowling design
e)  And maybe there will be more.

(none of these future options have been made available, or even priced yet)

I've already implemented and test flown a Belite with lift strut fairings, and I will provide a full report soon.  Hint at the outcome:  It was awesome.

I'm also working on a changed cowling design -- it will take a few more months and I'll have that one ready for report.

I've been reading through a variety of aerospace engineering reports on wing airfoils.  I find that my engineering and math background are an excellent helper for me as I've learned more and more about airfoils.

As for wingtip vortices, lots of people already know that Dr. Hoerner tested many different types of wingtips, in order to select and document those which increased effective span and reduced drag by reducing or eliminating those nasty wingtip vortices.  I happen to have gotten my hands on a copy of a couple of his books (they were loaned to me by a friend at my Church) and they have been delicious reading for my ultralight aircraft aerodynamic engineering education.

So, here's some photos of a set of wings in construction progress, showing Hoerner wingtips being fabricated.  These will end up on a plane which is being built to exhibit at Sun N Fun in 2012.  No opportunity for improvement is being overlooked in this airplane.  The wings in question are carbon fiber spars, with aluminum ribs, and the Hoerner wingtips.  You may also notice that they are also being prepared for VFR night flight via the addition of wingtip lights.  (The airplane is being built with a heavy 4 stroke engine, and will be registered experimental, thus allowing night flight.  It will be also be flyable as a legal FAR Part 103 airplane, albeit with a different engine.).  (This particular set of wings is being built by builder Mike.  Mike is awesome.)

So here are the pictures:

Belite Ultralight Aircraft wing, under construction with Hoerner wingtip

Detail of Hoerner wingtip, showing nav light fairing

Front view of Hoerner wingtip, with much smooth work still to do

Quartering view of Hoerner wingtip

View of Hoerner wingtip, prior to adding foam to front cell

Trailing edge quartering view of Hoerner wingtip

View of Hoerner wingtip from outside rear

Friday, December 9, 2011

Belite's Turn Coordinator: "More sensitive and more stable..."

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

From one of our customers, we received this unsolicited testimonial concerning our Turn Coordinator and VSI:

Attached are two snapshots of my instrument panel "upgrade". The close-up shows the turn coordinator and the VSI (with an aux power port for my AdventurePilot 700/Skyradar kneeboard.)

I'm most impressed with the turn coordinator. It's both more sensitive and more stable than the analog instruments.

I've also tried using just the turn coordinator, VSI and the existing airspeed indicator as a "needle-ball-air speed" substitute, and it works very well.

I've also used the combination to fly the traditional two minute turn and I'm quite impressed.

Ted Jula, KTAN
N701TJ (Zenair CH-701, Rotax 912ULS)

Here's the photos he included of his installation:

Belite's Turn Coordinator and VSI used in experimental aircraft

Belite's Turn Coordinator and VSI used in experimental aircraft

Thanks, Ted, for your positive comments!  The Turn Coordinator is our best selling instrument, and you've helped explain why.

Our Turn Coordinator is priced at $200 SRP.  Compare our product's performance and price to any old fashioned electric unit!

You can buy it from our webstore, or from Aircraft Spruce, or from Wicks.

 -- James

Wednesday, December 7, 2011

Risk, Cannonballs and Mythbusters

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!


Risk, Cannonballs and Mythbusters

Last week, I deliverered an airplane to a new owner.  The airplane had been specially modified to meet the requirements of a handicapped pilot.  We'd modified the control stick and reduced the door entry height.  We'd also installed doors, simply to provide a little comfort on chilly fall and winter flying days.

James Wiebe flies a very special ultralight airplane from Belite; modified for a handicapped pilot

The aircraft had a number of features to increase safety:  aluminum fuel tank, extra wing spar, spring landing gear.  Even the cloth fairings on the landing gear arms cut dag, resulting in increased cruise and climb peformance.

Risk can be measured in many ways.  Flying our aircraft entails risk:  they are not certified; we sell them under the FAR Part 103 exemption which allows all kinds of privileges, in return for risk:  no medical, no pilot license, no aircraft registration.

Earlier today, I flew another ultralight aircraft:

Test Flight of a Belite Ultralight Aircraft (on the ground, actually)
 And I took some risk.  I am interested in providing a high quality product for my customers, so I realize that I must be willing to accept risk.  The engine was running roughly at high power:  a carburetor problem of some sort.  Gene and I fiddled with it, and I had it running acceptably for my test flight purpose, but certainly not acceptable for customer delivery next week.

In one or two days, I will test fly the same plane with a different propeller.  We will evaluate the performance of the propeller, because it is important to add to the body of information available to us, and to our customers as to what works best, and to our vendors, and to the greater community of aviators.

There is a financial reward, if I manage these risks appropriately.  Hopefully, this small business will continue to grow, and will eventually pay me something.  (The financial account has mostly run the wrong way.  Thankfully, that pendulum also is moving in a more positive direction.)  I've risked *a lot* on Belite. 

And now, Mythbusters.

Errantly, they shot a cannonball through the front and back of a house, off the roof of another house, and into a minivan.  They certainly didn't mean to, and before it happened, a lot of very intelligent people thought they had properly mitigated their risks.

Which goes to show, even the smartest of folks can't anticipate everything.  Risk doesn't always pay off (at least for the current account.)

I've read through many articles, I've researched the Mythbuster cannon shot literally from a bird's eye view (thanks to Google Maps), and I've seen what I believe to be factually incorrect (but irrelevant) reporting on their accident.  I read the twitter posts of Grant, Tory and Kari -- they seem to be taking responsibility straight on.  And from my limited experiences working directly with these people, I am confident they will make it right.  They are very proactive, they will rise above this accident, and they will be better for it.

Back to airplanes.

I want to help aviators fly.  This experience doesn't happen: ....

Belite Tricycle Gear Ultralight Aircraft landing
... unless I stick my neck out, invest the money, and fly the plane.  And let my customer do the same.

Risk can produce some beautiful things.

I can't help but think of our aircraft handicapped customers.  We have a couple of them.  Their ability to fly was severely eliminated by the FAA, but then they discovered Part 103 -- and our aircraft.  One of them (Eric) has become a wonderful friend of Belite, and has given Harley a beloved permanent home in our hangar.  He is allowed to risk and fly under Part 103, even though medical certificates would be denied, and Eric has received immense joy as a result.

For further background on why I say these things, consider reading Matthew 25, verses 14 through 28.  It speaks critically of people who don't take risks, and it speaks well of those who do.

Ultralight Aircraft from Belite touching down

Thursday, December 1, 2011

Beautiful Cub Yellow Ultralight Aircraft

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Belite Ultralight Aircraft, aluminum construction, 45HP motor
I flew this plane today.  Loved it!  Phenomenal performer.  The airplane is constructed from aluminum, and is available with a variety of motor options.  Shown is a 45HP motor from Compact Radial Engines.  This looks very similar to the Duct Tape Plane which was featured on Mythbusters - same color, same taildragger configuration, but with aluminum construction and a bigger engine.  This particular ultralight airplane is soon heading to a customer in Missouri.

Belite Ultralight Aircraft, aluminum construction

Belite Ultralight Aircraft, aluminum construction

Monday, November 28, 2011

Assembling a Belite Flaperon

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

Ultralight Airplane Flaperon Assembly Manual for Belite Aircraft
Last Revised November 28, 2011

Figure 1  Completed Flaperon, on a plane.

Photos © 2011 by Gene Stratton and James Wiebe.
© this document 2011.


·       CERTIFICATION STATUS:  NONE.  THESE FLAPERONS ARE UNCERTIFIED.  Use only on experimental or ultralight aircraft, at your own risk. 

·         CHORD:  12” (0.305 meter)
·         LENGTH:  105 ¼” ( 2.673 meter) (span of single flaperon, excluding mounting horn extension)
·         AREA (per flaperon):  8.77 square feet (0.815 square meters)
·         WEIGHT:  dependent on amount of paint and glue.  About 4 pounds.
·         RED LINE Vne:  80mph.  Do not use these flaperons on aircraft exceeding 80mph.
·         CAUTION:  62mph is top of green arc.  Keep flaperons centered (0 degrees relative to chord of main wing) and make only slight movements at 62mph and higher.


·         MAIN SPAR:  0.875” x 0.035” 6061-T6 round aluminum, one piece for each flaperon.
·         LEADING EDGE:  0.500” x 0.035” 6061-T6 round aluminum, one piece for each flaperon.
·         TRAILING EDGE: 1.125” preformed 3003 aluminum (Aircraft Spruce PN: 03-48900), one piece for each flaperon.
·         MAIN RIBS:  Precut 1/8” Birch Plywood, qty 28 (14 per flaperon)
·         FALSE RIBS:  Precut 1/8” Birch Plywood, qty 56 (28 per flaperon)
·         NYLON BUSHINGS:  fits over main spar and in flaperon droppers.  Qty 6. 
·         MACHINED ALUMINUM DROPPERS:  fits to nylon bushings, allows attachment to your wings.  Qty 6.  Machined from aluminum.  Parts are “heavy duty”, having replaced an earlier design which wasn’t as beefy.
·         CONTROL HORNS:  One for the left and one for the right dropper.  Made from welded steel.
·         RIVETS:  Qty 8, use four to connect each control horn. 
·         ALUMINUM SHEET:  0.016” thickness, Qty 16, use to create ‘boxes’ at each end of flaperon, also around flaperon machined droppers.
·         BALSA WOOD:  used to create rounded end on far end of each flaperon. You should have 24” of 1x1” balsa.  Makes two end caps.
·         NUTS, BOLTS, and WASHERS (used to attach flaperon to wing).  Qty 12 of each.
·         BLUEPRINTS in electronic form – you print.  We can email these to you.
·         MANUAL (this document) in electronic form – you print.  We can email this to you.


·         GORILLA GLUE
·         WOOD SEALANT such as exterior polyurethane
·         FABRIC COVERING and associated materials (fabric glue, primer, paint…)
·         CLEANING SUPPLIES (sandpaper, scotchbrite, acetone…)
·         TOOLS (normal stuff like clamps, pliers, aviation metal snips, riveters…)

·         You will need a work area, completely flat, allowing you to build a flaperon.  A minimum size of 18” by 10 feet is recommended.

·       In the event that you have any shortages, you MUST notify us within 14 days of receipt of this kit.

1.      Preparation.

a)      Ensure that your work area is absolutely flat and big enough (10’ x 18”).
b)      Read these instructions through at least three times before doing anything.  Ensure you understand everything before doing anything!
c)      Remember, you are building a LEFT and a RIGHT flaperon.  Please don’t build two left flaperons (or two right flaperons). 
d)     Remove plastic film from trailing edge material.
e)      Clean up all aluminum using scotchbrite and acetone, as required.
f)       Trim and sand all plywood parts to finished shape.  (Remove the excess tabs).  Check that they fit over the spar tube, and that the leading edge tube also fits in the front notch of the rib.  Sand as necessary.  We like using a round drum sander, such as are commonly used with a Dremel or electric drill.
g)      Ensure that nylon bushings fit over spar.  Ensure that they also fit inside machined droppers.  Sand inside and outside of nylon bushing as necessary.  Final fit should be ‘butter smooth’.  Absolutely no friction allowed.  Flaperon dropper should flop and swing under its own weight.  IF YOUR NYLON BUSHINGS ARE “OVERSIZE”, YOU MAY NEED TO MOUNT THE NYLON BUSHINGS IN A DRILL CHUCK AND TURN THEM DOWN TO THE CORRECT DIAMETER USING A MILD RASP OR SANDPAPER.   
h)      BEFORE YOU GLUE ANYTHING, make sure the surface is roughed up with sandpaper and absolutely, completely clean with acetone.  This is absolutely necessary to get a good glue bond to aluminum. 
i)        A note on Gorilla glue:  Our design has all of our ribs ‘locked’ in place by design, and the glue further immobilizes them.  This is true in our flaperons, and also in our wing design.  We use Gorilla glue in some locations because it adheres to materials extremely well, and because it is not used as a structurally critical bonding material.  Also, Gorilla glue expands enormously, so use sparingly.  Read the instructions on the glue container.  We like to have water available in a misting bottle, so that it can be sprayed lightly on components which are to be glued.

2.      Test Fit Ribs and Bushing/Droppers

a)      DON’T GLUE ANYTHING until specifically instructed.
b)      Slide all of the ribs, false ribs, bushings (with droppers) onto the spar.  Sand out the holes as required.  Remember, each rib has a top and a bottom, because the airfoil is not symmetrical.
c)      Using the blueprints as a dimensional placement guide, determine where to place all parts.  You may wish to place tape on your bench to mark locations, as shown in our photos.
d)     ******* NOTE *******, although not shown in our photos, place an extra false rib on each side of the flaperon droppers, at approximate locations of 46”, 47 ¼”, 93”, and 94 ¼”.  These will help you when it comes time to glue aluminum sheets on the top and bottom of these box locations.  If you forget to put them in now, they are tough to get in later. 

Figure 2  Sliding the Ribs over the spar

Figure 3 Another view of sliding the ribs over the spar

3.      Glue the Main Ribs

a)      MAKE SURE you have all parts slid over the spar and properly oriented.  If you forget them now (or have them upside down) it is very hard to fix later.
b)      GLUE:  the main spar to the main ribs.  Clamp the main ribs to the work bench, as shown in the photo.  We use a glue syringe and minimal amounts of Gorilla brand glue.  MAKE SURE that everything is absolutely square.  Allow glue to set.

Figure 4  Clamping the main ribs to the workbench

4.   Glue the Leading Edge, False Ribs

a)      Clamp the leading edge (0.500” round tube) to the flaperon assembly, as shown in the photos.  This locks all of the main ribs and false ribs in position.  Make sure everything is absolutely square.  You can hang the assembly off the end of your bench, as we show in the photos.
b)      GLUE:  the leading edge into position with Gorilla glue to all ribs.   Also glue the false ribs to the main spar.

Figure 5  Gluing the leading edge, false ribs, and main ribs

Figure 6  Letting the flaperon hang from supports while gluing leading edge

5.   Trailing Edge

a)      Using a flat pliers, smash the trailing edge material so that it matches with the locations of the main ribs.  See the photos.  Don’t use a pliers with serrations, as it will scratch your aluminum.
b)      ENSURE that the insides of the trailing edge are substantially roughened, wherever it mates with a rib.  You’ve got to do a good job of roughening, so that the trailing edge will remain glued in place.
c)      GLUE the trailing edge into position with Gorilla glue.

Figure 7  Trailing edge showing 'smash' detail

Figure 8  Trailing edge being fitted

Figure 9  Trailing edge being glued

6.      ‘Box’ Fabrication.

a)      Each flaperon is boxed at four locations, using aluminum sheeting:  at each end of the flaperon, and at the two locations where the flaperon droppers are attached.  The boxes are composed of a top sheet and a bottom sheet.
b)      Make sure the aluminum sheets are of the right size.  Make sure the slots (for the droppers) are cut to fit.  Trim as necessary. 
c)      ROUGHEN and CLEAN the aluminum sheets, so that the glue will adhere.
d)     Glue into position.
e)      ABSOLUTELY, POSITIVELY DO NOT allow glue to get close to the nylon bushings and droppers.
f)       We built our units without rivets on these box structures.  You may choose to use rivets along the attachment to the trailing edge, if you desire.

Figure 10  Tip box skin glued and clamped

Figure 11  Tip box after clamps removed, before clean up and trimming

Figure 12  Another view of tip box, top down  (Excess spar to be cut off)

Figure 13  Root box.  Don't cut off the root spar!

7.   Trim ends of flaperons; trim glue.

a)      If your spar, or trailing edge, or leading edge extend beyond the outside rib, trim them flush using a band saw (or hacksaw).  Sand smooth.  DO NOT trim off the main spar on the inside rib – you need this ‘root’ section to install the control horns.
b)      Sand off all excess glue.  If you were neat with your glue application, this is not a big problem. 

8.   Attach Balsa end blocks

a)      Glue a piece of balsa to outside end of flaperon.  Use gorilla or wood glue.
b)      Carve and sand to produce a pleasing aerodynamic appearance.

Figure 14  Balsa end cap, carved and sanded.

9.   Apply sealant to wood.

a)   Spray or brush on two coats of a good weather resistant wood varnish on all wood surfaces.

Figure 15  Protect the wood by giving 2 coats of exterior varnish.

10. Covering.

a)   Cover with lightweight dacron fabric, prime, and paint.

11.  Check Fit to wing assembly; install control horns.

a)      After you have assembled the wings, clamp the flaperon droppers to the wing assembly to check fit.  Slight adjustment of wing rib placement may be done to compensate for fit.
b)      BEFORE INSTALLING CONTROL HORNS, ENSURE that wings, when folded, allow control horns to overlap.  This is a tricky and critical step.  Slight offset of control horns allows this.  This means you must build the wings, and test fit wings on the fuselage, before installing control horns!
c)      After test fit is complete and perfect, install control horns using four rivets (supplied) and 3M 2216 glue (not supplied).  Control horns are to be placed 90 degrees perpendicular to flaperon chord.

Figure 16  View of uncovered flaperon in test fitting to wing (NOTE: aluminum box structures not yet done)

Figure 17  Another view of uncovered flaperon (NOTE:  aluminum box structures not yet completed)

Figure 20  Quartering view of full left flaperon

Figure 21  Root of right flaperon after installation. 


Thursday, October 27, 2011

Aluminum / Carbon Fiber Spar Loading to 6Gs -- Stunning Load

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

I have some really stunning load test pictures of our aluminum and carbon fiber spars.  But before we get going on them, here is some necessary preamble, given our recent fantastic showing on MythBusters:

If you are looking for Belite Aircraft's production photos from MythBusters, click here.  We were thrilled to be part of the "Duct Tape Plane" episode!

If you would like to follow James' tweets, @jamespwiebe is the handle to find on twitter.

If you would like to go to the main Belite Aircraft website, here is the link to follow.

Now, on to the spar loading.

Extremely long time blog readers may recall my tests of carbon fiber spars a couple of years ago.  I wanted to repeat that testing, but this time I wanted to test both our current aluminum spars and our carbon fiber spars.  And I was pushed to increase the load test from a 4G test up to a 6G test, which I did. (Thanks, Mike!)  Also, the length of our spars had increased from 11.5 to 12 feet, as we've increased wing span (and also the wing chord.)  And we had switched vendors for both the aluminum spars and the carbon fiber spars. So it was time for another test, and time to push to new limits in our testing.

This is a simple spar loading test, not a wing loading test.  Of course, the airplane has two wings and each wing has two spars.  We make an assumption that each one of these four spars is 'carrying' one fourth of the total weight of the airplane.  Since our gross weight of our Belite is 550 pounds, the 6G loading of the entire wing structure is 3,300 pounds -- more than 1.5 tons.   Therefore, the per spar loading is 825 pounds.  That's a lot of weight for a single spar to hold.  (The aluminum spars weigh 7 pounds; while the carbon fiber spars weigh 4 pounds, so they are capable of supporting 100 to 200+ times their own weight.  Wow!)

The distribution of weight on the spar loading test spread the load over the length of the spar, with weight added at each location where a rib would be attached.  Also, the spar is supported at the root (where it attaches to the fuselage) and at the strut attach point (where a strut would transfer load to the fuselage).

So here's a photo of the outcome with the aluminum spar test:

6G Spar Loading Test on Ultralight Airplane (Belite Aircraft)
And here's some individual shots:

End Section of the aluminum spar -- one of these rib/weight locations is overloaded, even for 6Gs.

Mid Section of the aluminum spar

Root Section of the aluminum spar

We also did the same test with a carbon fiber spar.  Here's a photo of the outcome:

6G Load Test on Carbon Fiber Spar
The carbon fiber spar is covered in a protective plastic film.

I accidently overloaded the aluminum spar on the second to last outboard rib position, so I labeled the aluminum spar photos 6G+  :-)

The aluminum spar showed absolutely no bend after the weights were removed -- it returned to a perfectly straight attitude.  In other words, this wasn't close to being an ultimate load test.  There's lots more strength hiding in Belite's spars.  Likewise with the carbon fiber spars -- the bend is very mild in the above photo.

Who knows how much more it could hold before it would snap?  (This test does not cover other elements of the wing design, such as the lift struts, ribs, etc --- that work is saved for another day.)

IF I WAS CHOOSING, I would prefer the carbon fiber spars in my own airplane, (they are a $2200 option) but the aluminum spars prove to be an economical and beefy answer as well, albeit at a weight penalty of about 11 pounds per airplane.

Thursday, October 20, 2011

Mythbuster Duct Tape Airplane production photos

Please note: James' blog has moved to a Wordpress site. To access it, please visit All posts have been transferred to the new site, and all new posts will only be accessible via Wordpress. Thank you for your interest!

It's time to reveal lots of production shots from Mythbusters and the Duct Tape Airplane, which is an ultralight aircraft from Belite Aircraft!

Reminder:  All photos on this website are (C) 2011 James Wiebe.  If you are interested in high resolution photos for publication, contact James.  Do not copy my pictures!

The show aired last night.  Viewers responded by looking us up on the web and it crashed our website!  Now it's back up.

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Now, the definitive collection of pictures from the production of "Duct Tape Airplane" on Mythbusters, using a Belite Ultralight Aircraft:

Kari, Tory and Belite Ultralight Aircraft

Duncan and Belite Ultralight Aircraft

Duncan and Belite Ultralight Aircraft

Eric is Grizzly

Overflying Mythbuster crew in a Belite Ultralight Aircraft

Gene, James, Kari, Tory, Grant and Duct Tape Aircraft (Belite Ultralight Aircraft)

Grant and Tory work on Belite Ultralight Aircraft

Grant confirms myth on Duct Tape Airplane (Belite Ultralight Aircraft)

James and Jennifer in map room at Mythbusters

Kari Byron and Be

Kari Byron dancing with Belite Ultralight Aircraft in background

Kari, Grant, Tory and Duct Tape Airplane (Belite Ultralight Aircraft)

Kari Byron with sweet smile

Fuel, Kari Byron and Duct Tape Airplane (Belite Ultralight Aircraft)

Lauren (Director) with Mythbuster Trio and Benny (1st Camera)

Kari Byron with Belite Ultralight Aircraft

Kari Byron, Grant and Tori and Duct Tape Airplane (Belite Ultralight Aircraft)

Overflying the Mythbuster production group at New Jerusalem Airport in Belite Ultralight Aircraft

Another shot of the Mythbuster crew on the ground

Kari Byron enjoys the sunshine, Duct Tape Airplane and Grant

Tory:  Why so concerned?