What is the world's lightest aircraft?

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I'm asking:  what is the world's lightest airplane?

I'm not asking what is the world's smallest:  that honor may be held by this airplane, the Bumble Bee II.  Read about it on Wikipedia.

The Bumble Bee II is definitely not light, weighing in at 396 pounds.  Any Belite is lighter than that.

But Guinness points to an aircraft called the Wee Bee as the world's lightest.  (I find the name Wee Bee very interesting!)

You can read about it here, and they claim it had an empty weight of 210 pounds.   It looks fairly fatal, because the pilot rides on top, face first.  Any accident is going to be a killer:

The 1949 Popular Science article this photo is taken from is a must read.

And it's a Wee Bee.  Just can't get over that.

A Belite can be built with a weight of 210 pounds.  But Belites are definitely not the lightest planes in the world:  what about the Easy Riser, of John K Moody fame?  It weighed a little more than half what our planes weigh.

And also, what about various Human Powered Aircraft?  These have been around quite awhile. Here's a pic of one, in flight:

Human Powered Gossamer Condor, in flight

So I'm really asking:  what is the world's lightest, gasoline or electric, human carrying airplane with an enclosed cockpit?

Here are the rules:

1)  Must be gasoline or electric.  (Disqualified Human Powered, which weigh less than 100 pounds...)

2)  Must have an enclosed cockpit.  (Disqualifies the WeeBee)

3)  Must be fairly conventional:  wings, engine, tail, or canard.  (Disqualifieds weird stuff, like balloons.)

Brand New Simonini Engine for sale!

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


The spring cleaning sale at Belite continues....

At Belite, we officially support a couple of different 2 stroke engines:  Hirth (German) and Compact Radial Engines (Canadian).  Another type of engine that we took a look at a long time ago was Simonini (Italian).   I decided not to support this engine type in the Belite.  I believe they are very popular for some other markets (for instance, Powered Para Gliders...).

So I am offeirng a brand new Simonini engine for sale.  I *think* it is a Simonini Mini 3, which you can read about here.  After I purchased it, we never started it up.  (Simoni makes several different engine models which look similar).

I'm offering it without reserve.  It will be a really great deal for someone.  I see that Simonini is offering this engine at the new price of $4144.

Starting bid is $25.  This engine will be posted for sale on eBay.

Simoni Engine for sale

Simonini Air Filter

Simonini Carburetor

Simononi exhaust manifold

Simonini motor mounts

Simonini Muffler mounts

Simonini Muffler

Simonini redrive

Simonini Muffler mount

Calculating Center of Gravity in a Belite Ultralight Aircraft

Please note: James' blog has moved to a Wordpress site. To access it, please visit http://jameswiebe.wordpress.com/. 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 easy to calculate the Center of Gravity in a Belite Ultralight Aircraft!

*** NOTE:  This post is for taildraggers.  I have posted an additional blog entry on how to calculate CG in a tricycle gear airplane.  After reading this taildragger post, you can read the additional post on calculations for a tricycle gear plane HERE. ***

1.  Ensure that the aircraft has everything on board that should be in place for finding the empty weight and CG.  Using a level, put a support under the tailwheel and make sure that the plane is level front to back and side to side.  You'll need to lift the tailwheel off the floor by somewhere around 20 inches.  The lower door line may be used as a level line.  Here's what a level Belite looks like:

Belite Ultralight Airplane, Level, Side View

2.  With the aircraft level and all fixed equipment installed, record the scale readings and weights.  The fuel tank should be empty.

Right Wheel = ____________ Pounds
  Left Wheel = ____________ Pounds
     Tailwheel = ____________ Pounds

3.  Verify and recalculate as necessary, the ARMs for each wheel location.  This is done relative to the forward face of the firewall.  You can use a plumb bob from the firewall to mark the location on the ground, then measure back to the middle of the main wheels and the tailwheel.

Typical Main Wheel ARM = 20.6 inches (yours may vary)
Typical Tail Wheel ARM = 162.6 inches (yours may vary)

Measuring ARMS for CG calculation on ultralight aircraft

We also need to know where the pilot is located and the fuel tank.  For our sample airplane, we will assume 36.9 inches for the ARM of the pilot, and 58.6 inches for the ARM of the fuel.  You are encouraged to verify these ARMs as well.

4.  Now let's do some calculations on weights, ARMS, and moments.  We'll add in the pilot weight, and also the weight of some fuel.

Weight, ARM, moment

Right Wheel 124.7 x 20.6 = 2568.8
Left Wheel 124.7 x 20.6 = 2568.8
Pilot 200.0 x 36.9 = 6273.0
Fuel 30.0 x 58.6 = 1758.0
Tailwheel 28.2 x 162.6 = 4585.3

And let's add up the weights and moments:

In this example, the weight adds up to 507.6 pounds (with gross aircraft weight of 550 pounds, so that's good) and the moments add up to 18861.0.

Dividing total moment by total weight, 18861 / 507.6 = 37.16.  This means that the CG is 37.16 inches.  Since our aircraft has a range of 34.5 to 39.1, we are good to fly.

5.  Further exercises.

You'll want to determine CG at a variety of pilot weights (to match your own weight) and fuel conditions.   In our example airplane, the CG is 35.81 at a zero fuel condition, so the CG moves forward as fuel is consumed.

Cowl on twin cylinder ultralight airplane

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


This is my third post of the day!.  Earlier today, I've already written and posted about John K Moody, father of ultralights, and also about our upcoming posting of a used 1/2vw engine for sale on eBay.  Scroll down this blog and / or search and you'll find dozens (actually, over 200...) articles about topics of interest to ultralight and experimental aircraft builders.  Also an occasional article about my dealings in the world of computer forensics.

We just finished fitting the cowl on the Turquoise airplane.  Gorgeous.  3 quick pics: