Ultralight Aircraft for disabled pilot

A Belite customer challenged us to improve cockpit access for our Belite ultralight aircraft; the customer has some challenges; especially with his legs.  Getting in and out of our aircraft is a real challenge.

As a result, we were pleased to improve cockpit access by lowering the fuselage right side door height.  We cut off the existing steel tube and welded a tube about 5 inches lower; with additional length on the tube to add strength.

Here's a photo:  compare the near and far sides of the fuselage to see the difference in the steel structure.  You can see that the nearer side has a lower entry level. 

Aluminum Plane: Real Flight Data Graph

One of the joys of this project is the performance of the product:  the aluminum plane rocks.

Here is a "GPS Essentials" flight data chart from a recent flight in Aluminum Plane #1:

Belite Ultralight Aircraft Performance Graph

I marked two locations with yellow dots.  The difference between these dots in time is about 3 minutes, and the altitude gain is (2070-1500) = 570 feet.  This is a calculated climb rate of 225 feet per minute.  With a forward airspeed of about 43 mph in the climb, the actual climb angle was about 5 degrees, and the deck angle was probably around 12 degrees.  Climb rate was NOT maximum.  (although it was probably close).  I weigh 200 pounds, plus some gas on board of course, and density altitude was about 3300 feet at ground elevation.

All this with a tiny 28hp engine.

You can also see some two pass runs, demonstrating cruise speed.  With the wind, ground speed averaged about 64mph and into the wind, ground speed was 47mph.  The average is 55.5 mph, once again, with a 28hp Hirth F33 engine.

Fun, fun, fun!

- James

"This Belite Be No More"

And this is a very sad story, with one fantastic testimony to the crash worthiness of our airplane.

The 80+ year old pilot was observed to take off in the Belite Superlite, barely gaining enough altitude to clear a fence.  Apparently, the pilot did not command the airplane to turn in any direction, climb, or descend back to the ground, which was just a few feet below him.  Nor did he retard the throttle, which was reported at 'full' by an observer.  (The Superlite is capable of climbing out at fairly steep angles.)

After continuing in this manner for a handful of seconds, he crashed into the side of a distant steel building, still under full power, still just a few feet above the ground.  I have not seen the accident in person, but I do have one photograph.  It seems to show a very hard impact of the left wing tip, then impact of the main structure of the fuselage.  The wing ribs and spars are carbon fiber, and the fuselage is chromaloy steel -- all very tough stuff.

The pilot was wearing his seat belt / shoulder harness, and escaped the accident with broken ribs.  The cabin structure of the Belite, along with the safety harness, probably saved his life.

The metal gas can did not rupture.  (It is optional equipment.)  The parachute did deploy at impact (probably due to stretching of the release cable in the accident.)

We are very saddened by this accident and wish the pilot a speedy and full recovery.

Belite Ultralight Aircraft Accident

More Info: Ultralight Aircraft Aluminum Fuselage

The #2 Aluminum rear fuselage is taking shape nicely.  This particular aircraft is destined to be a tricycle gear airplane.

Everything you see here is weighing in at about 33 pounds, including tricycle mods.  I am pleased.  We had taken a 'weight bump' but have gotten some of the weight back out by trimming excess off cross members.

We're waiting to mate this fuselage with carbon fiber spar wings; we're currently out of stock on the carbon fiber and waiting for a shipment to come in.  As a result, the fuselage will not be flying until around Thanksgiving.  It is scheduled to deliver to a customer in December.

Please note the gas tank / cargo compartment.  It's designed to hold a 5 gallon plastic tank, for easy swapping.

The purpose of the side aluminum sheet panels is to spread landing gear loads from the gear into the fuselage.

It would be very easy to 'metalize' this entire airplane.  I hope some customer chooses to do that.

Belite's Ultralight Aircraft Aluminum Fuselage

Close up of gas compartment.  Optional lid over this, along with panels to close off the compartment.

Detail of tail section.

Tail Section, another view.

Belite's Aluminum Ultralight Aircraft fuselage

Phenomenal Performance from Yellow Aluminum Ultralight

You'll get three things from this post:

a)  I can't stop glowing over the phenomenal experience I had flying our aluminum prototype airplane.  It was configured with a 28HP engine and the performance was very close to what we've experienced with our 50HP airplanes.  The reasons why this all worked:  light aluminum construction, a big wing with an awesome low speed coefficient of lift, (bigger span, bigger chord), bigger flaperons, and the exact right prop/engine combination.  I took a GPS chart on my phone of the flight and will try and figure out how to post it.

b)  I can't stop glowing over the phenomenal experience I had while practicing off-field landings in the next door hay field -- my able assistant Gene captured the STOL landing to perfection.  I cranked in two notches of flaps and nailed the touchdown spot within 15 feet.  After rolling to a stop (and I didn't use maximum braking), position was noted. Gene and I went and measured the touchdown roll with our tape -- 100.5 feet (that's 100 and one-half foot) from touchdown to stop.  The landing was made full stall (and was nearly full STOL, for those that grok the difference) and the plane dumped onto the hay from about a foot or two off the ground.  The steel spring gear just absorbed it all, you can see the tailwheel disappear into the grass in one of the pics that Gene took, and nuthin' bent.  Just saying.    Oh My what fun ------ Steve you will like your plane.

c)  The plane is really pretty.

That's three things.  Here's picture proof.  Let's start off with three pictures of the plane just flying around.

Belite's Aluminum Ultralight Aircraft flying overhead

Belite's aluminum ultralight aircraft

Belite's aluminum Ultralight Aircraft, passing under the sun

Now let's look at that landing sequence, showing short final into the hay field with the 100 foot stop:

Belite's aluminum ultralight aircraft, short final to the hay

Belite's aluminum ultralight aircraft, short final abeam the trees

Belite's aluminum ultralight aircraft, closer to the hay

Belite's aluminum ultralight aircraft, 25 feet up

Touchdown!

Smack that tail down

Rolling through the hay

Already stopped!!!  Turning

Yeah Gene, I did it.  :-)  Nothing broke. 

One final pic after I taxiied back around the field and up the runway..

Pretty Plane, Awesome Performance, I like it...

Service Bulletin 8-24: Rod End Bearing needs cap washers

We had a partial failure on a rod end bearing, on a lift strut.  The point of failure is where the lift struts attach to the fuselage.  The internal structure of the rod end bearing began to fail, and as a result, the rod end bearing might have slipped over the head of the bolt.   If this had happened, there is a strong possibility that the lift strut might have detached from the bearing bolt on the fuselage, with damaging or catastrophic results.  A simple solution is the addition of a cap washer.  We recommend immediately adding these washers to your aircraft before further flight.  It is important that the top washer is trimmed so that it does not hit or rub the lift strut. 

Failed Lift Strut Rod End Bearing

Another view of Failed Rod End Bearing

In order to prevent these rod end bearings from slipping over the head of the bolt, we are installing cap washers:

Cap Washers, with one trimmed

Here is a photo of the reassembled lift strut attach point, showing the rod end bearings and the cap washers.:

Cap Washers installed on lift strut

The bolt has been reinstalled, complete with quik release key (safety wire is of course also acceptable).

If you need these washers, please contact us and we will supply them at no charge.

The integrity of the rod end bearings should be inspected with each preflight.

Nice Mythbuster Article posted

Carrie Rengers of the local newspaper posted a nice article online about Belite, myself and Mythbusters.

You can read it here.

Rear aluminum fuselage assembly

Here's some photos showing the buildup of the rear of the fuselage in our aluminum ultralight airplane.  Most of the aluminum is 2024 series, but some is 6061.  The amount of labor to get to this picture is about 20 hours.  Still remaining is gusset work, along with a few odds & ends. 

I love clecos!

This is not hard work.  It is a blast to lay it out and have it look like an airplane within two days.

The rudder comes pre-welded, as shown in the photos.

I'm in this picture, but you can't see me.  I'm holding the board up from behind.

Gussets not shown.  The bottom wedge with all the clecos is actually 4 layers of aluminum.

I love the rear section of the fuse.

This bulkhead will have the nylon bearing block for the elevator push pull tube.

Gas tank platform.

One last look at the tail.

aluminum fuselage update

Here's some photos showing some of the ways our fuselage design has mutated from 4130 steel.  I've also made some comments on strength.

The front of the fuselage is made from 6061T6 aluminum, and is welded.  The rear of the fuselage is made from 2024T3511 aluminum, and is riveted.

The hallmarks of this design is that it is very light, very strong, and easy to assemble.  Let's look at some pictures.  The first picture shows that the primary vertical members are 1.0" aluminum square tubing, with .063" walls.  Although the temper is 6061T6, the welding is assumed to reduce the strength.  This particular tubing doesn't have the heavy loads.  However, it is also a primary safety mechanism to enclose the pilot in the event of an accident, so we still want it to be strong.  Assuming 0 temper, the strength of this material is about 4,500 pounds per tube cross section.

1" square tubing used in Belite ultralight aircraft

 

 

The front section of the fuselage is where the engine mounts attach.  We've reinforced this section with 4" gussets.  Here is a gusset at the top of the front fuselage:

Gusset reinforcement

 And here is a gusset on the bottom of the front fuselage:

Gusset reinforcement is on bottom of fuselage

 

 

Now let's look at the front spar crossover.  It is constructed of aluminum tubing (about .080 wall) with reinforcements in both axis.  As a result, it has a critical length of about 12 times its diameter, which means that the effects of "Euler's Buckling" have been reduced or eliminated.  At normal loading, this spar crossover has about 650 pounds of force pushing through it.  At a 4G load, it would have around 2600 pounds of force.  Assuming 6061T0 temper (welded), the cross section strength of this material is about 4000 pounds.

Front Spar Crossover with reinforcements.

Now let's take a look at the rear spar crossover.  We've reinforced it with some 1" square material.  The failure strength is substantially stronger than the front spar.

Rear spar crossover with reinforcement

 

 

 

Here's another view of the rear spar crossover:

The above photo shows the bracing.  The braces help prevent the cockpit from torsionally twisting.

rear spar crossover with bracing shown

The pilot's seat also gets some strengthing:

0.5 x 1.0 aluminum tubing added to pilots seat

Tricycle gear versions of our planes get extra cross channels on the bottom, along with more bracing in the side cabin area:

Tricycle gear airplanes get even more cross channels

 

And now let's show how the rear fuselage is added on.  We start with four longerons built from 2024 aluminum, with an angle size of 0.875 x 0.5 x 0.063 inches.  We then add some bulkheads, a vertical stabilizer, and some rivets.  We also use gusset plates.  Since there is no welding in the rear of the fuselage, the 2024 is an excellent choice.  (You can't weld it, but good golly goodness is it strong.)  Tensile strength of the longerons is off the charts:  each longeron could lift nearly 5900 pounds.  In a few more days, I'll have some photos of the completed rear fuselage.

Rear fuselage of Belite's aluminum airplane

rear view of the rear fuselage of Belite's ultralight aircraft

front view of the fuselage, it's all coming together

Broken Flaperon Repair

We just repaired our proto aluminum airplane.  We put triplers on the root flaperon riser, and we put a doubler on the opposite end flaperon riser.  We did this on both flaperons, left and right.

The doublers were reinforced with JB Weld (cleaned and roughed surfaces first) and the extra new pin bolt is a stainless 6-32 bolt with a locknut.

In the second photo, you can faintly see the crack on the original flaperon riser.

Here's the pics:

The original failed part is in the middle of the aluminum sandwich, above.

6-32 stainless bolt with washer.

Right wing riser with reinforcements.  This one wasn't cracked.

Outboard flaperon riser with doubler.  We reinforced both outboard left and right flaperon risers.

Inboard flaperon riser with triplers, JB Weld, and bolt (which will be trimmed).