Friday, June 11, 2010

Thorough Belite Superlite Review Published!

We have obtained the right to republish the flight review on the Belite Superlite, written by Scott Severen in Light Sport and Ultralight Flying magazine.  The Superlite is our FAR Part 103 ultralight, and provides superlative performance, while consuming 3.4 gallons per hour of gasoline.  It is available in prices ranging from $28,500+ (assembled and flying), depending on options.  All configurations include the Hirth 50HP engine, which looks like an aircraft engine, and includes dual ignition.  For the money, this is the highest performance small aircraft in the country.

This extensive review covers the flight characteristics of our Superlite plane, along with an excellent description of our assembly facility.
 
Please enjoy the reading and pictures, which you may find here in PDF form.  Alternatively, read the 'text only' version after clicking on this alternative text only link:

My thanks to Scott for writing such a thorough article.



Superlite by Belite Aircraft

By Scott Severen

Ultralight Vehicle and Flight Review

Simple. Sophisticated. Strong. These are the first impressions after a brief walk around of the Superlite ultralight recently introduced by Belite Aircraft of Wichita, Kansas. I have been anxious to see this new entry to the ultralight world since learning of its release in June of 2009, and have followed Belite Aircraft’s progress since!

After visiting with company owner and product innovator James Wiebe, one will quickly learn Belite aircraft are not simple. It is an art to make something appear simple. It takes ingenuity and passion to take complex problems and distill them to appear as a simple solution.

The Superlite is an exercise in the application of contemporary technologies to an existing, well developed design, taking advantage of its significant pedigree: the Kitfox Lite, ultralight version of the Kitfox experimental and light sport aircraft. Kitfox has been in business over 25 years and has produced over 4500 kits to date. The ‘Lite hit the scenes in 1998, I believe, and there was quite a bit of excitement with Kitfox entering the even lighter side of flying. It was a very successful design as evidenced by the resources poured into the project and the high number of sales. The materials and methods introduced by Belite Aircraft incorporate modern construction methods to make the vehicle compliant to the weight parameters described in FAR Part 103.

Sophisticated

While load testing and compliance to airworthiness standards are not required of Part 103 vehicles, Belite’s products are load tested and are in the process of certification to the German BFU‐95 standard. The standard is pretty thorough and conformance establishes credibility and strength in the design.

Let’s understand The Company

James and Kathy Wiebe, two amiable, smart, hard working Americans sold a company they grew (that was involved with digital forensic computer storage devices) and later saw an ad on Barnstormers listing a “manufacturing opportunity”. The opportunity was to purchase the assets ‐ tooling, inventory, etc. “as is” for the Kitfox Lite. Part of the deal, though, was to separate the identity from Kitfox to avoid any association with the existing Kitfox aircraft or company.

This provided an avenue for Wiebe to combine his passions of creating, designing and solving problems with flying, and for Kathy to apply her management and marketing expertise to another field her entrepreneurial husband was smitten with. An older Kitfox ultralight was acquired and James got busy figuring out how to incorporate his knowledge of current technologies to ensure the new ultralight would be Part 103 compliant (it is understood that many ultralights have difficulty meeting the definition). In fact, James wrote a case study on just that, available at the website: www.beliteaircraft.com. Look under the “How it’s Built” tab. While we are at the website, I have to say, the Wiebe’s provide a great amount of easy to find information there. Unusual for a manufacturer is James’ blog: We Be James. Clever name. Not that blogs are anything new, but the way this is
incorporated is great. James has recorded his ultralight adventure along the way, along with an occasional interesting introspective.

The Wiebes started out operating in early 2009 at Jabara Airport KAAO, a municipal airport in East Wichita. This served the purpose initially, but was not an ideal venue. In February of this year, James struck a deal to move into a couple of hangars at Wichita Gliderport, a vast grass strip about 3 miles east of Jabara. Actually, it is two great 2600 foot grass strips separated by some trees and field areas – a great layout for alternative landing sites when you are playing with new engines, propellers and other things that seem so loud after they become so quiet. The expanse works well for the busy glider club as well as another ultralight business, the Mosquito ultralight helicopter, that captured this scribe’s interest…. more on that in an upcoming issue….

The Facilities

I visited Belite’s new facility just four weeks after they moved in and was impressed with all the work that had apparently been accomplished in such a short time. The facilities are not fancy – you’re not going to be successful in the ultralight biz in this economy by placing resources where they are not needed. They are very functional. “Form follows function” is employed here, along with production manager Gene Stratton who, aside from his many talents, is a master at production/shop layout, and a craftsman to boot! At the time of this writing, there is one other full time and three part time company Beliters.

You enter Belite in the planning and production hangar. First are modest office and planning areas. Next is a welcoming break area, situated next to a large window, required for keeping track of deer, hawks, and various other flying matter that use the runway! The front of this hanger is the “clean room”. There are two large tables where either wood ribbed with aluminum spar, or carbon rib with carbon spar wings are laid out, and parts bonded. The Superlight flown for this review uses the carbon fiber materials, so most of the focus of this article will be in that direction.

How’s this thing put together?

One example of ingenuity (and there are many) that separates this plane from is predecessor replaces typical drag/anti‐drag struts or cables with carbon rope. The rope, about 1/8” in diameter, is wrapped around the leading edge root, then routed aft and outboard to the trailing edge spar at about 45 degrees (drag), wrapped around the spar, then routed forward and outboard to the leading edge spar (anti‐drag), again at about 45 degrees, creating a zigzag pattern from the wing root to the wing tip. Simple, sophisticated and strong.
The rib is a beautiful piece of work: carbon and foam core sandwich with wood caps. Truly composite. The wood provides surface area for the fabric cement, and the cement is happier anchoring to wood. The ribs are slid onto the training edge spar and fit against the leading edge spar. Three carbon false ribs separate each full rib. The rear ends of the false ribs are supported by and bonded to a ½” x 035 aluminum tube that runs the length of the wing, passing through the full ribs as well. When all is lined up correctly it is bonded. The wings be lite and they be strong. 14.5 pounds each. The complete wing with flaperons, covering and hardware comes it at about 25 lbs. and has been static load tested to 4 g’s. 6g load tests are next (and required for the BFU‐95 certification). The wood and aluminum wing weighs about 31 lbs. The completed carbon fiber wings look so very clean and precise it is a shame to cover them with fabric!

On the root end of the wings, short aluminum tube spar sleeves are bonded in place where the fuselage attach bolts/pins pass through the spars. While carbon fiber is very strong, it does not like point loading, so the aluminum tube spreads the loads at the attach points and provides bearing area. The folding wings pivot about the rear spar bolt after disconnecting the front spar pin.

The wing struts attach to the spars via milled 6061 aluminum fittings that are machined to the radius of the spar such that the 8‐9” fitting lays lengthways, snug against the spar. Carbon fiber is then wrapped around the spar and fitting like a tape and bonded to secure them. In the construction of the spar are sequential layers of carbon fiber “tube” added at the strut fitting area to spread the loads imposed by the strut. The temperature in the “clean room” must stay above 65 degrees for the curing processes.

Inventory is catalogued and organized against the walls and in racks throughout the planning and layout areas and towards the back. In the back end of the building is the welding area. It is evident that production, as well as R&D are going on here. Welded up 4130 fuselages are stacked on top of the inventory racks. In one fuselage welding jig was the prototype “even lighter” framework which incorporates .028 instead of the typical .035 wall Chromalloy™. More weight‐saving strategies. Engines of various sizes and types are stashed on top and under shelves from 13 hp to 50 hp, single cylinder, two cylinder, two stroke, four stroke and – I’d better stop here. Suffice to say that James Wiebe has very fertile brain cells!

How planes are put together is fascinating and important if one is to evaluate how they fly. The more you understand about a plane and its systems, the better chance you have of being prepared in the event something unusual or unexpected presents itself in flight.

Walk Around

The Superlite is a 4130, single seat, steel tube fuselage, fabric covered, carbon fiber, high wing, folding wing, taildragger, with a Hirth F23 50HP 2 stroke engine. The plane for this review weighs in at a mere 277.8 pounds, slightly more than the pilot at about 220 lbs flying weight, I am happy to report. (But more than twice as heavy as the first ultralight I built weighing in at 121 lbs – wet. Wet means you add the weight of the one gallon of gas and 3.2 fluid ounces of oil.) Since the Superlite is fitted with a BRS parachute, the plane has .2 pounds to spare (254 plus 24 parachute allowance = 278).

One thing I love about ultralights is each pre‐flight is just about an annual inspection as so much is exposed. There is an engine cowl available that this plane did not have installed, and that would reduce some ability to check all around the engine. But on this plane, it was easy to inspect the motor mounts, mount bushings and bolts, exhaust pipes and muffler, air filters, carburetors‐ yes, dual carbs, spark plugs – dual ignition, and wires, fuel pump and lines, redrive with poly V belt, prop….

Stepping to the left side of the plane, you can see control is with stick and rudder pedals (with heel brakes attached to mechanical expanding drums on 5.00 by 5” tires). Throttle and choke quadrant is on the left, as is a fuel valve, and the flap handle with three settings, 10, 20 and 30 degrees. The instrument is made of wood‐ God’s natural synthetic. Located there are the electric start (push button), and two, yes two, mag switches. This particular plane was equipped with airspeed, slip ball, RPM, EGT and CHT. After only a few minutes in the plane the flight instruments are redundant as the plane talks to you very well. But that’s getting ahead of the story. Missing is a fuel gauge. It’s normal to estimate how much time of fuel is on board to cross check the indicator, so not having a gauge is not a big deal, but I suspect many would want one. Also, you can see through the fuel line running from the tank to the engine to see any bubbles headed that way. Now that sounds like it may call for quick action if there were bubbles – and it would! Part of flying (non‐certified aircraft) is always being ready. It’s not “if” but “when”. Don’t you always fly ultralights within gliding distance to a safe landing area? Most of the time?!?!?

The generous use of carbon fiber is plainly visible in the cockpit area: the floor board, firewall, seat bottom and seat back. And those beautiful carbon wing root ribs! Up there you can inspect the pitot system tubing and the front spar pin (these are folding wings) and rear spar bolts. Right off, I noticed the four point pilot restraint. Excellent. Aside from the obvious protection a full harness provides, when it gets really rough upstairs, it can be nice to snug the body so you don’t wind up bumping your head or other body parts on the structure around you. BRS is standard, located just aft of the cockpit, with the pull handle at the front right edge of the seat bottom. Just below the parachute pack is the beautiful spun aluminum fuel tank. Lighter and stronger than the plastic tank it replaced.

Moving the aluminum stick side to side yields light forces on the asymmetric flaperons with a minimal amount of play from left and right motion, considering they are push/pull cables (Bowden℠, Morse℠ or Teleflex℠ type) . Moving the stick fore and aft operates the elevator tube actuated through a bell‐crank just behind the seat. The elevator tube routes through a bushing midway back to the tail to keep the tube in column.
A visual inspection of the rudder pedals shows two push/pull cables (Bowden™ type) that operate the rudder: one off of each pedal. This is a nice redundancy – if one cable or fitting were to fail, the other would take over. This requires a close preflight of this item to know that there is indeed a failure in either system.

Above and in front of the rudder pedals is where a lithium polymer battery for starting is located. It is designed with a quick disconnect so you don’t need to carry it with you in flight (and so the weight is not added to the empty weight.) It comes with its own battery charger so you can recharge it at night. Just like so many toys.

Nice weldments everywhere, machined fittings, clean cable, hose, and wire routings. Overall, a very nice, confidence inspiring appearance.

The struts attach just aft of the cockpit which makes for easy entrance and exit. The wing strut attach method changed since the Sebring show earlier this year. The aluminum strut tube end had been flattened, bent and welded along the edges. Now there is a large rod end bearing that threads into a fitting that is bolted in the aluminum strut. A hefty 5/16“ bolt secures the fore and aft strut rod end bearing fittings to the fuselage. The welded landing gear locates the tires just in front of the cockpit area and there is no bungee suspension on this particular plane. Just as in the mini‐MAX ultralights, the tires do a fine job of absorbing landing loads and bumps in fields. You can add bungees if you like, but of course, there are weight and maintenance penalties.

Moving outboard along the wing is a typical aluminum jury strut arrangement and further out the strut attach can be checked‐ rod end bearing to the milled aluminum bracket that is bonded to the spar, discussed earlier. The wing tips are simply squared off, with a carbon end plate. You could have cool wing tips, but they weigh something, and might add speed. Belite watches both of these items closely as they are emphatic about delivering legal ultralight vehicles. Three substantial hinges hold the drooped flaperons sturdy. The control surfaces are aluminum covered foam ribs with an aluminum spar/torque tube running the length. I understand that the plane flies quite satisfactorily with only one flaperon connected and this stands to reason when observing their generous size. I don’t plan on intentionally verifying the fact on this flight!

Walking aft to the empennage, I am reminded of the Airbike with the uncovered rear fuselage. The 4130 tail‐group is fabric covered and cable braced, top and bottom. Hinges are welded tubes with pins. All quite rigid. The upper spine of the fuselage splits to become the leading edge of the vertical fin and the other tube serves as a compression tube to the rear spar of the vertical stab and provides a lower base for the horizontal stabilizer. At the split is a graceful and convenient handhold that can be used to lift the tail for ground maneuvering. The tail spring is composite, and the tailwheel is a 125 mm Razor™ wheel, from the scooters. Awesome – if these little rubbery wheels can take the abuse that kids put on them, they must be great for a tailwheel! The wheel is kind of rubbery so it sticks to pavement (and settles on grass pretty well, too!)
A note here about the practicality of the folding wings: Wow! Often, folding wings are a hassle, and the aircraft is in a rather precarious state during the folding operation. Belite has re‐defined folding wings. First of all, sure enough, this is a 5‐10 minute operation, just as they claim: Disconnect the flaperon control cable at the flaperon, pull the front spar pin, then rotate the flaperon up as you ease the wing rearward to the fuselage. Attach a small strut from the fuselage to the wing and presto! Do the next wing. What I found remarkable, beyond the real ease of this, is: With only one wing folded and the wind blowing 10‐15 mph, the plane is solid as a rock. I rotated the plane around in the wind with just one wing folded and it just sat there. I suspect part of this is because the wings are so doggone light that they really don’t create much of an moment arm off the landing gear. At any rate – what a useful and practical system! Now you can stop to answer your cell phone in the middle of yet another task at hand and not worry. It’s a free app!

Flying!

Now for the good stuff! Getting in is easy. Set your keester in the seat ‐the struts and landing gear are out of the way so you don’t need to straddle them. Bring one leg in and over the stick and bring the second leg in. Immediately, you notice this cockpit is large enough to be comfortable for even 95th percentile pilots. The legs and knees have plenty of room. Even if you are 6’4”, your line of sight sideways is below the wings – much appreciated. This plane had no doors on it, so the effective cockpit width is just over 25 feet. Plenty of room for broad shouldered aviators and aviatrix. There is a clear panel above your head that seals the gap between the wings that I later found very useful performing turns in the air. Most of my flying time the last few years has been in low wing aircraft, and I was surprised for a second when I made my first turn to base, that the runway disappeared! You get used to little things….

Before launching, I chose to taxi up and down the runway to get the general feel of the ultralight: the rudder and brake handling, application of power, effectiveness of the ailerons and such. Suspension is fine with just the tires absorbing the bumps in the fields.

Winds were about 10 gusting to 15 mph and 30 – 45 degrees cross from the left. James suggested I first take off and land directly into the wind since there were no runway width restrictions, which I was happy to do. I could tell he was a little anxious letting a stranger take off with his baby, and I empathized with that! Full power equated to just over 5600 RPM on the ground. This 50 hp Hirth with a Tennessee 60X36 typically spins about 6150, however a throttle stop was installed to keep the little ship from flying too fast. None the less, using only about 38 hp, the Superlite accelerated pretty briskly. Not wanting to mow any grass, I did not raise the tail on this run, rather, I let the plane rotate from 3 points. After a couple of hundred feet and an airspeed near 30 mph the plane departed the runway. A prop pitched more for climb might allow you to use more horsepower at take‐off, improving short field capability and climb without having to sacrifice the top end or ultralight legality. If registered experimental, you may want to toss the throttle stop and take advantage of the extra speed with this prop, that is, if you are in a hurry for the fun to end!

The rpm increased slightly as I initially climbed shallow at about 200 fpm, knowing it was a bit gusty and not yet knowing the personality of this little performer. The Superlite is plenty stable – while there were gusts and some thermal activity, the plane felt solid in the air with plenty of control available.

Pulling the throttle back to 5600 RPM leveled the plane at about 1000 feet AGL, with the airspeed settling about 55mph. A note here – the airspeed indicator had a significant high reading error, so I am reporting the speeds I feel pretty comfortable the plane was flying (and verifying the data from my gps after the flight.) I have found most ultralights (and light aircraft) to be “fly by feel” ‐ The numbers a manufacturer provides are a reference only – what matters is what the plane does in its particular configuration and loading.

Now, I wanted to feel the harmony between the ailerons and the rudder to determine how much rudder is needed with the aileron to make a coordinated turn. This can be accomplished by rolling left and right while holding the nose fixed at a point on the horizon. The amount of rudder needed then to hold the nose where you want it gives the relationship between the control inputs. It’s a great exercise to perform in getting to know a plane. The Superlite does not exhibit much in the way of adverse yaw, but there is a little, and the rudder is very effective in setting things straight. You don’t need to lead with the rudder at all, but it sure enhances the roll when applied with the aileron input. By the way, it is easy to know if you are not coordinated in a turn – you get quite a blast of wind hitting you from the left or right if you slip or skid! No need for even a yaw string!

A couple of other interesting items here. Roll rate is under 3 seconds from 45 degrees to 45 degrees – too quick for me to get any more accurate than that. Frisky! And, when cross controlling the ailerons and rudder to the stops, and then releasing the rudder, the rudder has a tendency to return to neutral. Primary trainers or “stable” aircraft rudders will often return to neutral (sometimes through a mechanical assist such as a spring arrangement). On aerobatic aircraft, the rudder may just stay put. The Superlite is stable enough to be comfortable but not restrictive.

It was time to check flight at critically slow speed, and stall behavior. It’s good to know what the plane feels like in this regime, so that when you go out playing, you have good references. First off was to ease the stick and throttle back to achieve one knot per second deceleration while holding a constant altitude. Near 30 mph, the Superlight starts talking: you can feel the pressure on the stick, the nose wanting to hunt slightly, the rudder pedals get lighter, and you know there is some disturbed air on the tail. Adding a little power to maintain altitude, I did a 360 to the left, followed by a 360 to the right, feeling comfortable all the while. Bringing the throttle back and easing the stick on back gave a gentle nose drop. Simply going neutral on the stick provided instant flight. A little more aggressive deceleration showed a similar response: as soon as back pressure is released on the stick, the plane started flying immediately. With the addition of power, the descent rate stops and a climb can be quickly established. Great! I repeated this several times. Stalls were consistently under 30 mph. In turns, I found no tendency to drop one wing or the other – now it was a bit turbulent and not the ideal conditions for feeling subtleties, but if there was a bad habit I believe I would have detected it here.

Full power stalls were what you’d expect with the experience from the power off stalls. The nose points up pretty high, you can feel the tail getting hit with disturbed air, then the nose gently but decisively falls over forward. Again, releasing back pressure provides control authority and solid response, and I found it easy to set level flight.

Next, an exploration about the lateral axis. After establishing trimmed level flight, pulling back and releasing the stick, the nose should drop, increase speed, then the nose should rise, slowing the plane. This cycle may repeat a couple of times before settling back into trimmed flight. Then, pushing the nose over from trimmed level flight and letting go should yield a similar stability, with the nose gently pitching up, then back down, and then finding trimmed level flight. The Superlite did fine, neither slowing below stall, nor speeding near Vne, and was happy returning to normal flight.

Steep turns were like riding on a rail. Rolling in to 45 or 60 degree banks and neutralizing the controls, the plane stays at the bank angle you leave it, without wanting to roll out, or roll further into the turn. I did have to increase the bank angle on a couple of occasions, but I am sure that was the result of turbulence. Reversing 360’s were a joy with the crisp roll rate and precision with which the controls allow you to set attitude and angle!

One thing I noticed when looking out the wings is how little the wing panels bend with aileron input or pitch changes – quite a testament for the stiffness of carbon fiber.

Returning to the grass strip, I pulled the power back to see what kind of a glider the Superlight is. I averaged 300 to 400 fpm sink rate (with some thermals), flying faster than best minimum sink speed. Best L/D or glide ratio must be 8 or 10 to 1. Pretty good for open cockpit, exposed engine, uncovered fuselage. Of course, weighing in as a legal part 103 ultralight has its advantages! And still great controllability with no prop blast. It was too early in the day to work any developed thermals, darn…

Approach and landing are opportunities for more straight forward fun. The Superlite slows with no surprises. Pointed into the wind, as suggested by owner Wiebe, she three pointed solidly. It’s hard to imagine a plane so light can feel so stable. The high wing loading (compared to many ultralights) is certainly responsible for much of this comfortable feeling.

I shot a few touch and goes, then went “ultralight flying!”, low and slow. With few neighbors or cattle, and lots of fields it was easy to fly low enough that you have to pull up to go over the occasional fences or tree lines. It’s smart to carry excess speed low to the ground in case it gets too quiet… Soon I realized I was having fun instead of working, so back to the airport…..

The Superlite slips well. I have always thought ultralights with no fuselage (the Airbike, Quicksilver GT, MX series, Kolb, etc.) slip effectively because there is no fuselage (covering) to slow or inhibit the slip. The other side of this (and there always is another side) is you can muster a pretty good decent rate. Managing this is simple in Belite’s carbon wonder. The plane does not want to get away from you. You can let it, but it doesn’t want to if you are paying attention. Approaching the runway in a slip and transitioning to a one upwind wheel touch down was very accomplishable – showing plenty of control authority even at slower speeds. I held the plane there and rolled several hundred feet on one wheel before taking back off. Very impressive plane. The control surfaces request and the main gear and craft respond dutifully. After a few more patterns with several one to two to three point crosswind landings, I felt guilty that I was playing again instead of performing flight review responsibilities.

Other landing observations: Landing roll out is short ‐ partly because you’re landing so slow, the Superlite is super light, and landing on grass. Tail wheel control is certainly helped by the grass, but I feel as though the same good personality traits would be present on pavement, remembering you’re never done landing a taildragger ‘till you exit the cockpit!

Using a gps application in the iPhone to monitor, process and reconcile flight statistics is something we weren’t able to do when ultralights first came out. Push “start”, then put it in your pocket. Total flight time in this flight (flight #2 of the morning) was 42 minutes; Distance, 35.82 miles; Average speed 51 mph; Max speed 81 mph. About 16 minutes climbing and 14 minutes descending (figure that out!?) and about 10 minutes of level flight. Best climb rate 300 fpm – not bad for weighing more than a standard 170 lb pilot and a “detuned” powerplant. Great gadgetry to recall the flight by, anyway, so long as you primarily use the L.O.S. and F.T.P. (look out side and fly the plane)!

Belite is making a lot of things happen, not only in improving a great ultralight, but James is also preparing to introduce a series of very cool (and lightweight) electronic instruments. Some of the instruments will be able to just be stuck on the panel with Velcro® – airspeed, vertical speed, slip, attitude……watch the website!
This satisfying “aircraft” ultralight is available in kit form or ready to fly. Many options are available to suit budgets and preferences. As of this writing there were no formal Pilot Operators Handbook or maintenance manual, though I believe they are in the works.

2 comments:

  1. George (Wayne, PA)7:40 PM

    What a great review of a slick little airplane! Can a behemoth like me (6'4" 270#) get this little beauty in the air,fly it in "chop" and get home safely? 'Asking a lot, I know. I'm very intrigued and can't wait to see one up close.

    Good luck, folks! GBA Wayne, PA

    ReplyDelete
  2. Sounds like a great plane. How dependable is the Hurth engine? I've heard many war stories about them and have yet to find anyone who likes/trusts them.

    ReplyDelete