20 Sep 2010

FAQ Xenon

The Xenon concept is born in 2000…in the South of France near Orange. When playing around with the cabin (that will become a gyro), I, Raphael CELIER, was trying it flying under a parachute through innovative features like electric fly-by-wire controls, turbine (shrouded propeller) propulsion…when a customer named Guy Revol, asked to buy one of my powered parachutes. I sold one to that gentlemen, but he came back very quickly asking if i would consider to transform it into a gyroplane…Wow…I answered very honestly to him : “i don’t have experience in making such a big enclosed gyro, i only know how to build airplanes, delta trikes, paramotors. I only build from scratch a little single seat gyro flying perfectly…but a side by side…this is a big other story !” He then insisted, saying as being a former helicopter pilot from the french army in Indochina and other conflicts…he would believe in a certain new future for such a gyroplane, so he finished by: “you are a good designer with big general experience, just do it !” I replied : “i cannot afford it at the moment…” so what ! He handed me 100 000 French Francs, quite a big amount at this time (something like 20 000 Euros of today value); to proceed to make him one prototype. So did I. The first prototype barely flew, underpowered and unstable, the second slightly better and the third one was the ONE. But the initial budget was well over…So i decided to really invest on the project, hoping that one day it would really work and sell !!! So today, as per our success, i want here to thanks deeply this gentlemen from my heart, that he was right to push me, to believe in me and the project. Why the name of XENON ? I found that name in seconds, as I connected the necessary brain storming to light, light can be obtained brighter into rare gaz such as Xenon…A light was born, the Xenon was born. He got a brand new machine little time later, and due to his physical condition he donated it to the helicopter museum of Dax (South France). 3.5 years and 500 000 Euros of development, the first chapter of the Xenon was written.

2-Is the Xenon certified ?

Yes. We own many certifications. Since the very beginning of the new factory in Poland, we hired a Polytechnic engineer to revisit the whole concept, push trough stress analysis tests, made real physical stress test, stability tests, performances tests, engine tests, no one part was spared in the process. We then decided to create design / process protocols, quality control etc… just like any heavy certified airplane manufacturer. In the ultralight world, none of this is usually required, but our future projects of bigger machines do require it.
We have complied to ASTM standards, German BUT, Polish CAA…
Here is the list of countries where the Xenon is accepted today. More countries are actually working on the acceptance.
Full documentation is visible by Civil Aviation inspectors, in our offices.
France-Italy-Germany-Norway-Sweden-Finland-Poland-Australia-New Zealand-USA-Chile-Colombia-Burkina Faso-South Africa-Turkey-Checkoslovakia-Greece-

3-What kind of license to fly it

In most countries, the Xenon is classified as ultralight. Therefore an ultralight license with the gyro type rating is required. In others, gyros are classified as LSA (Light Sport Airplanes), thus an LSL (Light Sport License) is required. In some cases, gyroplanes simply fall into the general aviation category, then a PPL is necessary. Regulations vary
country to country, we recommend you to question your CAA for further details.

4-Is insurance available ?

Yes. Most countries do offer insurance, from third party to premium. Contact our local dealer or your Federation / club for further information.

5-Is the Xenon LSA ?

Yes. More precisely ELSA (Experimental Light Sport Airplanes). In 2007 and 2008, we imported factory built Xenon to the USA. Then, due to too many accidents among US production machines, the FAA decided to stop selling and importation rights for everyone, until a new construction / testing / quality control was established. It is now called the ASTM, cat.gyros. We were the first ones to apply for that, and after 1650 hours of paperwork preparation, we were able to match these very serious standards. We are part of the committee for the establishment of this standard. The FAA have accepted our Exemption, we are now waiting like the very few other ones, the final FAA release. (green light).

6-Is the Xenon available as a kit ?

No. All our models come as factory built. Due to its quite high complexity, a Xenon takes around 1000 hours to complete ; it would require really high qualifications to make it safe by private owner. We do prefer to deliver fully tested units, with guaranty. Your safety is first.

7-Hour cost of the Xenon

Considering our flag ship the Xenon RST, if you include average fuel consumption, general maintenance, basic insurance, based on 100 hours / year, hour cost is 45 Euros. Does not include original value.
Thus a Xenon is a real alternative to the helicopter, able to do 80 % of its missions.

8-How many Xenon are flying ?

We just celebrated in December 2009 our 100th Xenon, a full option version for a lucky polish customer. Already airframe #105 is built. Our safety records are today (and since 7 years of total exploitation) with 0% fatal accident, 0% injuries. A world record. Due to the exceptional quality, safety of the Xenon. Unfortunately, the gyro in general still suffer from lack of professionalism in construction and schooling seen around the world. A gyro may not be as complex as a helicopter, still it is a serious matter of construction.

9-How to order your Xenon

You are invited to our new CONFIGURATOR in this website (through SHOP menu), please fill up your data, choose your model and options, click ORDER, a mail will be sent to you back with a proforma invoice, as well to us and the general distributor of your country if available. This proforma does not engage you in any transaction until validated through a signed copy further on. You will be then contacted for further questions and to help you proceed. Payments are always done by money transfer, in 3 parts: in step one it is requested 50% deposit, an airframe number will be locked for you, 4 weeks later 25% as we will give you your engine number, balance after flight test and prior delivery.

10-Delivery time for a Xenon

We traditionally guaranty a delivery in 3 month. But most of the times your order is completed in 6 weeks. Exception is for more complex machines with heavy optional equipment, we will then confirm it.
For practical deliveries, we, at your convenience propose different services. For Europe, we are equipped with a specially built Mercedes truck able to deliver 2 machines at a time. Our drivers will take care to re-assemble the machine on arrival and go with you through a complete inspection. Our rate is 1 Euros per kilometer, one way to be paid only.
For export, airfreight is fast, safe but more expensive. As per our price list, we charge 800 Euros to dismount the machine and crate it on a special strong pallet and fully enclosed box. Best great care is taken.
By boat, we rent a container, size depending on the number of machines to fill in, we remove the rotor and machines are attached to the container floor.
A quote will be given to you at your request.

11-School on Xenon

We have several places in the world where you can get quality schooling as per our standards.
We are currently opening a school in Warsaw, with full time instructor. We do propose intensive courses, from beginner to highly advance level. We have our own runway, situated in a beautiful and peaceful area.
Contact us for program and cost.

12-Main Xenon winning features (taken from www.xenongyroplanes.com)

When Raphael Celier set out to design the Xenon he had a simple goal: make the best gyroplane possible regardless of its cost. Throughout the process if a lighter, more efficient and better option was available he would take it despite the cost or effort involved on his part. The Xenon features a Rotax engine which costs approximately $22,000 more than the used Subaru car engines found on many gyros but the Rotax is the best available. Raphael’s refusal to accept second best in any area of design, performance or construction could have led to an overpriced luxury but fortunately that did not happen.

Raphael was able to incorporate many design breakthroughs that led to cost savings. Xenon’s superior design is stronger, lighter and has far fewer parts than most gyroplanes. Fewer parts make it less costly to produce and much easier to build. While low price was never a part of the design parameters, this ease of building combined with a production factory in Poland where wage rates are lower than the US allows us to offer a superior product at a price comparable to other aircraft that do not have its many sophisticated features.

The design parameters for Xenon were:

Make a safe and stable design

Make an efficient aircraft

Make a beautifully performing and beautiful looking gyroplane

Safe and Stable
The Xenon’s aerodynamic shape and large tail surfaces contributes to its stability. The thrust line of the engine is through the machine’s overall center of gravity and is in-line with the large horizontal tail surface. The Xenon demonstrates both static and dynamic stability. It can be flown with one finger easily and even when yanking and banking its handling qualities are docile and very predictable. It has an ASTM standard compliant aircraft engine and high inertia rotor blades for an extra margin of safety. For a full discussion of gyroplane stability read “A Short Non Technical History of Gyroplane Design and Stability Considerations” after you finish this page.

An Efficient Aircraft
Weight and drag on an aircraft are the enemies. To combat them you have thrust (horsepower) and lift.

Every ounce of weight added means you need more horsepower. More horsepower means a bigger engine. A bigger engine weighs more so now you need extra horsepower just to lift the weight of the bigger engine. The designer ends up continually chasing his tail. The secret then is to keep weight down.

A major design choice is engine selection and for a gyroplane of this category by far the best engine is the Rotax 912 or its turbocharged cousin the 914. This is the largest Rotax aircraft engine available. If a gyro weighs to much for the 100 hp 912 engine the designer’s engine options are very poor. (Car engines from junkyards are the primary source for other engines). For a full explanation of this read “The Truth about Engines” after you finish this page.

A gyroplane will perform well with a 100 HP 912 engine if it is aerodynamically efficient and if its empty weight falls in the 600 lb range. If it comes out above 650 lbs you simply will not have enough performance with 2 passengers and fuel. So that is the design goal- an empty weight of approximately 600 lbs.

In addition to solving the weight vs. horsepower riddle the designer must solve the lift/drag riddle. It takes absolutely no aerodynamic training to realize that a pencil shape flies through the air better than something in the shape of a barn door. So the design goal there is to make a gyroplane that looks more like a pencil (or a rocket ship).

Clearly the Xenon looks beautiful and it is also very aerodynamically efficient. The shape of the cabin actually provides lift and the sleek design slips through the air easily. In comparing the Xenon to most other gyroplanes one immediately notices two things: the Xenon looks much more aerodynamic and the cabin tapers into a smooth cowling covering the engine. In addition to looking much better and providing all weather covering for the engine, the cowling directs clean airflow to the propeller.

In gyroplanes without engine cowlings the air becomes very turbulent as it passes the exposed engine. The air becomes “detached” from its smooth flow and so it is far less uniform when it goes through the propeller. The result is less thrust.

So Xenon’s cabin helps its performance three ways: with a lifting body, with a smooth aerodynamic shape and with a cowling that provides smooth attached air flow to the propeller.

But the cabin’s shape is only the beginning. In order to further reduce weight Raphael used an approach similar to the Cirrus and Lancair composite aircraft. The composite structure does not just provide a place to sit. It IS the aircraft frame. The engine and mast mount directly to the composite cabin thus reducing the craft weight by dozens of pounds. Built with special epoxy resins and a honeycomb core the cabin strength far exceeds the loads placed upon it.

Those breakthrough design elements would be impressive indeed but there is still more. The cabin is a total structural element with bulkheads and a full roll cage to protect the occupants. The nose of the craft is designed like a modern car which will crush on impact progressively thus protecting the passengers. The front of the gyro has the least layers of fiberglass, with thicker and thicker layers as you move aft until just in front of the pilot’s feet where there is a full structural bulkhead. The result is that in the event of hitting something the impact would be progressively absorbed by the fiberglass designed to fail right up to the pilot’s toes where the bulkhead will protect him. The structure has been crash tested at 50 kilometers per hour. The cabin has also been dropped from 1 meter with no ill effects to the occupants.

In fact the cabin is so strong it is designed with steps built into the sides so you can climb right on top of the cabin and stand up on it to check the rotors and mast head fittings during pre-flight. Don’t try that with any other gyro!

Another design element enhancing safety puts the gas tanks behind the pilot and passenger rather than having them sit on flammable fuel which so many other gyroplanes do.

Get rid of the weight
To say Raphael is fanatical about eliminating weight would be a gross understatement. In fact he can tell you the exact weight of every item on the Xenon including each nut and washer. Raphael works in grams and there are 28 grams in an ounce. When Raphael cuts 100 grams (3.5 Oz) he is ecstatic. When he cuts 200 grams the whole factory has a party. With this in mind many fittings are molded into the composite cabin eliminating the need for heavy metal backing plates. The huge keel support found on most gyros does not exist on the Xenon and yet the strength is far more than required by the loads. (Every part has been computer analyzed and materials stress tested).

Many manufacturers as they go through the design process find themselves continually adding another support bracket for this or that part of the engine or tail or trim system or muffler support or whatever. Each bracket comes with several nuts, bolts, washers, safety wires, etc. Pretty soon you have 15 lbs of unnecessary weight. Raphael refused to do this, often redesigning some elements over and over again to eliminate every gram possible. The result is that the Xenon has far fewer parts than other gyros making it easier and cheaper to build for the factory or the kit builder.

The Xenon empty weight is an amazing 244 pounds lighter than other 2 place side by side gyros! And yet it is stronger, safer, more aerodynamic and better looking!!

Performance and good looks
Performance is more than just numbers. It is how the Xenon does its job of giving you a safe, fun flying experience. The Xenon’s performance specs speak for themselves. The turbo model climbs at 1200 feet per minute with 2 people on board and can cruise at 124 mph. The unmistakable DUC propeller looks like no other prop on the market. Its unique design feathers itself in-flight to deliver maximum torque at all times, giving it similar performance to an adjustable pitch propeller without the weight, expense or complexity.

The Aircopter all aluminum blades do not suffer from the bonding problems typical of composite blades with metal inserts. Their proprietary design makes it possible for the blades to be strong and light yet still have very high inertia which provides an additional measure of safety when flying. They are both more efficient and more durable.

The cabin is soundproofed and carpeted giving an unbelievably quiet ride. Inside you can sit on ergonomically designed custom foamed heated leather seats. The cabin is 10" wider than a Cessna 172 or RAF. The occupants are separated by a padded console that features a glove compartment and full engine controls at your fingertips. The gauges are in a helicopter style center pod making them easy to read. Every Xenon comes with full flight instruments plus graphic digital engine monitoring with daylight visible full color display alerting you to all engine parameters. Behind each seat is very large luggage area that is set up to hold Xenon’s custom designed suitcase/backpacks which lock securely into place. Adjusting the seats or tipping them forward for access to the luggage takes less than 5 seconds. Additional in-flight storage is available under each seat. The overhead windows, bubble doors, wrap around cockpit glass and foot windows give unparalleled visibility. In summer you can pop the doors off in less than 10 seconds for a sportier ride.

The tail section
The twin tail booms give the Xenon a distinctive appearance but they do so much more. Using lightweight twin booms and a box construction of the tail section allows everything to be lighter and stronger. The box means every part supports every other part and it allows elimination of the very heavy steel tail structure found on many gyros. Twin booms off to each side allow the engine to sit lower and still have adequate prop clearance from the ground so the Xenon door height is only 28" making it much easier to get in and out of the gyro. Anyone from 4 and a half feet to well over 6 feet will easily step into the Xenon. You don’t have to squat down nor climb up into a gangly airframe.

But as form follows function the box tail does more. Its precise airfoil shape and large surface area provide the proper amount of stabilizing force. It is positioned in the propeller slipstream for maximum efficiency and its winglets give added stability in flight. The Xenon is a long gyro and the tail surfaces being farther from the engine gives a greater “moment arm” of leverage adding to stability. Because the vertical tail incorporates a fixed surface in front of the movable rudder Xenon avoids the “tail wagging” that occurs on tall tail gyros. Even in crosswinds the Xenon flies straight and predictably. Rudder control is through Teleflex cables. These sealed cables are 5 times more expensive than the simple wires used on most gyros but they are the very best available giving frictionless, precise, trouble free control.

Landing Gear
Xenon’s landing gear is a one piece aluminum strut. It is lighter and stronger than most other gyros and like all parts of the Xenon, it has been scientifically stressed tested to withstand far more punishment than you are likely to give it. Gyros with triangulated legs may have as many as 50 parts to make up the landing gear. Xenon has 2. Since each part adds weight and parasitic drag Xenon naturally performs better. The landing gear on the Xenon is much wider apart than most gyros which means ground handling is greatly improved. Taxiing and turning are effortless and even poor landings during student training are a non event in a Xenon. On tall gyros with the wheels close together there is always the danger of tipping over if you land on one wheel first. Xenon’s wide stance and lower center of gravity make that far less likely.

Styling like no other gyro
All gyros attract attention on the ramp but the good looks and spectacular profile of the Xenon take the “cool” factor to new heights. The Xenon’s nose looks like it could have come from a Citation Jet while inside the leather coverings, carpeting, heater, heated seats and well sealed doors make you feel like you are in a luxury car.
The original single seat gyroplanes were a great step forward for personal aviation. They provided exciting rotary wing flight at low cost and many were built in home garages with hardware store parts. Wonderful as it was to build your own aircraft for a few hundred dollars, the downside was that some of the designs were inherently unstable.

Unlike an airplane where the propeller is directly in front of the fuselage providing center line thrust, the gyroplanes had engines and propellers mounted above and behind the pilot meaning the thrust line was high and therefore constantly trying to push the nose of the aircraft down. As builders began to put bigger engines with bigger propellers on their gyros for more power they naturally moved engines higher for propeller ground clearance, which made the problem worse accentuating the inherent instability.

Finally some designers realized the problem. The solution was to lower the engine in relation to the cabin resulting in center line thrust. However, to do that they had to put long legs on the gyro so the propeller would still clear the ground. The result was some very tall gyros that you needed to climb up into but at least they were much safer as the thrust line was more centered.

Along came Two Seat Enclosed Gyroplanes
The first popular enclosed 2 place side by side gyro was the RAF. Its sexy styling made it a big hit and many kits were sold and built. Unfortunately it has a very poor safety record due to two factors. It has a high thrust line and no horizontal stabilizing surface at its tail. The high thrust line is trying to push the nose down and the lack of a horizontal tail surface makes it more susceptible to instability. Experienced RAF pilots mange their machines well but too many new pilots end up as accident statistics.

If one looks at most every flying object from a lawn dart to an arrow shot from a bow to any airplane whether it be a Piper Cub or the Space Shuttle you will see they all have some horizontal tail surface for stability. TThe RAF factory does not provide horizontal stabilizers but fortunately nearly all their customers have added custom built horizontal tails to their machines thereby providing some stability. RAF recently has come out with a horizontal stabilator on the rotor which helps trim the rotor but it does not address the inherent instability of the airframe.

Stability Modifications
In an effort to stem the horrendous accident rate of the popular RAF, the design team at Groen Brothers Aviation took time away from the design of their Hawk 4 turbine gyro to address the problem. They came up with a stability modification kit for the RAF and sold it at a very reasonable cost. There is no doubt their efforts have saved lives and they are to be congratulated.

Realizing they had a hit on their hands the folks at Groen Brothers then made further design modifications to the airframe and increased the cabin size resulting in the SparrowHawk. To enhance stability they added a horizontal tail surface and also a large vertical tail. In order to get the thrust line on center they lowered the engine in relation to the cabin. This required putting long legs on the gyro so the propeller would clear the ground. While a few pilots complained about the gangly look of the machine and the difficulty of climbing in and out, most were pleased with the machine’s stability and maneuverability. It was safe, stable and easy to fly making it a great gyroplane for training new pilots. A new Sparrowhawk II is now offered to improve on some elements of the original Sparrowhawk.

Center Line Thrust
The solution GBA had applied to RAF’s instability problem was to apply center line thrust. At this point everyone in the gyro industry in America was saying center line thrust was the answer to all the stability problems that plagued gyros.

The Europeans
Across the Atlantic in Europe several designers took a different approach to solving the same problem. Vittorio Magni in Italy and Raphael Celier in France tackled the problem with new ideas. They both wanted stability but also efficient aerodynamics and good styling. Raphael studied seaplanes which often use high mounted engines (it keeps them away from water spray) and also relied on his background of designing small drone aircraft for the French military.

Rather than adapt from the RAF cabin shape which had been a marketing success, both European designers started with a clean sheet of paper. Both also realized the key element was balancing everything on the entire aircraft not just putting the thrust line in the center of the airframe. Now cabin shape became an integral aerodynamic element as well as a matter of styling.

Cabin Aerodynamics
Magni designed and produced a beautiful and stable 2 place partially open cockpit machine where the occupants sit in tandem, one behind the other, while Raphael designed the Xenon where the pilot and passenger sit side by side in a fully enclosed cabin. Both machines have slightly high thrustlines but exhibit total stability in all areas of handling and both are beautifully styled. The sleek front of the Xenon is reminiscent of a Citation Jet.

Not only is the Xenon’s cabin contributing to stability, its shape is more aerodynamic providing less wind resistance so the machine goes faster on less horsepower. In addition the cowl over the engine compartment provides smooth airflow to the propeller. In pusher engine installations with no engine cowling the air flowing past the cabin gets disturbed when the cabin ends abruptly. This creates vortexes and eddy currents just before the air gets to the propeller making the propeller less efficient.

The Xenon’s design allows the air to flow smoothly over the cabin and back to the propeller so the propeller is more efficient allowing less horsepower to give more speed and better climb performance. Bringing things full circle, the more efficient airflow from the propeller means the tail and rudder surfaces can be smaller and lighter yet still provide the needed stabilizing force. Smaller surfaces mean less drag and less drag means better performance.

ASTM Standards
In January 2007 the ASTM gyroplane committee came up with stability standards for gyroplanes which have been adapted by the Federal Aviation Administration. The design standards specifically do not require center line thrust, what they require is stability and the standards recognize that there may be several ways to achieve that.

Magni and Xenon have all achieved aerodynamic stability which makes them safe and stable machines to fly.

Handling
In airplanes one often gives up some stability for more aerobatic handling. This concept does not translate directly to gyroplanes, as the worst gyro is still so much more maneuverable than the most aerobatic airplane. In gyros one does not really need to give up maneuverability to obtain stability.

The Magni and Xenon have a more aerodynamic shape than some gyros which may make them handle better in gusty winds. A pilot may have less work, more pleasure and higher performance flying a more aerodynamic aircraft but again all 3 are stable aircraft to fly and all 3 maneuver well.

We are proud of Raphael and of the Xenon and honestly feel it is the BEST gyroplane available today. We urge you to take a test flight and see if you agree.

13-Why the Xenon is safe !

That is an interesting question…Most of the answers can be found above in the different texts.
One big difference is that our approach was and is only professional. We did not think of the Xenon for only the ultralight category. Our team include highly skilled engineers (5 pers) to seek for perfection, safety, regardless its cost.
We use only certified materials, and our choices are taken according general well known rules of traditional aircraft construction.
But not all manufacturers do follow these simple rules…

For exemples, as seen on other machines, are some badly enginered technical solutions :
Use of INOX (Stainless Steel) for structural construction. It is well known that this metal does not hold flection / vibration. Once welded, it is a very weak metal, certainly not to be used to built rotor head – universal joints – control systems… This metal is just good for house-boats construction in non structural parts such as decorative.

Seen, electrical systems packed to fuel tanks…no comments.

Seen, fake certifications, corruption to obtain some…! Amazing…

Seen, hidden fatal crashes not reported to Civil Aviation and NTSB, how can then the safety be improved if mistakes are hidden and not corrected ?

Also found in use Teleflex for rotor control system. It is of common knowledge that Teleflex are very good to be used when there are NO cyclic vibrations such as the ones always coming from a rotor. Why ? Simply because of the construction method of Teleflexes,the end rod is simply squeezed to the inner cable. Rotors efforts/forces are well above the potential resistance with safety factor for a Teleflex. More dramatic is (also seen) installation of Teleflexes in a vertical position. It is ABSOLUTELY FORBIDEN. The lubrification will not hold long, but go down as per the gravity laws. It is guarantied to lock one day or another, with the evident consequenses, lost of control = crash.
This is simply criminal. Be aware of such non professional constructions, you life is pending on it.
This article is to open eyes, make you more aware not to buy a machine with just a shiny paint… The design and shape – configuration of the machine is not the point, but construction methods, yes. Look deep, check paperwork, company records…
All we wish is our gyro community to be safer, and avoid those terrible construction mistakes, as many accidents could have been avoided.

Instruction is also a crucial part of the job. A gyro should not be treatened like a simple toy. We must stop hear and read that gyros are the easiests machines to fly, are the safests…etc…Gyros do have a potentially higher safety than other machines, as long as they are build correctly and flown carefully. Be aware of schools proposing fix amount to get your license. Who can tell you proficiency…?? A license must be a reward for correct disciplined training under strict protocoles, not just given…and through truly experienced instructors…

Let’s mention a famous sentence: “better be on the ground dreaming to be in the air, then being in the air and hopping to get back to the ground…alive”.

14-Xenon, a winner ?

While being the elected, since 3 years, Grand Champion of all gyros, our force is our team force. We are able to develop and produce Grand design gyros, and if necessary adapt the machine to you wishes.

R.CELIER

FAQ Xenon

Frequently Asked Questions (titles are direct links)