T-tail, pusher prop and square yards of glass are strong recognition features of the Orion.

ORION Article & Photos By Dick Gavin

The first day of Oshkosh '83 a truck drove into the display area just south of the tower and disgorged a pair of big crates. Strange French words were stenciled on the side of the crates and as the crates were opened the rumor factory went to immediate warp speed. "It's a new French jet," some said. Others asked, "What's an Orion?" As Oshkosh '83 went on we kept coming back to watch the assembly progress of this obviously beautiful new mystery plane. I recognized two of the men busily at work on the Orion as ones I had visited in Houston about 20 years ago just after they had flown their tailless French Fauvel. Here now were Leonard Wolff and Gene Davidson, President and Vice President of Aerodis 56 SEPTEMBER 1985

A NEW STAR IN THE SKY

America, busily working on another French airplane. I learned that they had taken on the exclusive distribution rights for all of North America, New Zealand and Australia, and this was their number one airplane which had been flown over in an Air France 747 to Chicago and trucked up to Oshkosh. The Orion airframe there in '83 was a fiberglass shell that was assembled for display purposes for Convention goers. After Oshkosh '83 was over they took it apart and back into the crates it went for the long truck trip to Houston, where the real work began on it. While it was at Oshkosh '83 it won a host of new friends with its futuristic lines. Yes, it really did look like a sleek executive jet. Burt Rutan had conditioned EAA people that all composite pushers were here to stay, so the Orion

stirred up a storm of interest when it was learned that it would soon be available in kit form. Like the Christen Eagle, it wasn't cheap. Economic tides hadn't changed direction at that time, so many people mentally put themselves in their own Orion as they and their family toured the world at around 200 mph. '84 was a busy year for Gene and Len. In addition to their own business interests that took them to Europe fairly often, they had the time consuming task of installing all the systems in the innards of the Orion. In addition to the fuel system and its controls, there was the electrical system, the gear and flap actuation systems (both electric), the brake system, the flight control system, pitot/static system, engine indication and control system, radio installation, heating and ventilation, etc. Finally came upholstery and painting.

If all that wasn't enough to eat up weeks and months, they also had the task of preparing a very detailed construction and assembly manual in English. They did this in a progressive manner as they completed each step and they used a West Coast employee of Lockheed to do the translation for

them. I had the opportunity to go through their manual and the result of all this meticulous work is a superbly detailed step-by-step instruction manual that is very clear to understand and nearly every page has explanatory drawings. They also had to assign part numbers to the hundreds and hundreds of parts that make up a 100% complete kit — no small task in itself. By now, you can see why they didn't have the Orion in the air in two or three weeks. It was in mid '84 that the first test flight was made. Even when it looked all ready there were weeks of taxi testing, gear retraction tests, engine ground cooling tests, etc. there were the usual glitches that always bedevil a new airplane: starter problems, balky alternator, etc. In all, though, it was enough to keep the Orion from making it to Oshkosh '84, but a little over a month later it made its debut in style at the Southwest Regional Fly-in at Kerrville. As you might suspect, it was quite a hit! Sitting next to the Swearingen SX300, the spectators thought 2000 AD was here now! Since Kerrville, they've taken the Orion to Sun 'n Fun and a couple of nearby local fly-ins, where it drew ohs, ahs, and gee whizzes! In case you've forgotten the Orion's specs, it has a moderately tapered wing of 29' 6" span. The root chord of the NACA 43015 airfoil is 59" and the tip chord is 39" on the 43012 airfoil. Its wing area is 122 sq. ft. and at its all up weight of 2310 Ibs. it has a wing loading of almost 19 Ibs./sq. ft. It has room for as much as 130 gals, of fuel in the wing tanks, but normally would not carry but 58 gallons with 4 people aboard. This would give it a still air range of 932 miles at cruise speed. The wing has a 7.2 aspect ratio, a washout angle of -2 degrees, a 4.5 degree dihedral, and the angle of incidence is set at 2.5 degrees. The one piece wing is a fiberglass/ foam/fiberglass sandwich, with no internal ribs. All fuel is carried in this wing cavity. The spar is a built up composite I beam utilizing both carbon and Kevlar fibers. Obviously, their wing molds are near perfect, as the wing is as smooth as a piece of glass. The length is 22' 5" and the aircraft stands 8' 2" tall. The cabin is 96" long, measured from the rudder pedals and just under 6' long from the instrument panel. It is 44" wide at elbow height and 36" tall from seat to ceiling. Gene had no trouble fitting his 6' 5-1/2" frame into the available cabin height or leg room.

6 ft. 5'/2 in. Gene Davidson swings out of the cabin.

His knees didn't hit the panel or yoke. Front seats are adjustable fore and aft and are comfortable, even though the recline angle is a little greater than normal. The Orion gives one the impression that the front end was surgically removed from a helicopter because of its huge side windows that also function as doors. Side and down visibility is fantastic and even to the rear you have good visibility back to the 4 and 8 o'clock positions. In fact, visibility out these big picture windows is almost too good. The bottom of the window/door goes well down below your hip line and most everyone gets that same kind of nervous flutter in their innards for awhile — the same feeling you get when you peer over the edge of a tall building. The doors have simple latches at the front and rear and seem to seal fairly well in flight. You sit well back of the Lear Jet type nose and windshield, with the instrument panel occupying most of the area straight ahead. Actually, your vision in this direction is probably below average. Part of this is due to the fuselage cross sectional shape at this point being close to circular and you get the distinct impression that the windscreen is really two big "cat eyes" in front of you. Back at the pilot's head position the circular shape doesn't appreciably affect head room. Gene still had about an inch of head room left. Baggage area behind the rear seats is average in size, with 11.6 cu. ft. available. It is placarded at 66 Ibs. There is no external door, so baggage has to be loaded and unloaded over the rear seats. It uses both a dorsal and ventral fin and rudder with 14 sq. ft. of area. The upper and lower rudders are solidly in-

terconnected and have a healthy degree of travel each way. Ground handling of the Orion is very easy. One man can handle it, using the towbar, with very little effort. Since the nose wheel is full swivel, it can be maneuvered in tight places with little effort. Admittedly, it looks beautiful, like something from the year 2000, but, like me, you're wondering, "How does it fly?" We made a date to fly it before Sun 'n Fun, but bad weather put the el nixo on that. At Sun 'n Fun we made a date to fly it back in Houston under more peaceful circumstances, so when I went there for the USA '85 Exposition we took out a half day to go to Hooks Airport and see just how well this French bird did in the air ocean. We probably picked the worst time of day to fly, right at noon, with a temperature of 92 degrees and humidity around 50%. The wind was right down Hooks runway . . . 15 at 15 knots. In spite of that great big door, it isn't all that easy to get in. With Gene's height it is not much trouble for him, but a normal sized person really needs a step to get in gracefully. Gene says they are testing a couple of ideas and believes they can solve the problem, but that they had to put it pretty far down on their priority list at first. The same problem exists when exiting the airplane. Most of today's four placers are really pretty difficult to get into,

especially the low wingers, so the Orion may eventually be easier to get in and out than most. In the meantime, it's no more than a minor annoyance. The doors have a little "hot weather latch" to use while taxiing that holds them partially open for ventilation. Since there is no slipstream over the cabin, this is almost a necessity in hot weather. SPORT AVIATION 57

ORION — A NEW STAR IN THE SKY This lack of slipstream over the control surfaces means you must taxi it with brakes alone, much like a Grumman Cheetah, and until you hit 40-45 mph the rudder control is zilch. The airplane has a solid feel taxiing. The seats are a little on the firm side, so the main gear feels a little stiff as you cross pavement joints. The nose gear, though, is well above average in springing. With the engine placed amidship you aren't as likely to brutalize the nose gear as you are with a tractor installation. Although instruments aren't arranged in the standard airline T grouping, they were so placed that the airplane could be flown IFR without excessive scan effort. In the top center of the panel was a neat little combination switch and annunciator panel that showed the current state or activation of various items. When a switch was pushed, a light in the switch would go on. Other lights were primarily warning lights. They also have a console between the pilots where all engine, gear and flap controls are located quite conveniently. Gear actuation is via a 2" long switch handle with a wheel on the end. Green gear lights and yellow transit lights are next to the gear "handle". Flap switch is a spring loaded paddle switch, with flap position checked by actually looking at the flap. The throttle is a rather large T handle. Provision is made for a prop pitch control for future installation. Starting procedures for the carbureted Lycoming O-360 (180 hp) are standard. I did notice there was practically no engine shake on starting and initial acceleration. The Orion uses almost the same Dodge clutch and shafting system Molt Taylor uses on his pushers. Basically, it's a pair of closely spaced wavy plates with tiny steel balls between them. The solidity of the connection between the plates responds to whatever forces are generated by the engine or prop and shaft, serving to protect against destructive resonance in a long shaft. The system actually makes for a considerably smoother engine/ prop installation, as the stress lash between power and compression strokes is leveled out. Engine run up is simple. Static rpm was only 2050 with this fixed pitch, ground adjustable prop that is pitched closer to cruise performance than T/O or climb. A constant speed German MT prop is being shipped to them and it is 58 SEPTEMBER 1985

The Orion's panel.

only 6 Ibs. heavier. It will be a welcome addition to the Orion, as at its present 2100 rpm for takeoff and climb, Gene says the engine is only developing 135140 hp. There is no problem cooling the buried O-360 as it utilizes a shrouded fan to augment ram air like a helicopter. I never saw the CHT over 360 degrees or EGT in excess of 1300 (except on T/O). Any airplane without the ability to vary prop pitch is going to suffer and the Orion is no different. The figures we quote for IAS and rate of climb don't really tell us very much about its potential performance, so don't cast these figures in concrete in your memory. Wait until we can fly the airplane with the constant speed prop and then the numbers will really mean something. The German built three-blade MT prop is made by a firm that has a number of former employees of the famous Hoffman Prop Company. It is a wood prop with an epoxy cover and metal tipped leading edge. The 61" diameter is limited by the overhanging stabilizer/ elevator so multiple blades are called for. The ventral fin and rudder also act as a skeg, protecting the prop against over rotation on takeoff or landing. The last thing we did prior to run-up was to close and lock the doors, using two latches per door. With doors closed, the noise level drop was significant. Acceleration on takeoff doesn't slam you back in your seat, but considering the fact that the engine was 600 rpm shy of its rated 2700 rpm, it wasn't bad. Gentle rotation was begun at 60-65 knots and the angle held until it flew off at 80 knots. The gear was retracted as we accelerated to 100 knots and the rate of climb was showing 500 ft./min.

at this point. Climb speed was increased to 120 knots and rate of climb also increased to 800 ft./min. The air in the climb was moderately choppy and it was in this initial climb phase that the Orion exhibited a considerable Dutch roll tendency, much like a large swept wing jet might do with the yaw damper off. The root causes are not simplistic, but basically it usually is caused by too short a fuselage and too little fin area, in combination with a large wetted area forward of the wing. This might fit the Orion, too, although this hasn't been verified by analysis. Dihedral, wing shape, root fairings, CG location, etc. are also factors. A popular factory built airplane also suffers from this deficiency, so this aircraft isn't the only one by far. In any case it requires the pilot to almost instantaneously feed in opposite rudder to stop it. If a pilot's coordination is lazy and he tries to correct it by opposite aileron alone he invariably will aggravate the roll, as it requires a fine degree of anticipation. A yaw damper is the usual solution to Dutch roll, as it senses yaw before most pilots would and feeds in tiny amounts of rudder quickly. At cruise the Orion has superb directional stability, being practically dead beat. This seems to say that the vertical tail is correctly sized for higher airspeed, but possibly undersized for low speed. Actually, in cruise I found Orion to be a delight to fly and so stable that it probably doesn't even need an autopilot. Control pressures are moderately light and very well balanced. Pitch stability is quite good. Displace the nose up or down a few degrees, release the yoke and it will return to trim speed in slightly

power back to idle and the rpm gets in the 1500-1800 range, the prop and shaft are going through a de-coupling phase and a significant resonant vibration is momentarily felt. I didn't feel it when power was cut on landing, so apparently it only occurs when there is a considerable air load on the prop at higher speeds. The G-802 Orion is an outgrowth of the G-801 that was designed and built by Jean Grinvalds. Six years and 7500 hours of work went into the G-801 prototype, which first flew in 1981. Currently there are over 30 G-801's under construction in Europe. When the decision was made to offer the G-801 in kit form several design improvements were incorporated in the G-802 Orion. The cabin was widened 2", the fuselage lengthened 5", the ventral fin was increased in size and an improved wing/ fuselage fairing installed. Gene told me they now have their U. S. dealership organization nearly complete and several of the dealers have Even looking out to the side, the helicopter-like visibility is startlingly apparent. their Orions well along in construction. A production run of 90 G-802's has alover one long oscillation of 8-10 secshaker to alert the pilot. With these ready begun in France, so it seems onds duration. thoughts in mind, we could see no real likely that we will soon see G-802's apvalue in doing a stall series investigaIn 45 degree banks, the Orion shows pearing on three continents in ever intion. Like any high performance little tendency to tuck the nose or lose creasing numbers. A well known deairplane, you simply don't let it slow up speed rapidly, indicating the span loadsigner and builder in Texas reportedly to where you are in danger of an acciing isn't excessive. This is an important is close to completion on his and will dental stall. point at the lower airspeeds in a pattern, probably be the first to fly a kit built I hesitate to quote performance numwhere steep turns might be required at Orion in the U. S. bers vs. rpm as they will have little value times. We will be looking forward to acceptin assessing the Orion's performance The trim tab itself is extremely sensiing Gene's kind invitation to again fly capability until we can crank in manifold tive, but from our takeoff setting to levelthe Orion after they have made the conpressure and rpm with the constant ing out in cruise took only a tiny adjuststant speed MT prop installation. All in ment. Also, when slowing from cruise speed prop, but here are a few numbers. all, I was well pleased with the way it At 5000' msl, 82 degrees F., we indispeed to 80 knots, the yoke didn't heavy flew, its comfort, its construction feacated 142 knots (164 mph), which tures and, of course, its looks. up excessively and I didn't need to would true out in the 175 mph range. change the trim setting at all for comOur rpm was 2450. With the constant fortable flying. speed prop it should meet its advertised The airplane has good roll response cruise of 186 mph at 75% power. Noise through its normal speed range. We level is somewhat below average, with didn't stall it, but flying at 80 knots, both clean and with approved flap, it felt solid conversation in normal tones possible. and was at least average in control reTurning 2300 rpm, with 10 degrees sponse. As we descended back into the flap and 90 KIAS, we showed a descent rate of only 200-300 ft./min. As the gear low level chop, we found the Dutch roll tendency was less noticeable, although and landing flaps were extended at 100 still there. It improved even more with KIAS our descent was a most normal gear extension and with full flaps it was 700-800 ft./min. Coming over the fence at 80 knots we got some float, with scarcely noticed. There is no pre-stall buffet in T-tail touchdown coming very smoothly at 65 aircraft, so they must rely on mechaniknots. cal or electrical stall warning. The At present, the Orion uses a French Orion's is electric. T-tail birds are also tire and wheel, slightly larger than the more susceptible to the deep stall 5.00 x 5 Cleveland wheels that will soon phenomenon, in which the aircraft may be installed. This will give some extra descend almost vertically at fantastic badly needed room in the wheel well. rates. The prototype BAC-111 was lost Gear operation uses two separate elecin a deep stall qualification test begintric motors and worm drives for both exning at 20,000 feet. The flight recorder tension and retraction. An emergency showed a descent rate of 10,000 ft./min. crank in the cabin allows manual gear and no flight control application or extension with electrical power loss, power change of any effect whatsoever! with motors automatically declutching in the "fix" was a "stick pusher" that took such cases. Gear track is 99" and wheel elevator control away from the pilot and base is 91". This show down the inside of the Orion's radically lowered the angle of attack. In flight, engine vibration seems to be tailcone shows the prop shaft, wood bulkOther such aircraft rely on a stick less than average. When bringing heads and F Glass ring bulkheads. SPORT AVIATION 59