In getting serious about this, let's first look at where one should put strobes. Certified airplanes usually have a rotating beacon on top of the rudder, but that is not visible from below so a strobe is often placed on the belly as well. These are turned on during the day. At dusk the navigation lights are turned on along with the anticollision lights.

We should install our anticollision lights so at least one light can be seen from any direction. If strobes are placed in the outer edge of the wing tips, that goal can be met with only two lights. Of course the other alternative is to place the lights above and below as on certified airplanes, but if that doesn't satisfy your concern you can do both.

Flashing lights of any type have to be a safety benefit. Tests that I have evaluated indicate that a pulsing quartz halogen light is more visible in bright daylight than a strobe. The best pulse appears to be about 1 second on and 1 second off in duration. Strobes appear to work best at night but we don't have to concern ourselves about that because ultralights aren't permitted to fly at night. Ultralight flight is permitted 30 minutes before official sunrise and 30 minutes after official sunset, provided the ultralight has anticollision lights.

One problem with these types of lights is the likelihood of radio frequency interference (RFI) - the result of the pulsed power that surges to the lamp or strobe. The pulse is in the form of a square wave incorporating some very high frequency components that can be picked up by the antenna on your transceiver. You will be subjected to a pop in your headset each time the light flashes on. The interference is easily avoided if some simple precautions are followed.

The circuit to your lights or lamps should not depend upon the airframe for its ground connection. The lights must be wired all the way from the pulse source to the lamp or strobe. There is no need to purchase some super coax cable for this purpose. Regular well-insulated tinned copper wire will do very well.

The trick in eliminating RFI is to twist the wires together. The amount of twisting is important. Ideally the wires should be twisted so there is about one twist per inch. This reduces the power of noise radiated as RFI by 10,000 at 100 Megahertz, and that is a lot of shielding. Higher frequency components of the pulse are attenuated even more. As compared to the noise from your ignition, it is essentially zero interference.

Now we come to our next subject - ignition noise.

This problem is eliminated on certified aircraft by shielding the ignition wires with metal braiding, and then grounding the braid. That may or may not work on your ultralight. I made up a set of shielded wires for my engine and found I couldn't fire the spark plugs. My engine is fired by a capacitance discharge ignition (CDI) system, which produces one pulse with high frequency components in its wave. The shielding, in conjunction with the wire insulation and the wire going to the spark plug, formed a capacitor. The capacitance, though small, shorted out the pulse to ground. This I found out a good deal later from an electrical engineer, who was versed in that sort of thing.

I had to find an alternative means of cutting down the fierce spark noise in my radio. I didn't want to use resistance wire because it has a way of deteriorating with use. Most resistance wire uses a nylon string that has been loaded with graphite as its current conductor. In time the spark current causes the graphite to sublimate (evaporate away), the resistance goes up and the engine will start to miss, especially at high power settings. Not good.

I tried various noise-suppression caps and finally I found one that would do the job satisfactorily. Of course it was the most expensive one so it is no wonder. The best cap I was able to find is a Bosch, part number 356-351-032 marked as having a 1K-ohm impedance. To be sure it doesn't cut out all of the spark noise but by turning up the squelch on my transceiver, it works just fine. The only time I hear any spark noise is when I have an incoming signal, but it is at an acceptable level.

If there is anything better out there I would like to hear about it.

In looking at the shelves of your local auto parts store, you can find a number of oil and gasoline additives. The oil additives with which I am familiar either make the engine oil have a higher viscosity or have some solvent property intended to clean up varnishes in the engine. When I purchased my first new car many years ago, the service manager tried to sell me an additive. He said that after a quart of the additive was added to the oil, they would run the engine for an hour, then drain all of the oil and drive the car 100 miles after which it would run perfectly fine.

I had just graduated from college and had studied engine design in addition to spending considerable time in the engine laboratory. I wanted to ask the critical question: Did they disassemble the engine and inspect it for wear or damage? Also, did they prepare an engineering report describing the test signed by the person in charge of the test?

I let it pass because whenever I've asked one of these suppliers of oil additives for an engineering report on tests run in a laboratory under controlled conditions, the results are disappointing.

The conclusion of all this is, don't deviate from what your engine manufacturer recommends. There is little doubt in my mind that in 4-stroke engines the new synthetic oils are superior to the basic petroleum oils. But my advice still remains, follow your engine manufacturer's recommendations. When it comes to 2-stroke oil, I am convinced synthetic oil is the only way to go. I don't believe any 2-stroke engine manufacturer recommends anything but synthetic 2-stroke oil. It burns cleaner and provides better lubrication at high temperatures and does not require a large quantity per gallon.

Oil in gasoline displaces fuel and burns slowly so it does not provide significant energy to the piston. Before the development of synthetic oils, early 2-stroke motorcycle racers would reduce the amount of oil in the gasoline and the result was more power. One regional champion told me that he ultimately went to 100:1 in his fuel-oil ratio and would win races. In the process, he sacrificed the engine but he would win races. The motorcycle manufacturer sponsored him so the ruined engine was no great loss. He would also do such things as use only one ring on each piston.

What I'm leading up to is this: Whatever you add to your gasoline it is very likely going to reduce the amount of power available to your engine's output. Yes, even alcohol reduces available power. Alcohol has a lower energy content than gasoline.

The question of fuel stabilizers comes up from time to time. For boats or power generators that sit for long periods of time between uses, the manufacturer often recommends a stabilizer. But your ultralight shouldn't have this problem. Every time I fly I usually burn more than half of the fuel in the tank so I am always adding fresh fuel. When winter comes and I quit flying, I drain the remaining fuel and put it in my old truck that doesn't require any special consideration. Of course, I do one more thing. With the fuel line disconnected I run the carburetors dry.

As a final note, if FAA hasn't approved an additive for certified aircraft, then it probably should not be considered acceptable for your ultralight.

Arnold C. Anderson has been flying ultralights since 1982, logging more than 300 hours in his Kasperwing. After 37 years in the engine and aerospace industry as a mechanical engineer, designing electro-mechanical equipment and solving reliability problems in equipment for unmanned deep space missions, Arnold is now retired. He lives in Bellevue, Washington, where he pursues his hobbies, including aerial photography and flying RC airplanes and gliders.

This Bellaire SE was first introduced in April '97 and now reportedly has 220-plus hours of flying time. Co-owned by Arnold Gilmore and Richard Berstling (who assisted Gilmore in building the single-seat aircraft), the Bellaire SE is marketed by Berstling's Bellaire Monoplane Company, which expects to add 2-seat siblings (both side-by-side and tandem seating versions) to its hangar in the near future.

Bellaire designer Richard Berstling recently flew 13 1/2 hours from Florida to Wisconsin in his (and co-owner Arnold Gilmore's) beautifully finished Bellaire SE. Berstling assisted Gilmore in building the original Bellaire SE, a plans-built aircraft first introduced in April '97. The plane Berstling flew currently has a little more than 220 hours on it.

Powered by a 50-hp Rotax 503 dual carb 2-cycle aircraft engine using a 2.58-to-1 reduction drive, the Bellaire cruises at between 85 and 90 mph. When the Rotax B gearbox is changed to a Rotax C drive (with a 3-to-1 ratio), cruise increases to 105 mph.

Climb rate is listed at more than 1,000 feet per minute, with power-on stall speed coming in at 25 mph (power-off stall is 34 indicated), according to Berstling. Standard stick and rudder controls are used with a center stick and left throttle. When built from plans, the plane will take about 2,000 hours to complete, according to the Bellaire Monoplane Company. Component parts are also offered to cut down on building times. The plans consist of 12 pages of 24- x 36-inch CAD drawings.

According to Berstling, the plane will soon be available in a 2-place configuration (both side-by-side and tandem seating versions). Currently three 2-place craft are under construction with completion expected in about 6 months' time. These will be powered by the Rotax 912 series of 4-stroke engines, as well as the 75-hp Walter Micron 4-cycle engine.

- Report filed by Dave Loveman

Single-Cylinder 25-Horse Engine With Powerfin Prop

Above: Earthstar Aircraft has a new engine/propeller combination to offer buyers of their latest Thunder Gull ultralight, the Gull 2000. Right: The 25-hp single-cylinder Hirth F-33 2-cycle engine and Powerfin E Model 3-blade composite prop produces a smoothness "uncharacteristic of a single-cylinder engine," Earthstar claims. The empty weight of the Gull 2000 with this engine/prop combination is only 236 pounds (well under FAR Part 103's 254-pound limit for single-seat U.S. ultralights), according to Earthstar.

Earthstar Aircraft, manufacturer of the Thunder Gull line of single-seat ultralights and 2-seat ultralight trainers and light sport aircraft, is offering a new engine/prop combination on their Thunder Gull 2000* single-seat ultralight. The Gull 2000 features a 4130 chromoly steel fuselage mated to an aluminum wing and tail section.

"Testing has been completed on the Gull 2000 ultralight with the 25-hp Hirth F-33 [single-cylinder 2-cycle] aircraft engine and the Powerfin E Model 3-blade composite propeller," the company reports.

Earlier this year, Earthstar was testing the single-cylinder 26-hp Zanzottera MZ 34 2-cycle engine, which "had a wide power band and good performance, but had a lot of vibration," says Earthstar president and Thunder Gull designer Mark Beierle. Since then, Beierle has installed the Hirth F-33 and the Powerfin prop. "This combination flies the Gull 2000 quite well, with very little vibration," Beierle claims. He has about 35 hours on the engine, belt drive and prop combination and indicates it performs very similarly to a single-cylinder 26-hp Rotax 277 2-cycle engine, "but a lot smoother, and with phenomenal fuel economy." Using the F-33 engine and Powerfin propeller, "the Gull 2000 can fly along at cruise speed with as little as 3,800 rpm," Beierle says.

"The smoothness of [the Hirth F-33 and Powerfin prop] combination is uncharacteristic of a single-cylinder engine," Earthstar notes.

Significantly for ultralighters flying under the provisions of Federal Aviation Regulation Part 103, the new engine and prop reduce the total empty weight of the Gull 2000 to 236 pounds, well under the 254-pound maximum empty weight requirement for Part 103 single-seat ultralights in the United States.

"It gives the kind of performance I am used to, but with very little weight," says Beierle. The Gull 2000's 236-pound empty weight allows pilots to add additional instruments, navigation or communication equipment (like a GPS unit or aircraft transceiver) or other systems, and still stay under the Part 103 weight limit.

Report filed by Dave Loveman with Buzz Chalmers * See "UF! Pilot's Report: Single-Seat Gull 2000 - Excellent as Always," January '01 Ultralight Flying! magazine.

Your Choice: Motorcycle or Powered Parachute

Ultralights have sometimes been described as the "motorcycles of the air," which the new Flite Bike really is, combining a Honda Reflex motorcycle with a Buckeye powered parachute.

If you were to survey a number of ultralight pilots for some of their hobbies and backgrounds, you would probably find that some form of "motorcycle" has been or still is part of their lives. Well, a Virginia company called Flite Bike has come up with a different and totally unique concept - a Buckeye powered parachute built around a Honda Reflex motorcycle, claimed to be "the world's first roadable powered parachute."

The Flite Bike, as a "motorcycle," cruises comfortably down the highway at 45 to 50 mph. When used as a bike, it drives like a "trike" - that is, it has outriggers and air shocks on each side that operate off a compressor. Thus, you have your two main motorcycle wheels on the pavement plus the two wheels on the outriggers for added stability.

When used as a powered parachute, the air shocks are inflated, raising the rear motorcycle wheel off the ground, with the weight then being transferred to the outriggers, which extend outward for additional stability.

Steering on the ground and in the air is done by using the handlebars. On the road, the standard throttle and braking system are used on the bike; in the air, the throttle is operated by a lever on the side of the bike (similar to that used on the Buckeye powered parachute). The unit uses a standard Buckeye powered parachute canopy, which is capable of carrying the 550-pound Flite Bike assembly and a 250-pound pilot with fuel for 2 1/2 hours of flight time.

You purchase the unit in two parts. First, you buy the motorcycle from your local Honda dealer, then you get the Flite Bike installation package. The kit is to be built by Buckeye and installed only by authorized Buckeye dealers, with installation taking about 1 day.

Flite Bike touts one obvious advantage of this hybrid design concept: "Caught aloft in bad weather?" the company asks. "No problem. Land and travel by road to your destination."

Price for the Flite Bike kit (custom Flite Bike airframe, ram-air powered parachute canopy wing, 65-hp Rotax 582 liqiuid-cooled 2-cycle aircraft engine and 4-blade composite prop) is $19,800. The Flite Bike kit is "specifically designed for the Honda Reflex motorcycle and cannot be installed on any other motorcycle," Flite Bike says. (Manufacturer's suggested retail price for the Honda Reflex motorcycle is $4,995.)

- Report filed by Dave Loveman

4-Cylinder, 4-Stroke, Just 63 Pounds

This military surplus Teledyne 4-stroke overhead-valve engine puts out 18 to 20 horsepower and weighs just 63 pounds. With a little reworking of the heads and a larger carburetor, the engine can generate more than 30 horsepower, according to David Vogel of Vogel's Electro Source. Vogel indicates parts for the engine are still readily available.

What's old is new again. For years, ultralight pilots and manufacturers have been looking for a light, reliable, economical 4-stroke engine, in the 25- to 35-horsepower range. Well, it seems the U.S. government has had one sitting on their military surplus shelves for years.

A company called Vogel's Electro Source in Milford, New Hampshire displayed the surplus engine (said to be manufactured in the early '90s) to the aviation industry recently. The little 4-cylinder 4-stroke engine has a dry empty weight of 63 pounds. The 32-cubic-inch (524-cc) displacement engines are military standard model #4A032-4. They come complete with electronic radio frequency suppression, waterproof ignition and shielded spark plugs, and put out about 18 to 20 horsepower with the standard carburetor.

"Our dyno tests have shown these stock engines to be in the 18- to 20-hp range," Vogel's Electro Source says. "We will offer affordable plans and kits to safely increase power to 40 horsepower." And although the displayed engine weighed in at 63 pounds, according to Vogel's, "further weight reduction is possible," the company claims.

But according to David Vogel of Vogel's Electro Source, with just a little reworking of the heads and a larger carburetor, the engine can reach more than 30 horsepower. When fired up on the "test stand" (two blocks of wood bolted to the bottom of the engine), the engine ran like a top. In fact, even with no rubber mounts at all and revving up to nearly 5,000 rpm, the engine didn't move.

Parts are still readily available for the engine, according to Vogel. A new head (complete) sells for $75, and you can reportedly rebuild the complete bottom end - rings, pistons and connecting rods - for $120.

The "new-in-the-crate" engines "include fuel pump, standard spin-on oil filter, full documentation and technical service manuals," Vogel's Electro Source says. The company was offering a special on the engine, including a prop hub, prop and engine accessories for $1,295. ("By the way, the government paid $2,400 [each] for these engines," Vogel's Electro Source claims.)

- Report filed by Dave Loveman