Model-Airplane Buffs Aim for Transatlantic Record

Brian Handwerk
for National Geographic News
August 5, 2002
The history of transatlantic aviation could see a new milestone this
week, as an ambitious group of model-airplane makers launches an 11-
pound (4.9-kilogram) ultra-light craft on a journey from Newfoundland
to Ireland.

If successful, it would be the first Atlantic crossing by a "true" model airplane.

The craft, named Spirit of Butts Farm, will try to make the flight on only 5.5 pounds (2.5 kilograms) of fuel. While its designer, Maynard Hill, is confident of success, he acknowledges that the plane could be "drowned" in a squall or could exhaust its meager fuel supply and plunge into the sea.

After guiding the craft—named for Beecher Butts, an 88 year-old aviation enthusiast—to its cruising altitude, Hill will put the plan on autopilot and, from his safe seat in Newfoundland, anxiously await its arrival in Ireland. Pilot Paul Howey and others will be in Ireland waiting for the plane to appear on the horizon. They will head out to the bog and, if the plane comes in, take over manual control and land it. FAI officials there will be able to certify the record achievement as well.

Hill heads the Society for Technical Aeromodel Research (STAR), founded expressly to fly a small radio-controlled model plane nonstop across the Atlantic. The Newfoundland-to-Ireland feat—four years in the making—would set a new world record for straight-line distance by a radio-controlled, piston-powered model airplane.

A veteran aeromodeler, Hill is chiefly responsible for designing and developing the plane's model and engine. In more than three decades of flying model planes, he has established 23 different world records under the rules of the hobby's governing body, Federation Aeronautique Internationale (FAI).

Hill's world bests include marks for altitude (26,990 feet/8,226 meters), duration (33.67 hours), and speed in a closed circuit (167 mph/269 km/hour). "It's just been a lifetime occupation to set these records," he said, "but this one has turned out to be a really, really big challenge."

A successful flight by Spirit of Butts Farm would be the first Atlantic crossing by a "genuine model airplane," which, as specified by FAI, can weigh no more than 11 pounds (4.9 kilograms) and have an engine with no more than 10cc displacement (a measure of the volume of each engine cylinder).

A previous transatlantic crossing was made in 1998 by an unmanned aircraft launched by the Insitu Group and the University of Washington, but it weighed nearly 30 pounds (13.6 kilograms).

Design Constraints

Spirit of Butts Farm is made of balsa wood and has a 6.5-foot (1.9-meter) wingspan. Its engine is a four-stroke with 10cc's of displaced volume.

It will be launched—weather permitting—at about 8:30 p.m. August 7 off the rocky shores of St. John's, Newfoundland, where the flyers are stationed at a Royal Canadian Air Force base. The destination is Round Stone bog in Ireland.

The STAR crew said they chose the model plane's route in tribute to the first full-scale Atlantic crossing. In 1919, a Vickers Vimy World War I bomber flown by Royal Air Force pilots John Alcock and Arthur Whitten Brown made a tough landing at Round Stone after crossing the sea from Newfoundland.

After the plane is guided by remote control to a cruising altitude of 500 feet, it will be put on autopilot, to be steered by GPS signals and an onboard microprocessor. Hill said 500 feet is an optimal cruising altitude because "there won't be any airplanes that low or ships that tall, so the path should be clear."

The 11-pound weight limit made fuel capacity a big challenge. The plane's weight is evenly divided between structure and fuel. Shaving ounces off the plane's structural weight was crucial, said team member Roy Day, the former deputy director of NASA's shuttle program. "Every ounce of structure is an ounce of fuel that you cannot carry," he said.

Fuel consumption is a tricky issue. Hill must set the rate of fuel consumption by trickling a "whiskey shot," or two ounces of fuel an hour, through a small hole that can change size because of temperature or humidity. If the plane uses too much fuel per hour, the engine will run fine, but they will run out of fuel. If it uses too little, the engine can stall out, and if it does the plane will crash.

"There's been a lot of effort in modifications to the engine, the fuel system, and the carburetor to get absolutely the best efficiency out of the engine and still have it run reliably," Hill explained. "If the amount of fuel is too small the engine may quit. It's a delicate balance between using as little fuel as possible and still having a reliable engine."

The flight route, of about 1,900 miles (3,057 kilometers) total, is expected to take about 36 hours to complete, but much will depend on head winds and tailwinds.

The plane generally cruises at 42 miles per hour, but tailwinds could boost its speed to 60 mph or more. It can fly in head winds of up to 30 mph, but would burn fuel too fast to make it to the Irish coast.

Because bad weather over the North Atlantic could mean big trouble for such a small craft, Hill and his colleagues have been tracking the weather for three years to aid forecasting. "It determines when we go, and how long it will take," said Hill. "We'll watch for days when we have good weather blowing towards Ireland."

Steady Tracking

Hill and his STAR team will take four model planes with them to Newfoundland. If they are unable to track the first plane 40 hours after takeoff, they will launch the second one, followed by the others if necessary, until one of them has reached Ireland—or until all four have disappeared.

The team is confident that such a complete loss will not happen.

Software expert Joe Foster has been designing and developing the plane's autopilot and navigation systems for four years. The performance of two onboard custom-built computers is crucial to the flight's success. "If we put the right way points in there," says Hill, "and the machine and propeller keep pulling, the steering system will take it where we need it to go."

The crew will track the plane's progress across the Atlantic. "The plane has a transmitter that sends up a burst of information every minute, including its position, altitude, how fast it's traveling, engine rpm, and other control functions," said Hill.

Orbiting communications satellites will receive the information, which team members on both sides of the Atlantic will be able to access.

"Knowing the positions of the plane and its speed, we'll be able to predict it's arrival, so there should be no surprises," said Hill. "When we get to our destination it just goes into a loiter condition."

The plane will circle until the pilot in Ireland, Paul Howey, switches off the automatic system and brings the plane down manually.

On August 11, 2003, model aviation history was made when "The Spirit of Butt's Farm" became the first aeromodel to fly nonstop across the Atlantic Ocean, setting two world records in the process. Read more about it on the TAM Web site.

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