Ever seen a radio-controlled model aircraft do 300 mph? Visit Metropolis, Missouri, this fall.
- By Ed Regis
- Air & Space magazine, September 2004
AMID THE HIGH WHINE OF TURBINES SPOOLING UP, the booming rumble of hot exhaust gases, surges of jet blast kicking up waves of sand and grass, and the sharp smell of jet fuel, a Grumman F9F-5 Panther is in the initial stages of startup. Wearing regulation Navy blue and sporting a sliding canopy and tip tanks, it is a glossy, beautiful machine, one of the best-looking on the ramp. Stenciled below the canopy is “Comdr. Lewis Patton Jr.” However, Commander Patton will not be in the cockpit, which is occupied by a pilot figurine. He will be flying the Panther from the ground at this gathering of radio-controlled jet models and their pilots.
It’s a fine Friday morning in early October, day five of Superman Jet Week at Metropolis Municipal Airport in southern Illinois. Scale-model jets have been streaking past the show tents at 200 mph and performing extreme, seemingly impossible, and otherwise deranged maneuvers since shortly after sunrise. Most of these are big machines, some almost eight feet long, with wingspans of seven feet or more. Patton’s craft (84 inches in both length and span, 34 inches tall with gear extended, and 50 pounds in gross weight) will be joining them aloft as soon as he starts the engine, a procedure that, although the specifics differ slightly, takes about the same time as is needed for a full-size jet. “About 30 seconds,” Patton says. “Introduce air, propane, then back up to air, and then it spools up to idle rpm, and once the temperature’s okay, then you’re ready to go.” He uses propane first because it ignites more readily than Jet A fuel, a type of kerosene, which he’ll switch over to at idle speed—a mere 40,000 revolutions per minute. “Max rpm is 115,500,” he says.
Patton is monitoring the engine’s performance with a clutch of instruments in a red Radio Flyer wagon. Slung underneath the wagon is an air tank used to spin up the turbine; in the wagon is a propane tank, assorted wires and tubing, a frequency scanner, an engine data terminal with digital readout, a programmer, and myriad meters, dials, quivering needles, flashing lights, buttons, and switches.
Soon the engine is emitting a fine roar and the Panther trembles with barely suppressed intensity. The turbine is now feeding from two portable tanks of Jet A, one atop each wing. At max thrust, the tiny turbine engines burn 12 to 16 ounces of fuel or more per minute—at least a beer bottle’s worth—and the internal fuel cells are so small—22 ounces each (although a given craft may hold two or three)—that the engines must draw from external tanks until just before takeoff.
Finally, Patton’s assistant, Keith Yates, who wears a blue cap bearing the Superman “S” logo, switches to internal tanks, and Patton gathers up his cigar-box-size radio transmitter, which has dual joysticks, six toggle switches, and an LCD screen. Walking behind the Panther, he taxies out for takeoff.
Runway 36-18 is a standard 4,000-foot length of black asphalt. The model takes its position on a yellow stripe, the engine spools up to an earsplitting shriek, and the F9F blasts straight down the centerline. It’s off the ground, as if shot by a catapult, in seven seconds.
Though Patton, a retired middle-school band leader from Louisville, Kentucky, has sunk $11,000 in this machine, he does not baby it around the pattern. “He’s up there doing slow rolls on top of a perfectly vertical climb,” the announcer says. (Perfectly vertical climbs are pretty much the only type of climbs here.) This is followed by a vertical dive (ditto), then a thundering low pass down the runway, followed by a vertical pullup embellished with two snap rolls. At about 200 feet, the airplane goes over on its back, drops through a two-turn inverted spin, recovers… After about six minutes of further gyrations the Panther is low on fuel, so Patton powers back, transitions to slow flight, lowers the landing gear, and, while another model lands, makes a “gear pass” down the runway to check if all three struts are fully extended. Satisfied, he makes a slow climbing turn to downwind, then sets up an approach. With full flaps and gear intensifying drag, the airplane’s glide path resembles at best a controlled plunge, but at the last moment it levels off and Patton paints the thing on so smoothly you’d swear he was in the cockpit. When he applies the brakes, you can hear the tires squeal.
The Superman jet rally kicked off in 1988, when Jerry Caudle, a pilot who also happened to be manager of the Metropolis Airport and a modeler himself, put on a flying competition for radio-controlled jets. At that time, most jet models were powered by ducted fans, miniature piston engines driving seven-blade propellers inside ducts.