Pilots

When you first hear what Bruce Miller does for thrills, you'll think he's out of his mind. After all, flying into blossoming thunderstorm clouds is an activity that most pilots avoid. And every time he enters a towering cumulus, he's the first one to agree. But he continues to punch into them, and he's doing it for you. Bruce flies the glider Explorer for the National Center for Atmospheric Research (NCAR), helping the center to figure out how storms develop into the monsters we know and dodge.

Bruce discovered aviation in a way familiar to many of us. In 1964 he took a trip with a friend to Hole in the Rock, Utah, in a Cessna 172. "I was overwhelmed by the point of view possible from an airplane," Bruce remembers. The friend happened to be a glider CFI, and Bruce started his glider training at the Longmont, Colorado, airport.

Back then at Longmont, gliders were launched by means of a winch tow. For those who have never witnessed this feat, the glider is attached to a mile-long cable hooked to a winch mounted on a truck or trailer. The cable is reeled in at 50 mph, and the glider lifts off in a few seconds. The pilot aims for 30 to 45 degrees of nose-up pitch to gain as much altitude as the wire allows, then releases from the cable. "I would spend the weekend (out at the airport) and maybe get four or five 5-minute flights." He completed his private glider certificate in 1966, with his commercial and CFI ratings coming the next year.

In 1978, Bruce launched Cloud Base, which offers glider instruction and rental at Boulder (Colorado) Municipal Airport. He works as a CFI, designated examiner, and general handyman. He also does his share of aero-tows in a 180-horsepower Super Cub or a Cessna 180. The area is known for excellent mountain wave soaring and has an established "wave window," allowing gliders to ride the wave up into the flight levels without an ATC clearance. On a good wave day, Bruce will tow through rotor clouds to find the smooth-as-silk wave from sunrise to sunset. And once every year or two, depending on government budgets, his telephone rings with a call from NCAR.

Bruce lucked out on the Explorer pilot slot through the time-tested combination of experience and being in the right place at the right time. In 1970, he had a friend who worked for NCAR, and the center was in the process of developing a new camera setup for the Explorer that significantly changed the aerodynamics of the aircraft. The new system consisted of a black airfoil- shaped panel mounted on struts on top of the camera. Strobes were timed with a motorized 35 mm camera inside the glider. The strobes illuminated whatever dust or ice-crystal particles were between the glider and the black panel, and the camera took a photo.

The Explorer started out as a stock Schweizer 232. Bruce, at this point, had more than 1,000 hours in 232s, so his friend called on him to do the flight tests at the Denver-Jefferson County Airport (Jeffco). When the original Explorer pilot, Dutchman Vim Toutenhoofd, was unable to continue flying the research missions, Bruce took his place.

His first mission was for a Colorado State University cumulonimbus experiment in 1977. Since then, he's traveled to Montana, New Mexico, and Florida on hops with the Explorer, which NCAR makes available to various universities for data collection.

A typical flight begins on an IFR flight plan, as Bruce needs the flexibility to rise in the cloud as much as he can, into the flight levels. The glider comes equipped with two coms, a transponder, a telemetry channel for data transmission, and an open mic, so that all cockpit conversations are recorded. The Explorer flies on tow until the pilots spot an area of congested cumulus clouds: the potential thunderstorm.

Because the rope tethering the glider to the towplane is 200 feet long, the glider can't be towed into a cloud. "We wouldn't be able to see each other," notes Bruce. Flying on tow requires visual contact between the two aircraft. Instead, Bruce releases under the cloud and waits outside to see where the Explorer will need to land. ATC hands him a block of altitude, and Bruce climbs with the updrafts into the cloud, circling to stay in the strong thermals. "In a good cloud, I'll be going up at 3,000 feet per minute."

The Explorer is reinforced to withstand the stresses of flying inside a growing cumulonimbus. In fact, the glider can withstand more Gs than the pilot.

Once Bruce is committed to the cloud, he begins data collection. Lately his missions have focused on the electrification of clouds, more commonly known as lightning. The scientists at NCAR discovered that lightning depends on the presence of ice crystals in the cloud. The crystals rub together and separate, in a sense, to create an electrical charge.

And what happens when lightning does strike? "It's time to get out, mostly because of the shutdown of data transmission." Once hail gets larger than pea-sized, it's also a sign to leave the cloud.

Pilots who wish to "ride along" can catch the latest IMAX movie, Stormchasers. The filming took place in September 1994; although not an ideal time of the year for big boomers, the footage is excellent.

When asked how it feels to challenge the worst weather, he answers, "There's a time during every flight that I think, 'Why am I here?' But the next time I have a chance, I'm up there again."