Thunderstorm Pilot

Arnold and Colleen arrived in Socorro on July 25, 1993 and spent the next two days looking at the SPTVAR, touring the lab, and meeting Moores’s colleagues. The trip to the lab entailed a twenty-mile drive on a paved road across the desert, followed by a seven-mile dirt road that hugged the edge of South Baldy during the climb to the top. The jarring ride and dizzying overlook left Colleen’s head spinning and she told Arnold he could take the job, but as for the road, “Never again.”

The pay wasn’t great — $100 per day plus expenses – but the job sounded a lot like his free-wheeling balloon days with Moore at General Mills. And this time, he didn’t have to worry about school or the draft interrupting his plans. Arnold took the job, but the thunderstorm season was about to end, so he didn’t start flying the SPTVAR until the summer of 1994.

From 1994 until 1998 he spent four or five weeks each summer in New Mexico, taking the spindly-looking SPTVAR up to roam through thunderstorms, searching out electricity. A typical day began around 11 a.m., when small, puffy clouds appeared over South Baldy – a signpost that a storm was building. Arnold and the researchers would head to lunch, and by the time they returned, the storm would usually have mushroomed to more than 35,000 feet.

Arnold then took off and climbed to an altitude where the temperature dropped below freezing, usually about 20,000 feet or so. Even with its big engine, the SPTVAR climbed at an anemic 500 feet per minute, taking thirty minutes or more to claw its way up to the cloud. When he arrived at the right altitude, Arnold drove the SPTVAR into the cloud and held his heading until he emerged on the other side; then he turned around and disappeared once again into the cloud until he popped back out where began.

During the two trips, ice formed on the wings and canopy, so Arnold would descend to warmer air, let the ice melt, and then climb back up and do it again. Each flight took about two hours, with perhaps a quarter of the flight inside the clouds; after five years, Arnold had spent about twenty-four hours poking around thunderstorms innards.

During one flight, he flew into an updraft and, despite pulling the throttle back to idle, the SPTVAR continued to climb. His clearance from Albuquerque Center was only up to 23,000 feet, and he watched helplessly as his altimeter shot past that altitude and the airplane kept climbing. Arnold called the controller to convey his predicament.

“Albuquerque Center, Spit-Var Eight-Seven-Five-Niner-Three.”

No answer. He waited a few seconds and tried again.

“Center, Spit-Var Eight-Seven-Five-Niner-Three.”

Still no answer. He thought, “What the heck am I doing up here?”

Then it dawned on him that he was in the middle of a thunderstorm in the middle of restricted airspace. The chance that he would collide with another airplane was close to zero.

At 26,000 feet, he finally escaped the updraft and flew back down to 20,000 feet. If the controller was concerned, he never said anything.

Despite the abundance of electricity during the thunderstorm penetrations,  Arnold was only hit by lightning three times during his five-year stint – after all, the point of the exercise was to collect data on the electrical charges in the cloud, not to get hit by lightning. A lightning strike wasn’t as dramatic as he imagined it would be – as a bright light filled the cockpit, he heard a loud bang and felt a small shock similar to the zap received from touching a cat after a stroll across a carpeted floor.

Although funding for the SPTVAR dried up in 1999, and Charlie Moore passed away in 2010, thunderstorm research continues at Langmuir with a new generation of scientists.

Back to New Mexico

In 1993, Arnold was finally ready to begin building the airplane he had designed in college. His kids were mostly done with college, Colleen’s Cub was flying, and he was officially retired, although he was still instructing at Harvey. He had also become an FAA designated pilot examiner, someone who gives check rides to other pilots.

However, his old friend Charlie Moore — his balloon partner-in-crime — had other plans for him. Charlie needed help with some thunderstorms.


The Special Purpose Test Vehicle for Atmospheric Research

The Special Purpose Test Vehicle for Atmospheric Research


Not long after Arnold had left General Mills to join the Air Force, Moore had departed to work for a company in Boston that provided consulting services to various research laboratories. In 1956, Moore and a world-renowned atmospheric scientist named Bernard Vonnegut made a visit to New Mexico to check out the state’s thunderstorms. Both men were interested in learning how thunderstorms become electrified.

New Mexico is a perfect breeding ground for the types of storms amenable to research. Thunderstorms in the Midwest and along the east coast tend to develop as part of frontal systems and the resulting thunderstorms are unpredictable, messy, fast moving, and usually accompanied by poor visibility that makes them hard to see.

Thunderstorms in New Mexico tend to be of much gentler ilk. In the summertime, individual storms build almost every day around mountain ranges due to a series of atmospheric interactions and processes that include such terms as orographic lift, condensation nuclei, adiabatic lapse rate, and supercooling. The resulting storms are much smaller than frontal storms, are spaced far apart and are easy to see due to the typical 100-mile visibility in the desert air.

Researchers prized the lightning created by these “research storms,” and they developed all sorts of methods for measuring the electrical fields inside the clouds. They attached instruments onto seemingly anything they could get their hands on to send into a cloud – unmanned balloons, military surplus rockets, and even airplanes. Moore even tried flying a balloon himself into a storm one day, but the storm spat him and his co-pilot many miles away.

By 1958, Moore and Vonnegut had tired of dragging their equipment and research materials across the country every summer and Moore suggested building an atmospheric research lab in New Mexico. The Irving Langmuir Laboratory for Atmospheric Research, named for the 1936 Nobel Laureate in chemistry, was completed in 1963. Although most funding for the lab came from the Navy’s Office of Naval Research and the National Science Foundation, the lab was owned and operated by New Mexico Tech in Socorro, located 70 miles south of Albuquerque.

The lab sits 20 miles west of Socorro at the top of South Baldy Peak, the highest peak in the Magdalena Mountains. In July and August, by 11:00 a.m. each morning, a storm develops over the peak, and researchers go to work. To prevent other aircraft from colliding with the rockets, balloons, and airplanes the scientists send into the clouds, the FAA put a restricted airspace around the laboratory – R5123 – the only restricted airspace in the United States that does not belong to the military.

In the 1970s, the lab acquired an airplane dubbed the SPTVAR, pronounced “Spit-Var,” which stands for Special Purpose Test Vehicle for Atmospheric Research. The SPTVAR had started life as an unmanned reconnaissance plane used in Vietnam. After the war, the Office of Naval Research took out the reconnaissance equipment, added a tiny cockpit for a pilot, beefed up the structure to make it safer in a thunderstorm, and loaned the plane indefinitely to New Mexico Tech. Many people described the airplane as a “powered glider” – it had the narrow fuselage and long wings of a sailplane, and a skinny landing gear that made it look like a praying mantis, but it also had a powerful 200-horsepower turbo-charged engine that could take it as high as 25,000 feet.

The SPTVAR opened up huge research opportunities for the scientists. Unlike the rockets and balloons, the airplane could loiter and fly through the storm at different altitudes and different flight paths. By the early 1990s, research pilot J. William Bullock had flown 700 hours in the airplane, with about one-tenth of that time spent inside thunderstorms. However, in 1993, Bullock retired and Moore needed a new pilot. He immediately thought of Arnold.

For more information about Langmuir Lab and thunderstorm research, visit There is also a book called “Storms Above the Desert,” by Joe Chew. The book is out of print, but you can buy used copies at Amazon. The entire text of the book is also available on the Langmuir website.

The Vari-Eze and Another World Record

The 1975 Fly-In at Oshkosh took place just a few weeks after Lesher’s world distance record, and Burt Rutan’s new Vari-Eze was the star of the show. Hearts pounded and jaws dropped as delirious pilots proclaimed, “That’s it! That’s what I’ve been waiting for!”

Pilots liked the BD-5, but the Vari-Eze had the two seats desired by many builders and was said to be capable of flying non-stop from California to Illinois for only $30 in fuel. Rutan sold plans for the airplane from his company, Rutan Aircraft Factory.

However, the Vari-Eze didn’t just show up at Oshkosh — it showed off its stuff that week with a new world record for distance over a closed course set by older brother Dick Rutan. For a closed course record, the pilot flies several circuits over a fixed set of points on the ground, landing back at the point of departure – similar to running laps around a racetrack. Dick, a major in the Air Force at the time, required two attempts to break the record – the engine blew up on the first try and he made an emergency landing in Green Bay.

Resourceful helpers back at Oshkosh scrounged a VW engine from another engine, slapped it onto the Vari-Eze, and Dick tried again two days later. This time he made it, breaking the previous closed-course record set by Lesher in his Teal by more than 83 miles. However, the absolute distance set by Lesher on July 2 still stood, and it would be another nine years before that record fell, to another Vari-Eze. In 1986, Dick Rutan, along with co-pilot Jeanna Yeager, set an even bigger record – they were the first to fly any aircraft non-stop around the world, unrefueled, in yet another of Burt’s designs, the Voyager.

In the early 1980s, a pilot named Gary Hertzler tinkered with the Vari-Eze design by redesigning the exhaust system, changing the inlet to the engine, adding a special propeller, and coating the airplane with exceptionally smooth paint. Beginning in 1982, Hertzler won an award for fuel efficiency three years in a row. Just a few weeks after his third win in June 1984, Hertzler flew non-stop from Mojave, California to Martinsburg, West Virginia, for a distance of 2,221 miles, nearly 500 miles further than the original record Arnold had planned to beat.

Click here for pictures and more information about the Vari-Eze.