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.