Since there are only four compressors but as many as 44 spheres on a given flight, the stainless steel containers have to be regularly swapped out. Once unbolted from a compressor, an air-containing sphere is stored on a nearby rack, while an empty one is attached to the compressor line, a process known as “throwing spheres.” Sometimes when the ride gets bumpy, that is exactly what happens. “I hit the ceiling once with two spheres in my hand,” Bohn says. “I thought, We hit an air pocket. Then I thought, This is not a good thing. When we bottomed out, I was on the floor.” Fortunately for Bohn, no permanent damage was done.
Depending on takeoff and estimated arrival time, technicians, SEOs, and maintainers catch some shut eye, bunking down wherever there’s space. Bunk beds are aft, and there’s that padded carpet—for insulation and noise abatement—for those who prefer to stretch out on the floor. Because of prevailing global air circulation, the WC often finds itself 20 degrees north or south of the equator, usually flying at relatively low altitudes to enable effective sampling. That often makes for a bumpy, hot ride. “Often you’ll be flying through clouds at 3,000 feet,” says Phoenix co-pilot Marc Lynch. “It’s an uneasy feeling when you can’t see the ground,” navigator Jimmie Riley says. “Tension definitely increases. You can hit some rough weather and get boxed in. You look for where the hard [thunderstorm] cells are and try to avoid them.”
Because air sampling compressors run constantly and throw off heat, temperatures inside the fuselage can blossom to equatorial levels, despite the best efforts of the aircraft’s air conditioning system. To provide temporary relief, WC pilots will often “cold soak” the aircraft by climbing up to 30,000 feet, with heaters off and crew bundled up, and direct the outside subfreezing air inside. Then it’s back down to altitude, and to business.
Once collected, air and filter samples are stored. After the WC lands—almost always at a military base—technicians, SEOs, and maintainers pitch in to off-load the samples and put them into another transport, which will fly them Stateside. “You’ve got a very perishable commodity,” says Doris Bruner, chief of the AFTAC atmospheric test branch. “Those little radioisotopes can decay quickly. You try to get into position as quickly as you can for collection and then back to the laboratory for analysis.”
Bohn, a 10-year Constant Phoenix veteran, says that once a bomb goes off somewhere on the globe, crew members can forget any scheduled weekend getaways, chores, or time with the family. For Bohn, a fervid Florida volleyballer, it might be a long time before he’s back on the beach. “It seems like [missions] usually happen on Friday afternoons before a holiday or a three-day weekend,” he says. “But as soon as the balloon goes up, we’re gone. In 30 minutes my bag is packed and I’m ready. I keep a bag for summer and I keep a bag for winter. If there’s a possibility that we’ll be seeing both hot and cold weather, I bring both.”
“It tightens everybody up when you get the call,” says Lynch. “You sit back and think What are we going to fly into? The Phoenix missions are long and they’re sudden. You go and for the next week you’re going to live in that airplane.”
The Sniffer is continuing work begun on September 16, 1947, when then General Dwight Eisenhower assigned the Air Force the responsibility for detection of atomic explosions worldwide. By the close of 1948, 55 filter-equipped RB-29 Air Weather Service aircraft were flying frequent sampling missions from Guam to the North Pole. A year later, on September 3, 1949, an RB-29 flying between Alaska and Japan detected what the entire fleet had been searching for: debris suspected to be from a Soviet atomic test. Confirmation came with 92 flights that collected 500 air samples in a two-week period. In a national radio address on September 23, President Harry Truman announced that the United States was no longer the planet’s sole possessor of nuclear weapons.
By July 1950, equipment aboard Constant Phoenix aircraft was capable of collecting air samples at altitudes ranging from 1,000 to 30,000 feet and quickly returning them to ground-based laboratories for analysis. By 1953, monitoring techniques improved with the addition of compressors and spherical containers that could hold more sampled air under higher pressure. A decade later, just prior to the signing of the Limited Test Ban Treaty, sampling reached its peak, as 77 airplanes—including B-52s and U-2s—regularly scrambled from nine airfields, covering roughly two-thirds of Northern Hemisphere airspace. By December 1965, WC-135s had taken the stage as the newest addition to the Constant Phoenix fleet. These were the aircraft flying in 1995 when both France and China conducted underground tests. Even when a nation admits to testing a nuclear device, the aircraft are sent to search for possible leaks of radioactive debris.
For crew members used to the cramped confines of earlier aircraft, the WC’s 136-foot-long, 12-foot-wide size was a relief, with plenty of walk-around space and legroom to spare. Inside, improvements to air-sampling equipment made it easier to collect evidence of fallout and to preserve it for laboratory analysis. The aircraft could operate for longer periods of time; extended-range versions capable of being refueled in flight appeared in 1968. Sampling missions were routinely conducted over the poles, the Far East, the Indian Ocean, the Bay of Bengal, and the Mediterranean Sea, as well as off the coasts of South America and Africa.
Phoenix equipment on board the WC-135 seems straight from the 1960s: consoles made of painted steel with analog gauges and dials. In fact, concedes Doris Bruner, Constant Phoenix equipment has changed very little since then: “There have not been a lot of technology improvements. We’re working at the limits of detection.”