Cryogenics puts the air in aircrew

  • Published
  • By Staff Sgt. Timothy Boyer
  • 60th Air Mobility Wing Public Affairs
TRAVIS AIR FORCE BASE, Calif. --  While there are many jobs at Travis that contribute to keeping planes safe and in the air, not many are more clearly tied to the mission than the 60th Logistics Readiness Squadron cryogenics shop.

"We maintain six large storage tanks that contain liquid oxygen and liquid nitrogen," said Airman 1st Class Timothy Phillips, 60th LRS cryogenics technician. "Our liquid oxygen is called Aviator's Breathing Oxygen and is used exactly how it sounds - for our aircrew and pilots to breathe while living up to the fly, fight and win mission. The liquid nitrogen is used primarily for fire suppression on our C-5 Galaxies."

Phillips said he has been fascinated by cryogenics since he learned he'd be working in it.

"We have four 5,000 gallon tanks and two 6,000 gallon tanks holding product at temperatures below minus 400 degrees Fahrenheit and they use nothing but the product itself to stay cold," he said.

Part of the cryogenic technicians' job is to maintain the cryotainers in which the liquids are stored until they can be transferred to their respective methods of delivery to the flightline.

"Liquid nitrogen on Travis is carried to the aircraft by truck, while liquid oxygen is transferred to the aircraft by trailer cart," said Staff Sgt. Paul Gomez, 60th LRS fuels cryogenic supervisor.
While the use of the Aviator's Breathing Oxygen is self-explanatory, the use for liquid nitrogen is a little more complex, Phillips said.

"Nitrogen displaces oxygen," he said. "Since oxygen is part of the fire triangle - ignition source, fuel and oxygen - it immediately puts out the fire from removing the oxygen."

Cryogenics falls under the petroleum, oils and lubricants shop in the 60th LRS.

"We are POL, but petroleum, oils and lubricants cannot come into contact with liquid oxygen," Gomez said. "The result of hydrocarbons coming into contact with liquid oxygen could be violent and potentially explosive."

The expansion rates of the liquids makes cryogenics a dangerous job in which safety is imperative, and proper maintenance of the tanks is critical.

"One cubic-foot of liquid oxygen can expand to 860 cubic feet of oxygen," Gomez said. "The results of trying to contain even a small portion of liquid oxygen, which is also shock-sensitive, in a container that is not properly designed or insulated can be disastrous."

Safety is also important due to the extremely low temperatures of the liquids, Phillips said.

"A lot of what we do in POL can become very repetitive, which can allow complacency to rear its ugly head," he said. "Any mistake on any day can lead to serious injury or death. If we skip any steps in the checklist we could end up covering ourselves with liquids that have an average temperature of minus 400 degrees Fahrenheit. Not only that, but our tanks work on a pressure system, there are no pumps, so building up pressure can be very dangerous. Liquid oxygen has the greatest expansion rate and if you're not careful that could end up blowing debris at incredible speeds or worse, blowing up a tank."

The job can be a dangerous and, at times, repetitive, but cryogenics maintainers understand the importance of their job and what would happen without their support.

"Essentially, the C-17 Globemaster III and C-5 Galaxy missions would come to a screeching halt," Phillips said. "They would have no air to breathe on the planes."