Cleaner, safer oxygen cleaning system

  • Published
  • By Staff Sgt. Robert Zoellner
  • 56th Fighter Wing Public Affairs
LUKE AIR FORCE BASE, Ariz. --  Luke has become a test bed for a cleaning system that would not only save the Air Force money and maintenance hours, but could also protect the environment, particularly the ozone.

The Oxygen Equipment Cleaning System being tested here cleans the F-16's oxygen system to include the liquid oxygen tanks and internal oxygen airflow system in the jet.

If the normal hot oxygen and nitrogen purge that Luke currently uses doesn't clean the system, the current technique is to remove the oxygen distribution tubing from the aircraft and clean each tube individually. According to Terry Caldwell, Versar Incorporated's OECS lead engineer and project manager, this is done by pouring CFC-113, which is Freon, through the tube until the Freon comes out clean. This requires considerable labor for maintainers and down time for the aircraft. Freon is a class 1 ozone depleting substance, according to Mr. Caldwell.

The OECS uses HFE-7100, a nontoxic, nonflammable, noncorrosive, nonozone depleting solvent that cleans the oxygen tubing while it remains installed in the aircraft. Thesystem can recirculate and recollect the solution and repurify it for future cleaning cycles.

"Versar's technology uses a more environmentally friendly solvent that significantly reduces solvent emissions duringcleaning," Mr. Caldwell said.

He also said that preliminary results from the cleaning of 26 F-16s showed that the oxygen systems contained a significant quantity of particulate contamination to include metal flakes, Teflon ribbon and silica. Other contaminants found were paint chips, amber resin and plant debris.

The 56th Civil Engineer Squadron Environmental Flight has also been involved in the testing to observe any benefits.

"I haven't seen enough supporting data to make an objective opinion of whether this will benefit the F-16 fleet," said Tech. Sgt. Cornelius Plumber, 56th Maintenance Group environmental manager. "However, I feel the preliminary findings are noteworthy and deserve further occupational and health analysis."

Those sentiments are echoed by Master Sgt. Alan Flynn, 56th Component Maintenance Squadron Electrical and Environmental Systems section chief, who said the results of these initial cleanings have shown some foreign matter in the filters, and although the results have not yet been compared and reported, this new process could benefit Luke and the Air Force when used for a pilot-reported physiological problem.

Questions regarding whether the contaminants found present a health risk to pilots and other crew members, a fire hazard or if they could cause equipment failure are still being looked at.

Results of the new cleaning system have not been fully analyzed to the point where the Air Force will accept the system. Versar has introduced the system to a number of aircraft to include the B-1B, F-15, C-130 and partial cleaning on a B-52. All findings will be analyzed thoroughly by Versar.

The cost of a single OECS cleaning unit is around $200,000.

"Tangible cost savings will be seen in the reduction of maintenance required for oxygen system equipment, primarily the oxygen regulators," Mr. Caldwell said.

However, he said the cost savings associated with cleaning a single aircraft that has been grounded due to oxygen system contamination requiring disassembly of the oxygen system would easily cover the expense of a cleaning unit.

Mr. Caldwell spent several months at Luke cleaning aircraft oxygen systems and collecting data. He said Luke welcomed him and made every effort to assist him.