BARKSDALE AIR FORCE BASE, La. -- The Next Generation Aircrew Protection team finished vapor purge testing on the B-52H Stratofortress at Barksdale Air Force Base, La., on April 18, 2024.
Aircraft vapor purge testing provides critical information on how long it takes an aircraft to purge hazardous chemical vapor and replace it with toxicologically safe, breathable air.
The NGAP team's goal is to find out how well the current systems protect the crew during a chemical event.
“Ensuring that our aircraft environmental control systems effectively clear chemical vapor and maintain a safe operating environment inside the cockpit is vital,” said Kevin O’Neal, capability developer for the NGAP effort. “These tests simulate those extreme conditions to discover if aircraft systems can help protect the crew.”
According to 1st Lt. Gunnar Kral, NGAP program office lead engineer, the team starts by injecting a chemical vapor simulant into the aircraft prior to launch. Sensors inside the plane continuously measure the amount of simulant in the air. Once a target concentration is reached, the plane taxis and takes off. During flight the sensors continue to run and record as the simulant begins to clear out from the aircraft.
Following the in-flight testing phase, the NGAP team shifts focus to measure the concentration of chemical vapor simulant remaining inside the aircraft after landing.
“When the aircraft lands, the sensors that were running during the flight are replaced with new sensors to capture the concentration of chemical vapor simulant still present after engine shutoff,” explained Dr. Angela Theys, NGAP lead test method developer. “This is because the simulant inside the aircraft also soaks into the materials in the cabin.”
This process of replacing sensors ensures accurate measurement as the trapped vapors begin to re-emerge from the cabin materials into the air.
“Once the air flow through the aircraft lowers to zero after engine shut down, the vapors trapped in the materials desorb and deposit back into the air,” said Jerry Jensen, NGAP data analysis and mathematical model lead. “The new sensors capture this information and are provided for analysis along with the sensors during flight.”
Data from the tests is then analyzed and put into a report published in the Defense Technical Information Center.
“The amount of work that’s required to design, execute, and analyze the results from the test is immense,” said Rex Weinstein, Air Force CBRN Defense Systems Branch NGAP aircrew protection engineer. “None of this would be possible without the herculean efforts of the NGAP team.”
The NGAP team is managed by the Air Force CBRN Defense Systems Branch and is comprised of the Air Force Research Lab’s 711th Human Performance Wing, METSS Corp., Leidos Corp., the 46th Test Squadron, and the 28th TES.
Prior to the B-52 test event at Barksdale AFB, testing was also conducted on the six other aircraft, and will continue after the B-52 with about a dozen more.
"The amount of work that our team has accomplished and is currently doing is incredible," said Justin Spurling, 46th TS NGAP test engineer. "We look forward to continuing this testing as we work through our schedule."