U.S. Air Force Tests Vapor Purge Times For The B-52 In The Event Of A Chemical Attack

B-52 chemical attack
A U.S. Air Force B-52 (U.S. Air Force photo by Senior Airman Jonathan E. Ramos)

Vapor purge testing provides critical information on how long it takes an aircraft operating in areas at risk of chemical attacks to purge hazardous chemical vapor and replace it with toxicologically safe, breathable air.

The Next Generation Aircrew Protection (NGAP) team recently completed rigorous vapor purge testing on the B-52H Stratofortress at Barksdale Air Force Base, Louisiana, on April 18, 2024.

This testing provides vital insights into the aircraft’s ability to clear hazardous chemical vapors and replace them with safe, breathable air, crucial for protecting aircrew during chemical events.

Prior to testing on the B-52H similar evaluations were conducted on various aircraft including the A-10 Thunderbolt II, F-15 Eagle, F-16 Fighting Falcon, F-22 Raptor, B-1B Lancer and C-130J Super Hercules.

The NGAP team is paving the way for future CBRN (Chemical Biological Radiological and Nuclear) protective gear while supporting current aircrews with valuable testing data. By analyzing purge times and vapor concentrations during flight, they determine optimal times for aircrew to safely remove protective gear post-attack, enhancing mission endurance and operational flexibility.

The concept is simple: testing allows to determine at what time during the flight, aircrews can safely remove CBRN equipment during flight, allowing the Air Force to employ its bombers in areas at risk of chemical attacks with reduced mission risk.

Capt. Kevan Thomas, 49th Test and Evaluation Squadron pilot, starts the engines on a B-52H Stratofortress in preparation for vapor purge testing at Barksdale Air Force Base, La., April 16, 2024. Following engine start up, the Next Generation Aircrew Protection team begins injecting a chemical vapor stimulant into the cabin of the jet. (U.S. Air Force Photo by Senior Airman Seth Watson)

During testing, the NGAP team injects a chemical vapor simulant into the aircraft before takeoff, monitoring concentrations throughout the flight. After landing, sensors track the remaining simulant inside the aircraft, accounting for absorption into cabin materials.

“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 in a public release. “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.

The NGAP team’s comprehensive efforts are essential for advancing aircrew protection, with data from these tests contributing to reports in the Defense Technical Information Center.

Following the successful B-52 testing, the NGAP team will continue testing on a dozen more types of aircraft.

The Next Generation Aircrew Protection team inject a chemical vapor simulant into the cabin of a B-52H Stratofortress as part of vapor purge testing at Barksdale Air Force Base, La., April 16, 2024. Sensors inside the plane continuously measure the amount of simulant in the air which is then documented by the test team. (U.S. Air Force Photo by Senior Airman Seth Watson)
About David Cenciotti
David Cenciotti is a journalist based in Rome, Italy. He is the Founder and Editor of “The Aviationist”, one of the world’s most famous and read military aviation blogs. Since 1996, he has written for major worldwide magazines, including Air Forces Monthly, Combat Aircraft, and many others, covering aviation, defense, war, industry, intelligence, crime and cyberwar. He has reported from the U.S., Europe, Australia and Syria, and flown several combat planes with different air forces. He is a former 2nd Lt. of the Italian Air Force, a private pilot and a graduate in Computer Engineering. He has written five books and contributed to many more ones.