Master Sgt. Kevin Nies, superintendent of 35th Fighter Wing medical inspections, sets the scene for a mass casualty exercise at Misawa Air Base, Japan, on Monday involving a hypothecial crash of a demonstration jet at an air show. (Jennifer H. Svan / S&S)

Master Sgt. Kevin Nies, superintendent of 35th Fighter Wing medical inspections, sets the scene for a mass casualty exercise at Misawa Air Base, Japan, on Monday involving a hypothecial crash of a demonstration jet at an air show. (Jennifer H. Svan / S&S)

Staff Sgt. Amanda Bos winces as she pretends to be injured during a mass casualty exercise at Misawa Air Base, Japan, on Monday. (Jennifer H. Svan / S&S)

U.S. and Japanese medics place a “patient” on a litter during a mass casualty exercise on Monday at Misawa Air Base, Japan. (Jennifer H. Svan / S&S)

MISAWA AIR BASE, Japan — When pilots and their planes take center stage at Sunday’s Misawa Air Festival, waiting in the wings will be medical corpsmen with gurneys and gauze; firefighters, hoses and trucks; law-enforcement officers and safety planners.

Just in case.

Military officials know that an air show, mixing gravity-defying acrobatics and huge crowds, is risky business.

The base expects about 150,000 people at Sunday’s joint, bilateral air festival, put on annually by the U.S. Air Force and Japan Air Self-Defense Force at Misawa.

And every year, in the week leading up to the show, both militaries practice a mass-casualty exercise involving a hypothetical demonstration jet crash into a crowd of bystanders.

“We need to make sure we know what to do if a disaster does happen,” said Master Sgt. Kevin Nies, superintendent of 35th Fighter Wing medical inspections.

Wing inspections organized this year’s exercise on Monday involving 50 initial responders from both JASDF and the wing, as well as about 100 Japanese and American volunteer “victims.”

Some wore moulage, feigning a gouged eye, missing or burned limbs, scrapes and bruises.

As volunteers lay silently on the asphalt by Hangar 903, waiting for help, they were encouraged to play the part.

“I’ve heard better from a B-flick — let’s go, let them know you’re here” hollered one exercise evaluator, prompting an orchestra of loud shouts and moans.

The exercise was an opportunity for 35th Medical Group staffers to practice triaging patients based on injury severity, as well as transporting them to the hospital, said Col. Joe Ortega, deputy medical group commander.

“Almost by definition, a mass-casualty involves injuries that overcome resources available,” he said. “We have to get into the mode of deciding which ones need to be taken care of first.”

Security forces, meanwhile, practiced crowd control and cordoning off streets.

JASDF and the Air Force at Misawa take turns every year planning the air show mass-casualty exercise, Nies noted. “We look at previous exercise reports,” he said. “If something was done wrong, we put it in the script again.”

Last year, initial responders didn’t properly carry patients in litters.

“They did an excellent job this time,” Nies said. In one new twist this year, the exercise script called for firefighters to hose off several victims contaminated by jet fuel.

Planners also look at real-life air show crashes and lessons learned, but Nies said, “no air show crash is going to be the same.”

Come Sunday, he said, “hopefully the jet stays in the air.”