LOS ANGELES (CBSLA) – The U.S. Air Force is making history by graduating its largest class of female test pilots and engineers at Edwards Air Force Base in the Mojave Desert of Southern California.

Five women are among 24 graduates of the U.S. Air Force Test Pilot School (TPS) class of 2020, a record number.

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The rigorous, yearlong master degree’s program involves the Air Force’s top pilots — engineers and combat systems operations — working to develop and test the newest technology needed to maintain and improve aircraft flying qualities and performance.

Capts. Casey Horgan, Rachel Williams, Sarah Vorgert, Kalyn Tung and civilian Raina Duncan, also known by their call signs — Hulk, Tumble, Booster, PsiPhi and Shade respectively — are the newest female flight test pilots and engineers to graduate from TPS.

“There was never anything I was told I couldn’t or shouldn’t do,” Horgan told CNN. “I grew up with great examples of female aviators, my mom included, and all of her friends and there was no barrier there.”

The only test pilot school of the U.S. Air Force accepts about 45 of the “best and brightest” pilots and engineers per year — divided into 2 classes — from about 300 applicants. This year, about 20 percent of applicants were female, double the usual number of less than 10 percent.

“We don’t get it,” Williams said, when this year’s female graduates were asked why more women are in the cockpit and involved in aviation in general. “Because I personally haven’t experienced any barriers to getting here because of being a woman. It was something I wanted to do — so I did it. That’s where we all are so we’re really like, ‘Where’s everybody else?'”

80 women have graduated from TSP since it opened in 1944. The first, Lt. Jane Holley, was the first to attend, in 1974, as a flight test engineer. The first pilot was Capt. Jacquelyn Parker, in 1988. Two became astronauts, and one, Eileen Collins, was commander of the space shuttle Columbia in a 1999 mission.

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The Air Force Test Pilot School also welcomed its first female commandant, Col. Sebrina Pabon, in July 2020. Past TPS commandants include aviation legend Gen. Chuck Yeager, who passed away Dec. 7, 2020, and Apollo 11 astronaut Buzz Aldrin.