AIR FORCE ACADEMY, Colo. (AP) -- The first woman to lead the Air Force Academy says she faced resistance and sexual harassment in her career, but competence and confidence helped her push through the ranks to one of the top jobs in the service.

Lt. Gen. Michelle Johnson said in an interview Tuesday she isn't surprised that 32 years passed between her graduation from the academy in 1981 -- in the second class to include women -- and her appointment as its first female superintendent.

"It takes 32 years to make a lieutenant general," she said referring to the experience and training it takes to reach the three-star rank required for the superintendent's job.

She became superintendent on Aug. 12 at a time the military is under increasing pressure from Congress and the president to prevent sexual assaults.

The Pentagon estimated in May that up to 26,000 military members may have been sexually assaulted last year. A series of sexual assault scandals made clear how serious the problem is, including allegations of misconduct against officers who led sexual assault prevention programs and a commander overturning a sexual assault conviction.

Johnson acknowledged she suffered sexual harassment but didn't provide specifics.

"It's not been a systematic thing," she said. Her response was along the lines of "Knock it off," she said.

Johnson brushed aside questions about whether the military as a whole is improving and whether changes proposed by Congress would help, but she said the academy is making progress.

The number of sexual assault victims at the academy who are willing to provide information to investigators and prosecutors has risen about 50 percent in the past six months, she said, although the overall numbers are small.

An academy spokesman said later that specific numbers on recent months weren't available yet.

Johnson said the academy emphasizes caring for the victims of sexual assault and teaching cadets about the broad range of sexual violations, from harassment to violent assault.

"I think we're on to something here," she said.

The academy opened its doors to women in 1976, and Johnson enrolled the next year, in "the bow wave of history," she said.

She became the school's first female Rhodes scholar and first female cadet wing commander. She played varsity basketball all four years at the academy and is the women's second-highest all-time scorer with 1,706 points.

Not everyone was happy to see women as cadets, she said.

"When I showed up, it was about change, and not everybody is happy about change," she said.

Johnson said she proved her worth at the controls of jet-powered C-141 cargo planes and KC-10 aerial fueling planes, and in her 20s, often commanded aircraft crews of men old enough to be her father.

"That opens a lot of doors," she said.

Coast Guard Rear Adm. Sandra Stosz was the first woman to lead a U.S. military academy, becoming superintendent of the Coast Guard Academy in New London, Conn., in 2011. Johnson is the first woman to be superintendent at any of the three best-known academies, Army, Navy and Air Force.

Johnson said she's grateful for the opportunity to lead the academy.

"It's kind of an amazing closure to be the superintendent of my alma mater."