AUSTIN, Texas -- The fallout from a sex scandal at Lackland Air Force Base widened Friday, when the military ousted the top commander over the basic training unit where investigators say dozens of female recruits were sexually assaulted or harassed by their male instructors.

Col. Glenn Palmer had arrived at Lackland last year and was in charge when allegations involving more than a dozen instructors began to mount within his 737th training group. Collen McGee, spokeswoman for the Lackland training wing, said it was decided the unit needed new leadership.

"But Col. Palmer did not create the environment that created the misconduct," McGee said.

Military prosecutors have investigated more than a dozen instructors at Lackland and charged six with crimes ranging from rape to adultery. Officials said Palmer was not facing any criminal charges and that his new assignment had not yet been determined.

Lackland is where every new American airman reports for eight weeks of basic training. About 35,000 airmen graduate each year, and misdeeds in the ranks of nearly 500 instructors that still are being uncovered has reverberated all the way to Washington.

The White House pick for Air Force chief of staff was held up while Congress pressed the service for answers about the widening scandal at the Texas base. U.S. Sen. John Cornyn, a Texas Republican, finally ended his hold this month on the nomination for Gen. Mark Welsh after meeting with him to discuss the scandal.

The most serious allegations involved an instructor sentenced to 20 years in prison last month after being convicted of raping one female recruit and sexually assaulting several others. Before Staff Sgt. Luis Walker was sentenced in a military courtroom at Lackland, one of his alleged victims testified the abuse left her shaken while deployed in Afghanistan and made her "a little bit more scared of everything."

About one in five recruits are female, while most instructors are male.

Removing Palmer from command was Col. Eric Axelbank, commander of the entire 37th Training Wing and who the Air Force also announced Friday would be moving on. Military officials stressed, however, that Axelbank's departure was just a normal change in command and not tied to the Lackland scandal.

As the allegations at Lackland have stacked up, victims of sexual assault in the military have pressed for congressional investigations and hearings. Among those leading the push is Jennifer Norris, a veteran who said she medically retired in 2010 and was sexually assaulted while serving in the Air Force but not at Lackland.

Norris said she couldn't pass judgment on Palmer because she didn't know his involvement. If Palmer had no knowledge of the misconduct, Norris said, she worried about the chilling effect his ouster could have on other leaders who might take his dismissal as a message that protecting their careers means covering up misconduct.

"If (Palmer) absolutely did not know what was going on with the people below him, all it's going to say to other commanders is that it's your fault and you're going down for this no matter what," said Norris, who serves as an advocacy board member of the group Protect Our Defenders.

Palmer's dismissal comes just months after the Air Force increased his profile as the allegations mounted. He invited reporters in June to a daylong tour of Lackland, offering a rare glimpse into the base's academy for military training instructors and making his top lieutenants available for questions. It was intended to show the public the Air Force had nothing to hide.

Palmer also began delivering a "neighborhood watch" speech to every new busload of recruits, telling them to immediately report sexual assaults or any hint of sexual harassment.

The first allegations began a year ago with those levied against Walker. As more trainees spoke up and the accusations became widespread, Lackland took the unusual step of halting training for an entire day in May to survey about 5,900 trainees. On a base that graduates a new class of airman every Friday for 50 of the 52 weeks in the year, Palmer called the training shut down so unprecedented he didn't even know whether it was possible.

Palmer isn't the first Lackland commander removed since the scandal unfolded. Axelbank in June relieved Col. Mike Paquette, commander of the 331st Training Squadron, for what a military attorney described as a loss of confidence in Paquette's leadership.

Lackland has about 475 military training instructors, who are the Air Force equivalent of Army drill sergeants and are assigned to turn raw recruits into airmen over the course of eight weeks. More than three dozen instructors -- including those facing criminal charges -- have been removed from Lackland in the past year, but the Air Force says the majority of those dismissals were unrelated to the sex accusations.

-- Baldor reported from Washington.