Replacing the Air Force Academy's top leadership in response to a string of rapes and sexual assaults there is only a first step toward fixing a deeply ingrained cultural problem, Air Force Secretary James Roche said Tuesday.

"We've got the patient out of intensive care. What changes do we need to make to have this become a very healthy place over the long run?" Roche said in an interview with a group of reporters. He stressed that replacing the academy's leadership was "not a one-time fix," and said it would take years, "step by step by step," to change the way women are treated at the academy.

Roche has welcomed an outside investigation into the matter. On Monday, senators scolded him for not holding academy leaders accountable.

"It is abundantly clear the secretary of the Air Force has proven himself totally incapable of handling this issue," said Sen. John McCain, R-Ariz., who called the service's response to the sexual misconduct allegations "some of the most incredible evasions of responsibility I've seen in 40 years" of military oversight.

On March 26, Roche and Air Force Chief of Staff Gen. John P. Jumper announced that they were reassigning the academy's superintendent, Lt. Gen. John D. Dallager, and its commandant, Brig. Gen. S. Taco Gilbert III, and three other senior leaders. At the same time, Roche said Dallager or Gilbert were not responsible for the academy's problems, instead blaming a climate that they inherited.

Senators were incredulous at the explanation. Sen. John Warner, R-Va., said Roche at least should have waited until two ongoing investigations by the Defense Department and Air Force inspectors general were finished before exonerating the leaders.

The Air Force is investigating how the academy dealt with 20 cases of rape and 36 cases of sexual assault reported since 1993. Cadets who say they were raped say that they were blamed and punished by their superiors and ostracized by classmates.

In the interview Tuesday, Roche said it was important to take the first step - replacing Dallager and Gilbert - before a new class of cadets arrives this summer. "A new team in place means that we can assure parents that the cadets who arrive in something like 65 or 70 days, that it's safe, (that) there are things in place to avoid this temporarily - but that's just the beginning," he said.

Roche said he remains bewildered by the sexual misconduct at the academy. He said a retired four-star general who once served as Air Force chief of staff told him Monday that female graduates of the academy who took their first assignments in the Air Force had told him they found they were treated "much more congenially" in the service than they had been at the academy.

Dallager will retire from the Air Force in June, serving out his last weeks at the Pentagon. Gilbert is also being reassigned to the Pentagon. Three other senior officers are also being reassigned.

Sen. Wayne Allard, R-Colo., said Monday the sooner Dallager is gone the better. He said the other four, although not reprimanded by the Air Force, will have to be approved for any future advancement by the Senate Armed Services Committee.

"It's going to be difficult for them to get promotions. It's flattened out their careers," he said, noting that there could be pressure to replace Roche if the committee is not satisfied with his response.

Gilbert said Monday that the Air Force was right to remove him and that he regrets statements to one cadet suggesting she was responsible for her rape.

"When you take an organization in a very different direction the easiest way that we found in the Air Force to do that is to bring in a new leadership team," Gilbert said.

Gilbert has been criticized for comments he made to the Denver weekly Westword about Lisa Ballas, a 21-year-old senior who reported being raped after drinking and playing strip poker with cadets, comparing her conduct to walking down an alley with $100 bills sticking out of a pocket. "It was never my intention to rebuke or to criticize at all. My only concern was truly for the future safety, security and well-being of cadet Lisa Ballas," Gilbert said.

Roche said there have been four reported cases of a cadet sexually assaulting another cadet at the academy during Gilbert's 18-month tenure. Three are pending and one had been disposed of.

But Allard said half of the 42 women who have come to his office in the past several months say they were assaulted within the past two years. And he cited academy surveys that showed dozens of cadets said they had been sexually assaulted.

In 1998 surveys, 22 cadets said they were sexually assaulted. There was no survey in 1999, but in 2000, 17 cadets said they had been sexually assaulted. In 2001, there were 167 cadets who reported they had been sexually assaulted, and in 2002, 56 female cadets said they had been sexually assaulted.