WASHINGTON (AP) — The White House pick for Air Force chief of staff was confirmed by the Senate Thursday as members of Congress continued to press the service for answers about the widening sex scandal at a Texas air base.'

Sen. John Cornyn, R-Texas, ended his hold on the nomination of Gen. Mark Welsh after meeting with the nominee to discuss the scandal at Lackland Air Force Base in San Antonio, which has been roiled by accusations that instructors sexually assaulted female recruits.

"It's clear General Welsh shares my grave concerns over the situation at Lackland," Cornyn said in a statement. "General Welsh demonstrated a genuine resolve to improving Air Force-wide policies to prevent a recurrence of the grossly unacceptable conduct that took place at Lackland." Welsh was confirmed by voice vote.

President Barack Obama had tapped Welsh to replace Gen. Norton Schwartz as the head of the Air Force this month.

Among the steps Cornyn sought were a review of current Air Force policy and training on sexual assault prevention, fraternization between service members and the organization of basic military training units at Lackland, with special attention to the ratio of officers to trainees.

Lackland is where every American airman receives basic training, with about 475 instructors for approximately 35,000 airmen who graduate each year. About 1 in 5 recruits are female, while most instructors are male.

Last month, a former instructor was sentenced to 20 years in prison by a military jury after he was convicted of rape and sexual assault. Military officials said last week that the number of instructors under investigation total 15 and the number of alleged victims had increased by seven to 38.

Across the Capitol, Air Force Secretary Michael Donley; Lt. Gen. Richard Harding, who is the judge advocate general; and Maj. Gen. Leonard Patrick faced questions from members of the House Armed Services Committee about the ongoing investigation at Lackland.

"We expect the Air Force to be open and transparent with the results of its investigations. Today's briefing is a good step in that direction, but this committee expects to be fully informed as this issue evolves," the committee chairman, Rep. Howard "Buck" McKeon, R-Calif., and the top Democrat, Rep. Adam Smith of Washington state, said in a statement.

But one of the 11 members who attended the session was frustrated with the lack of information. Rep. Jackie Speier, D-Calif., said the secretary and two generals were unable to answer fundamental questions about the inquiry.

"They didn't have answers as to whether they (the women at the base) are being surveyed or interviewed. They didn't have answers as to how many investigators were handling these cases. They didn't have an answer on what the training was for these investigators, whether they were sophisticated, trained investigators or brand new on the job," Speier said in an interview after the closed session. "They didn't have any answers."

Speier said the officials repeatedly said the investigation was ongoing.

"It's not going to get fixed until these military instructors realize that their jobs are on the line," Speier said.

The Air Force later said there are 39 members of the AETC Commander's Command Directed Investigation and there are additional criminal investigations and inquiries ongoing at this time.

Rep. Nikki Tsongas, D-Mass., said she was concerned that the Air Force was narrowly interpreting the rules on a victim's access to counsel. She said lawmakers made clear that they would continue to seek answers.

"I think they heard that this is an issue that we take extraordinarily seriously," Tsongas said.