Several senators are expressing outrage at a decision by an Air Force general to overturn a jury’s guilty verdict against a military pilot accused of rape, calling it a “travesty of justice.”

Sen. Claire McCaskill, D-Mo., said in a hearing Tuesday with the heads of Central Command and Special Operations Command that while she spoke, her heart was racing over the decision, which was announced Monday.

McCaskill said she believed the move would send a chill throughout the Air Force that would force women to stay silent if they are sexually assaulted.

“The military needs to understand that this could be a tipping point,” said McCaskill, a former Jackson County prosecutor and a senior member of the Senate Armed Services Committee. “I question whether, after this incident, there’s any chance a woman assaulted in that unit would ever say a word. There’s a culture issue that’s going to have to be addressed here. And what this decision did — all it did was underline and put an exclamation point behind the notion that if you are sexually assaulted in the military — good luck.”

At question is the power of the so-called convening authority under the U.S. Military Code of Justice. The term “convening authority” is used in United States military law to refer to a commander’s job, which includes appointing officers to play a role in a court-martial or similar military tribunal or military commission.

McCaskill’s concerns were echoed in a Monday letter from Sens. Barbara Boxer., D-Calif., and Jeanne Shaheen, D-Mo., to Defense Secretary Chuck Hagel.

“Lieutenant General Craig Franklin dismissed a case against Lieutenant Colonel James Wilkerson, despite the fact that the fighter pilot had been found guilty of aggravated sexual assault, sentenced to a year in prison and dismissed from the Air Force,” they wrote. “As we understand, General Franklin has not adequately explained why he chose to overturn a guilty verdict by a jury of high-ranking military officers, allowing Lt Col Wilkerson to be reinstated in the Air Force.”

Air Force News reported that the former Aviano Air Base, Italy, inspector general convicted in November of sexual assault will return to active duty and could pin on his next rank of colonel after an unusual Feb. 26 decision to throw out the case by the commander of the 3rd Air Force.

Over the past three years, the Air Force has identified 62 Air Force recruits at Lackland Air Force Base who have been assaulted by 32 drill instructors. The cases touched off new scrutiny of military culture and an apparently permissive command structure that may have created an environment in which women were hesitant to or coerced not to come forward and report the crimes.

“I think there is a culture issue,” McCaskill said. “I don’t think one general should be able to overturn a jury. … I have a high degree of frustration.”

Boxer and Shaheen wrote that the decision was unacceptable and “raises serious concerns about the military justice system as a whole.

“It is clear that despite sweeping reforms by the Department of Defense to improve prevention, investigation and prosecution of military sexual assaults — including adding specially trained legal personnel and Victim Advocates — these efforts become irrelevant when a case of this magnitude can be thrown out at the discretion of a Convening Authority.”

Indeed, the decision comes at a time when the military has found itself dealing with more and more women reporting they have been assaulted while in the military. Military officers have stressed the need for more training in the ranks and among commanders, and stressed that the military has a zero-tolerance policy toward sexual assault. But the unexplained decision by Franklin appears to undercut that policy, according to Boxer, Shaheen and McCaskill.

“In addition, we urge you, in the strongest possible terms, to take immediate steps to restrict Convening Authorities from unilaterally dismissing military court decisions,” Boxer and Shaheen wrote to Hagel. “We also ask that you work with us as we consider additional legislative options.”

In the House, Rep. Jackie Speier, D-Calif., plans to introduce a bill this week that would prevent commanders from being able to lessen sentences or overturn convictions after a court martial. A House Armed Services Committee member, Speier will also try to attach her bill to the panel’s annual defense authorization measure.

“There is no justice in a military system that allows a general to overturn the decision of a judge or jury in a court martial. Generals are not above the law,” Speier said in an emailed statement. “The reason why rape victims in the military do not report the crimes is precisely for this reason — they think the system is rigged to protect the accused.”

Under senators’ questioning, Gen. James N. Mattis, the head of U.S. Central Command, said that while he was unfamiliar with the case, he supported the current structure of the U.S. Military Code of Justice, which he pointed out the Supreme Court has upheld several times over the years.

Mattis said that the convening-authority powers were important to avoid the appearance of “kangaroo courts” convened by commanders involving their troops in which the commander is supposed to provide for the prosecution and defense.

Mattis said he has convened numerous military courts in his 41-year career, and that he has with dry eyes locked away Marines who have committed crimes. But he defended the need for absolute authority being granted to the unit commander in military law.

“I can assure you that we take this seriously; we took it seriously a long time ago,” Mattis said. “We have the authority to deal with people who act like a jerk or” behave illegally.

Carl Levin, D-Mich., chairman of the Senate Armed Services Committee, said his panel will hold a hearing on sexual assault March 13, in which he intends to make the Pentagon’s legal office aware that it will need to answer questions about convening authority.

Megan Scully contributed to this report.