TALL AFAR, Iraq -- Buzzing over this northern Iraqi city in her Kiowa scout helicopter, a .50-caliber machine gun and rockets at the ready, Capt. Sarah Piro has proved so skillful in combat missions to support U.S. ground troops that she's earned the nickname "Saint."

In recent months of fighting in Tall Afar, Piro, 26, of El Dorado Hills, Calif., has quietly sleuthed out targets, laid down suppressive fire for GIs in battle and chased insurgents through the narrow alleys of this medieval city -- maneuvering all the while to avoid being shot out of the sky. In one incident, she limped back to base in a bullet-riddled helicopter, ran to another aircraft and returned to the fight 10 minutes later.

"They call her 'Saint Piro' -- she's just that good," said her co-pilot, Chief Warrant Officer Todd Buckhouse, a 19-year Army veteran who has worked with Piro on two tours with the 3rd Armored Cavalry Regiment in Iraq.

"There was no one I wanted to hear more on a raid than her. She's a spectacular Army aviator," said Maj. Chris Kennedy, executive officer of the regiment, which is returning home this month.

Female helicopter pilots like Piro are demonstrating their valor in Iraq in one of the few direct combat roles women are officially allowed to perform in the military. Their missions often put them at risk of being hit by enemy machine-gun fire and rockets, and require them to shoot back. Piro's unit, Outlaw Troop, lost three of its eight Kiowas after insurgents shot them down over Tall Afar, and four or five others were hit by enemy fire, U.S. officers said. On Piro's first tour in Iraq, her wingman hit a wire and crashed into the Euphrates River. She and Buckhouse made an emergency landing and jumped into the water to try to save the two aviators, but they had already perished.

Despite the dangers, a growing number of women have chosen the job since the 1990s, and today about 9 percent of women in the Army are aviators. There are four female pilots in Piro's troop of 33 soldiers. "I didn't want to be a staff officer. I wanted to be an operator," said Capt. Monica Strye, 29, of San Antonio, commander of Outlaw Troop. "I wanted to have more of a combat role."

But while proving their competence in the air, female aviators say they still face obstacles from the predominantly male military on the ground. "It's far better than when my mother was in the military, but we still have a long ways to go," said Strye, whose mother was an Army nurse in Vietnam. "I know I constantly have to prove myself."

And even as the 360-degree battlefields of Iraq and Afghanistan are exposing women to combat as never before, policies excluding women from ground combat units have not been eased, but instead face increased scrutiny in Congress.

Under a law signed last month, the Defense Department must submit to Congress this year a report on the assignment of women, particularly in the Army, to ensure compliance with existing Pentagon policy, which was also codified by the law. The law requires that before opening any new positions to women, the Defense Department must tell Congress what justifies the change and observe a 30-day waiting period.

The legislation, while greatly watered down from earlier versions that would have rolled back opportunities for women, still limits the Pentagon's flexibility in adjusting to new wartime realities, critics say. It was passed over the objections of Pentagon leaders, including Army Secretary Francis Harvey, who said the change was not necessary. "We have opinions on the law, but it's now the law and we will abide by it," Harvey said in an interview last month.

Congressional critics say the change sends the wrong message to women in the military, especially the thousands now serving in Iraq. Women make up about 15 percent of the active-duty members in the military. Tens of thousands of women have served in Iraq; 48 have been killed and more than 350 wounded in action, according to Pentagon figures.

At Outlaw Troop's base outside Tall Afar, the flight line hummed with aircraft coming and going around the clock. Piro, Strye and other pilots fly demanding six- to eight-hour missions in full body armor.

In between flights, Piro and Strye explained that they prefer the Kiowa over other helicopters because it offers them a combat role, plus greater freedom to maneuver. The aircraft, which carries Hellfire and 2.75-inch rockets and has a .50-caliber machine gun, is designed to work "at the tip of the spear" with small units such as tank, Bradley Fighting Vehicle and infantry platoons. "I chose the Kiowa because it works directly with ground units in the combined arms fight," said Piro, a graduate of West Point, where she set a home run record.

The Kiowa's reconnaissance role also appeals to the pilots because it gives them more autonomy. "I have freedom to maneuver on the battlefield and I pick a target," said Strye, who flew hundreds of hours in combat with the 101st Airborne Division during the invasion of Iraq, including heavy fighting in Najaf, Karbala and Hilla. "I suppressed enemy mortar teams, called in indirect [fire] on buildings, using artillery or the Air Force to drop bombs on targets I identified."

When Outlaw Troop arrived in Tall Afar last spring, the city was an insurgent stronghold and Army helicopters were constantly threatened by antiaircraft weapons set up by former Iraqi army air defense officers, regimental commanders said. "Flying fast over the city, you were guaranteed to be hit by small-arms fire," said Strye.

One morning last summer, as dawn broke over Tall Afar's labyrinthine Sarai neighborhood, Piro and Buckhouse were watching a building for an imminent raid. They spotted lookouts on a nearby school. "You get that little tingle in the back of your neck that says something isn't right," recalled Buckhouse, of Racine, Wis.

On the ground, assaulting U.S. ground troops were ambushed from the school and began taking heavy casualties. The fire had the GIs pinned down, and medics couldn't evacuate the wounded. "Outlaw, we need a gun run south of the city," came the radio call.

With Piro at the controls, the Kiowa swooped in from the south to attack with its machine gun. The aircraft was breaking away when suddenly it was hit by a barrage of fire. "We're taking fire left," Buckhouse called out. Piro heard the popping of bullets and felt the helicopter lurch. A round had hit the fuel cell, igniting it. An alarm bell went off in the cockpit.

"We're losing fuel!" Piro said, as the Kiowa started to drop. Buckhouse thought they were about to crash when at the last minute the fuel cell sealed itself, keeping them aloft. Flying low and fast, they made it back to the base. When they landed, they saw the fuselage was split. Piro jumped out and rushed to prepare another aircraft for flight. Ten minutes later, she and Buckhouse took off for another five to six hours of combat.

"We needed to get back out there," Piro said. "We were going to save a guy's life."

Such determination has won the female aviators kudos from cavalry troops on the ground, who said they're glad to hear the women's call signs. But women still face greater scrutiny and restrictions than their male counterparts, according to both men and women in Outlaw.

Soldiers who didn't know the women would slight them over the radio, or defer to male aviators in mission briefings rather than the higher-ranking women, Buckhouse said. "If she had any emotion in her voice or even a crack, the guys [ground troops] would say, 'Say again, you're coming in soft.' No one would ever tell that to a guy," he said.

As an officer, Piro said, she walks a fine line between leading from the front and not offending male soldiers who want to pay her courtesies -- by opening doors for her, for example.

Over dinner in a noisy chow hall, Strye agreed that despite their skill as combat pilots, women face restrictions that make it challenging for them to integrate themselves in mostly male units. One rule bars female and male aviators from entering each other's quarters, while another policy requires escorts for women on base. While aimed at maintaining discipline, the segregation can be isolating, Strye said.

"If all the guys hang out and play poker in one of the guy's rooms, and I'm not allowed in there, I'll never be part of that group. I'll always be on the outside," which makes it harder to cope with the pressures of deployments, she said.

Implicit in the separation, Strye said, is a mistrust that grates on her as a professional. "You trust me to make combat decisions to defeat the enemy," she said, "but don't trust what I do when I go into another person's 'CHU,' " -- a containerized housing unit.

Back home, the sense of standing apart follows the female war veterans as they reenter American society. Strye recalls going out in Nashville after her first tour in Iraq and meeting men who didn't know how to react to her as a combat helicopter pilot. "There's an intimidation factor there. It's not what they're looking for," she said.

Piro is undecided on whether she will stay in the Army. Strye plans to get out in 2007. "I don't want it to be my entire identity. I don't want to be put on a pedestal," she said. "I just want to be Monica."