Coalition warplanes pounded targets in Baghdad Friday night and early Saturday, dropping laser-guided bombs on tanks, artillery and Republican Guard buildings in the Iraqi capital and near the airport.
In the past two days, pilots have reported seeing heavy fighting between U.S. and Iraqi forces in the city and the heaviest anti-aircraft and surface-to-air missile fire since the war started March 20.
Pilots say the air over Baghdad has also become congested with coalition planes and they are more worried about crashing into one another than about being hit by Baghdad's air defenses, which they can generally see in advance and avoid.
"There's a lot of airplanes up there at the moment. You have to keep your eyeballs out for the other guys," said Lt. Cmdr. John Enfield, an F/A-18 Hornet pilot aboard the carrier USS Kitty Hawk in the Persian Gulf.
"That ends up being one of your major time consumers, just making sure you are safe from all the other airplanes."
Allied warplanes on Saturday began flying missions over the Iraqi capital specifically designed to prepare for any future U.S. ground attack on downtown Baghdad, the U.S. Air Force general in charge of the air war said.
Lt. Gen. Michael Moseley, speaking from his command post in Saudi Arabia, told reporters at the Pentagon that he hoped that the Iraqi regime would surrender before urban warfare became necessary.
Controllers are "stacking" the supersonic warplanes at different altitudes to reduce the risk of mid-air collisions. No such accident has been reported near Baghdad so far, but three British soldiers were killed last month when two Royal Navy Sea King helicopters collided over the northern Gulf.
"As the ring tightens and the Marines and the Army come closer and closer to the center of Baghdad, the front lines get smaller and smaller," said Lt. Cmdr. Mark Johnson, another F/A-18 pilot.
"There's the same number of planes going up in a smaller and smaller airspace. It's getting hazardous from our own planes in the respect of running into each other," said Johnson, 35.
A smaller battlefield means fewer bombs are needed because the targets are not as spread out, Enfield said, but the higher concentration of people and buildings in the city also means avoiding killing innocent people or hitting civilian targets is more difficult.
"When you are in the city, it takes very precise control, a lot more time and a lot more effort to make sure you are only going to hit your target and nothing else around it," he said.
Pilots are carrying smaller bombs — mostly 500-pound laser-guided weapons — in the hope that they will minimize the collateral damage. In some cases, this has meant warplanes have had to return to targets and bomb them again. In one case, Navy planes bombed a presidential yacht in Basra port three times.
Pilots said they are also required to get visual confirmation of their target before dropping their bombs, a check that is supposed to help distinguish military sites from civilian.
On a mission Friday, Enfield and his wingman were assigned to hit tanks in Baghdad, but didn't drop because they were too close to houses.
On the second mission the same day, near the Baghdad airport, one of the bombs from Enfield's plane went astray and he decided not to drop again because "we didn't want to risk a miss."
The laser guidance system in Enfield's plane had failed, so his wingman, who minutes earlier had successfully guided two bombs onto two tanks, used his system to guide the bomb from Enfield's plane. It missed its target by "a couple hundred meters" and landed among vehicles that had previously been bombed, Enfield said.
He couldn't explain why the bomb missed, and said such incidents were "extremely rare."
Since the war began, flight operations aboard the Kitty Hawk have lasted about 15 hours a day. Two other aircraft carriers in the north Persian Gulf have kept a similar pace, and Air Force and Marine planes have also been operating over Iraq.
Most strike fighter pilots have been flying one three-hour mission a day, sometimes two. Pilots say fatigue is beginning to set in.
A Special Republican Guard headquarters was among dozens of targets hit by 65 bombs dropped by warplanes from the USS Kitty Hawk in missions Friday and early Saturday, Navy spokesman Lt. Brook DeWalt said. He did not provide further details of the site.
The USS Constellation, another of the three U.S. carriers in the Gulf, said its pilots hit more than 50 targets in bombing sorties in the 24 hours to early Saturday.
As the battle concentrates more on Baghdad, "we'll have to be even more aware of what we're dropping on," said pilot Lt. j.g. Greg Kausner, 26. "We want to inflict as little damage as possible on Baghdad and its infrastructure. We only want to take out military targets."