IN NORTHERN SAUDI ARABIA (AP) _ U.S. Army Apache helicopters attacked tanks and gun positions inside Iraq in a night raid one returning pilot called ''a turkey shoot.''

The Apaches, in an early Monday assault more than 50 miles inside Iraq, knocked out two tanks, one armored vehicle and several trucks, according to preliminary reports.

Some pilots reported receiving anti-aircraft and small arms fire, but none of the Apaches was damaged, officers said.

''We dealt him some serious punishment,'' said Maj. Lee Stuart, executive officer of an attack battalion for a paratrooper division. ''We caught him totally by surprise.

''The Air Force has been after them 24 hours a day. Now all of a sudden somebody's coming out of the ground after him. They probably got the fear of God put in them,'' said Stuart, 43, of Jonesboro, Ga. ''The Apaches rule the night.''

The high-tech Apache, the Army's highly touted tank killer, attacked without running lights, using infrared sensors and invisible laser beams. Pilots said they fired laser-guided Hellfire missiles, 2.75-inch rockets and 30-millimeter cannon at Iraqi tanks, air defense artillery and artillery positions.

''It was not a good night for the Iraqis,'' said Capt. Jess Farrington, 32, of Milton, Fla., a company commander. ''We caught them with their shorts down. They were in their sleeping bags. It was a turkey shoot.''

Capt. Robert Tuggle, also a company commander, said he saw a tank hit and then witnessed secondary explosions from fuel tanks or munitions going off.

''We got some real good hits. That thing lit up the battlefield,'' said Tuggle, 31, of Columbus, Ga.

''It's like playing a video game,'' he added.

Tuggle said the Iraqis were confused and disorganized. ''They didn't know which way to run.''

It was the first combat mission for many of these pilots, and all rated it a nerve-wracking success.

''We've been sitting here waiting almost seven months to do something,'' said Chief Warrant Officer 2 Mike Brillant, 28, a pilot from Fort Lauderdale, Fla.

''We did what we wanted to do the way we planned it,'' said Capt. Stewart Hamilton, 34, of Haven, Kan., operations officer for the attack battalion. ''We were hand-delivering ordnance. He could hear us but couldn't see us. I think it scared the daylights out of him.''

The thundering Apaches are indeed frightening, resembling giant insects from another planet. And some expressed a tinge of regret because the high- tech weaponry gave the Iraqis no mercy.

''It's almost kind of cheating,'' said Staff Sgt. Michael Osborne, 37, of Monterey Park, Calif.

Before the Apaches left, crew chiefs painted personal messages on their Hellfire missles.

Pfc. Thomas Nowacki, 21, of Detroit used colored chalk his mother had sent him to write ''Camel Smoker'' on one. Others messages included:

''When you care enough to send the very best.''

''Eat this.''

''Baghdad Express.''

''This Bud is for you.''

''It's just something personal,'' Nowacki said. ''We're done messing around. They won't even hear it. It'll just waste them.''