SARAJEVO, Bosnia-Herzegovina (AP) _ Braving missile and small-arms fire, U.S. Marines flew a helicopter into hostile Serb territory and rescued an American F-16 fighter pilot shot down six days ago by rebel Serbs.

Capt. Scott F. O'Grady of Spokane, Wash., was found alive and well near where his plane went down southeast of Bihac in a Bosnian Serb stronghold.

Adm. Leighton Smith, commander of NATO forces in southern Europe, said a pilot from O'Grady's squadron was flying an F-16 over the area around midnight when he heard O'Grady's voice on the radio.

Smith said the pilot conserved the batteries in his survival radio by using it only sparingly and when he thought he could make contact. A NATO source said O'Grady kept on the move until he got to a location when he could be rescued.

A Serb missile had blown apart O'Grady's fighter jet on Friday as he flew a NATO mission over northern Bosnia. His fate had been unknown. There were some initial reports the Serb rebels had captured him.

The military mounted a big rescue operation at dawn and two CH-53 helicopters landed 50 yards from where the 29-year-old O'Grady was hiding in the woods. He dashed out of the trees to the nearest helicopters and was hauled aboard by Brig. Gen. Marty Berndt.

``It won't be very soon that I'll forget the look on his face as he approached the helicopter this morning,'' said Berndt, speaking via telephone from the Kearsarge, an American carrier in the Adriatic.

He told NBC-TV that O'Grady ``was very talkative and in a very good spirit.''

He said soon after O'Grady was pulled onto the helicopter he took some water, then ``dug right into a meal ready to eat, or MRE, so he must have really been hungry.'' He said O'Grady had not eaten for the six days he was down.

The downing of O'Grady's plane added to tensions following the abductions of hundreds of U.N. peacekeepers by Bosnian Serbs retaliating for May 25-26 NATO air attacks on their ammunition depots outside Pale, the rebel headquarters nine miles from Sarajevo.

Today's rescue mission included a Marine team and CH-53 and Cobra helicopters from the USS Kearsarge. They were escorted by F-18s and electronic warfare planes.

``We had the whole shooting match up there,'' including Cobra helicopters, Harriers, AWACS radar planes and other support aircraft, Smith said at a news conference at U.S. Naval Headquarters in London.

Berndt, who pulled O'Grady on board, ``is a pretty strapping young guy,'' Smith said. ``He saw the pilot come running out of the woods, so he grabbed him and snatched him aboard and they got out of there.''

Berndt said a missile was fired at the helicopter after O'Grady was picked up. Smith said it missed. He said small arms fire at the helicopters also missed.

O'Grady was flown to the Kearsarge, an amphibious assault ship that has a 600-bed hospital, and the medical report is ``very good,'' Smith said.

Asked how O'Grady survived a six-day ordeal after being shot down, the admiral said, ``Whatever it was, it sure was right.''

``He maintained his cool,'' said Smith. ``He's very smart, he's very determined and very gutsy to have evaded for as long as he did using the equipment that he had.''

Stacey O'Grady, the rescued pilot's sister, spoke to her brother early this morning. ``He can't quite understand what all the big fuss is about,'' she said.

She told CBS-TV that O'Grady is dehydrated and has a slight burn on his neck, but is otherwise in good condition.

``He said that he was only able to eat about three spoonfuls of food,'' she said from Washington, D.C.

At NATO headquarters in Brussels, Gen. John Shalikashvili, chairman of the U.S. Joint Chiefs of Staff, said of the pilot: ``I am told that he is well, that he has a six-day beard and that he has a small burn on the back of his neck as a result of exiting the aircraft.''

O'Grady is assigned to the 555th Fighter Squadron at Aviano Air Base in northeastern Italy. He'll be taken there from the Kearsarge, which is carrying members of the 24th Marine Expeditionary Unit who were sent to the Adriatic from the Mediterranean on May 29.

President Clinton called O'Grady's parents in Seattle to share their happiness.

``All Americans rejoice with me at the successful rescue of Capt. Scott O'Grady tonight and join his parents in their relief after days of uncertainty and anguish,'' Clinton said in a statement.

``Capt. O'Grady's bravery and skill are an inspiration,'' Clinton said. ``So are the bravery and skill of those who took part in the operation to rescue him. They are all American heroes.''

Defense ministers of the 12 NATO countries meanwhile were meeting today in Brussels, Belgium, to consider plans either to evacuate 22,500 embattled peacekeepers from Bosnia or send a heavily armed 10,000-member force to protect them.