A U.S. AIR BASE, Eastern Saudi Arabia (AP) _ Pilots of A-10 tank killers granted a mother's wish and carried the photograph of her slain son with them in the last days of the Gulf War.

''I am writing to you to let you know of a fine young man that flies with you in spirit,'' said a letter received Tuesday by the 76th Tactical Fighter Squadron from Sylvia Gay of Centerville, Ga.

''His name is John Matthew Gay, and he was my son. He was murdered this summer eight days after his 15th birthday. His death was a great and senseless tragedy.''

In a telephone interview, Mrs. Gay said she was thrilled to hear the pilots were carrying the photo.

''I'm so excited,'' she said. ''I just wasn't aware all this would come from this letter. It was just something I needed to do for my own healing process.''

Mrs. Gay said her son was shot to death last summer during an argument with his 13-year-old sister, who is being held on a juvenile murder charge at a state youth detention center in Macon, Ga.

In her letter to the squadron, she described John as an honor student who was fascinated by A-10s, which he had studied and knew in detail. Mrs. Gay said he had dreamed of graduating from the Air Force Academy and flying A-10s.

''It was his goal, his life,'' she said. ''There was no doubt that he would attain this dream. I know that he is there in spirit with you and each of the other pilots.

''I am enclosing a small picture of of John taken shortly before his death. I hope you can take it up with you on one of your missions. It would mean a great deal to me.''

The photo is a school picture showing her son wearing shorts and a T-shirt, she said in the telephone interview, and added: ''Unless there are A-10s in heaven, which I hope there are, this would be his only chance to fly.''

Lt. Col. Gene Renuart, 41, of Miami, the squadron commander, told reporters Tuesday a pilot took the photo on a mission immediately and ''John's picture's going to fly with us every day.''

''He's flying now, and he'll fly with me tomorrow and with us every day until the war ends,'' Renuart said. ''And we're putting his name on one of our missiles each day when we fly.

''We just want his family to know that we received her letter and that we're going to do that for him.''

John's father, Dan Gay, told a reporter: ''That's great 3/8 That's marvelous, that's marvelous.''