Air Force leaders said yesterday they expect to run short of volunteers this month for the first time since the draft ended in 1973.

Brig. Gen. William P. Acker, commander of Air Force recruiting, said preliminary figures indicate his service will fall 800 short in trying to recruit 5,468 persons for December.

Other military services have run short of volunteers since draft calls ended, but for the Air Force it would be a first.

Acker attributed the shortage to an improved civilian job market for teen-agers, a declining population of 18-year-olds, and traditional reluctance to enlist during Christmas month.

Although the Air Force hopes to make up its expected 15 percent December shortfall, Acker said in a telephone interview yesterday that he could not be certain. "It looks tough for spring, too," he said.

This latest evidence of the military's increasing difficulty in filling ranks completely with volunteers is expected to generate fresh demands in Congress to reconsider the 1973 decision to end the draft.

Another effect of the growing recruiting problems is likely to be a reluctance in Congress next year to overhaul military retirement, which is now costing about $10 billion a year and, according to a presidential commission, should be revised.

President Carter went on record in Memphis last week as saying he favored a much different draft system if it were reinstituted. Without advocating a return to the draft, the president said:

"I never thought it was fair. I thought it was extremely unfair to give exemptions for all young Americans who had the financial resources to stay in college.

"I think in the future, if we should have a draft system, it ought to be absolutely universal. And if we have to take a limited number of young people into the armed forces, they ought to be on drawing lots, and when somebody is in college or working on a farm or relatively illiterate, they ought to be handled in the same, exact way."

He said that the all-volunteer force is being constantly assessed and that "no conclusions have yet been reached" as to whether it should be replaced with some kind of universal draft system. He noted that Chairman John Stennis (D-Miss.) of the Senate Armed Services Committee and Sen. Sam Nunn (D-Ga.) "have been very interested in assessing whether or not it would be advisable" to return to the draft.

Air Force Gen. David D. Jones, chairman of the Joint Chiefs of Staff, long has swarned against tinkering with present military benefits for fear of dispiriting people already in the services and prompting them to leave.

Air Force Gen. John W. Roberts, commander of the Air Training Command, sounded the same warning in a recent speech. He declared: "The 'great way of lift' which was so willingly endorsed by the public in exchange for dropping the draft has seen some significant erosion . . . The 'great way of life' we offer isn't as great as when the all-volunteer force was conceived and adopted."