An Air Force effort to revamp its problem-plagued force of MX nuclear missiles is not working, House Armed Services Committee Chairman Les Aspin (D-Wis.) charged yesterday, raising the possibility that new missiles will be deployed without the guidance systems they need to hit Soviet targets.

More than a third of the 28 MX missiles deployed in Wyoming silos lack guidance systems as a result of production delays by a key contractor, the Northrop Corp. The company promised in August to produce six new guidance systems per month, Aspin said, but new production and testing problems have cut this in half.

"Obviously, if these problems persist, there is serious question as to whether the schedule will ever get back on track," Aspin said. "This means we face the prospect of continuing deployment of MXs without guidance systems and the installation of systems that may not perform as required."

President Reagan has called the $19 billion MX intercontinental ballistic missile the centerpiece of his nuclear weapons modernization program; the Air Force has described the missile's accuracy as its most vital military characteristic.

Earlier this year, however, the Air Force suspended MX flight tests because of what Brig. Gen. Charles A. May Jr., Air Force deputy director for advanced programs, said were growing concerns about the missile's accuracy. In August, the Justice Department sued Northrop to recover some of the costs of testing the MX guidance system; the Air Force has continued to withhold some of its payments to the company for MX work.

Aspin also disclosed that a major Air Force review of Northrop's management of the program, scheduled this month, was recently postponed until 1988 because "simply stated, the contractor cannot pass the audit."

Defense Department officials yesterday declined to comment on Aspin's allegations, but in an Oct. 8 letter to Aspin, Air Force Col. Timothy Titus acknowledged that Northrop has "not corrected all of the previously identified management deficiencies."

Titus said "several corrective action milestones have slipped and the Air Force has determined that conducting {a formal audit} at Northrop would not provide any additional benefits to the Air Force at this time."

Northrop's activities will be scrutinized at a hearing today of the House oversight and investigations subcommittee chaired by Rep. John D. Dingell (D-Mich.).