Personal trips taken by Secretary of State George Shultz on his military aircraft over a 30-month period cost the government nearly $1.9 million, with Shultz paying only the price of economy-class airfare, a congressional report says.

The General Accounting Office report says Shultz took 23 personal trips during the 30 months ended last July, most of them visits to family homes at Stanford University in Palo Alto, Calif., and Cum-mington, Mass. Most of the time Shultz was accompanied only by his wife, Helena.The total bill for those trips came to $1,892,214, GAO told the House Government Operations Committee in a report released Wednesday. Most of the money was spent for Shultz' military plane, its sophisticated communications equipment and the secretary's security personnel, the review said.

Shultz reimbursed the government for less than 1 percent of the cost, $1, State Department officials told the GAO.

The total amount Shultz reimbursed the government was $18,783, the GAO said.

Shultz' annual Cabinet salary is $99,030. His net worth is unavailable, but his financial disclosure form filed earlier this year shows that a blind trust created from his holdings had income last year in excess of $100,000.

State Department spokesman Charles Redman said Shultz used the military plane because "the secretary of state is the secretary of state 24 hours a day, 365 days a year," no matter where he is.

Redman said Shultz has followed the practice used by other secretaries of state for the past 15 or 20 years. Many other Cabinet members also use military aircraft for reasons of improved security and communications, he said.

Redman added, "The fact of the matter is that the security threat doesn't disappear just because the secretary happens to be on vacation, nor does the need for communications."

The bulk of the $1.89 million cost for the 23 trips went for military aircraft - $797,219, the GAO said. Hotel accommodations for security personnel and other aides cost $336,414; overtime for those personnel cost $256,205; per diem food costs were $183,030; and $141,464 was spent to install telephone lines.