White House Chief of Staff John H. Sununu has used military jets for more than 60 trips over the past two years, in many instances for what appears to be personal or partisan political travel, including flights to Colorado ski resorts, to his home state of New Hampshire and to Republican fund-raising events.

A presidential spokesman said White House policy requires Sununu to use military planes in order to stay in "immediate voice contact with the White House at all times." Neither he nor Sununu's office would say whether any personal or political trips had been reimbursed at full commercial rates, as the policy also requires.

That reimbursement rate, in any case, would have covered only a fraction of the flights' actual cost to the government -- more than a half-million dollars in Sununu's case.

The travel records show that Sununu, three-time governor of New Hampshire, has made 27 trips to his home state, or to nearby Boston, on military planes.

In December 1989, Pentagon flight records show that Sununu and two other passengers flew from Andrews Air Force Base here to Salt Lake City and then on to Vail, Colo., on an Air Force jet. The plane returned here without any passengers, then flew back to Vail empty again three days later to pick up Sununu's party. Flying time: 16 hours.

The trip cost the government more than $30,000, based on standard Air Force charges. A commercial flight to Vail for a single passenger would have cost about 90 percent less.

Sununu made a similar trip to Aspen, Colo., last December. This time the plane flew from Aspen to nearby Grand Junction, Colo., where the crew, usually five Air Force personnel, stayed over two nights before flying back to Aspen to take the Sununu party home.

By then the hourly rate the Air Force uses to compute costs had increased to $3,945 and the eight hours of flying cost more than $30,000. The current full round-trip commercial coach fare between Washington and Aspen is $1,076.

A spokesman for Sununu, Edward Rogers, said the chief of staff "has no comment and will not discuss this with you." Asked repeatedly if Sununu had reimbursed the government for any personal trips, Rogers said, "no comment."

Independent research by The Washington Post was able to determine that at least $8,900 had been paid to the government for Sununu travels.

For all but one of the flights, Sununu has flown in a C-20, the 12-passenger military version of a Gulfstream III long-range corporate jet.

The Air Force computes the hourly flight cost of the aircraft for White House trips without counting the salaries of the normal five-member crew. The Pentagon charges other government agencies more for the same plane because the other agencies must pay the salaries. That total charge is now $5,329 an hour, according to the Air Force. By comparison, commercial charter of a Gulfstream III costs about $3,750 an hour.

The Sununu travel records, made available by the Pentagon at The Post's request, cover flights on which he was the principal passenger, not those on which he accompanied the president on Air Force One.

Because the White House declined to provide any documentation or explanation for Sununu's travel, which exceeds that of other recent chiefs of staff, it is not known which trips were official White House business.

One official flight was the only foreign trip he has made as White House chief of staff. He and a delegation took a larger military plane to the Soviet Union last August, to tell officials there how a chief of staff's office works.

Until 1987, the White House practice was that senior officials, such as the chief of staff, generally traveled by commercial aircraft when on personal trips, according to officials of the administrations of former presidents Jimmy Carter and Ronald Reagan.

Presidential press secretary Marlin Fitzwater said in a formal statement that the chief of staff and national security adviser now travel under a directive that "for a number of communications and security reasons requires them to have immediate voice contact with the White House at all times."

The policy, unannounced publicly at the time, began in August 1987, a few months into the tenure of Reagan's third chief of staff, Howard H. Baker Jr. He had been brought in to help pull the Reagan presidency out of the troubles of the Iran-contra controversy.

However, the man who succeeded Baker and served as Reagan's last chief of staff, Kenneth Duberstein, flew commercial on the few private trips he took, according to officials from the Reagan White House.

In his statement, Fitzwater said: "When travel is for personal or political reasons, the government is always reimbursed at full commercial passenger rates."

An administration official familiar with the reimbursement requirement said that the government is supposed to be reimbursed at "immediate coach fare" plus one dollar. He said that means the official, or sponsoring political group, pays the cost of a one-way coach ticket to the destination and another identical fare back "as if he bought each ticket at the gate that week."

The Post was able to find two examples of reimbursement. The Republican Governors Association, where Sununu's wife, Nancy, works as a fund-raiser, reimbursed the Treasury $5,168 for travel of Sununu and three Cabinet members to a fund-raising appearance in St. Louis last April, an association official said Friday.

And a Sununu campaign committee in New Hampshire, where he was governor, paid the Treasury $3,768 last July for unidentified travel and other expenses.

About the same time, the chief of staff missed the July installment of $2,060 in property taxes on his Fairfax County home. By December he had made most of the payment, plus some penalty and interest, according to tax records.

But he then was late on $9,430 in property taxes on his New Hampshire home and the lot next door that was due that month. He paid the New Hampshire tax, plus an additional $413 in penalty and interest, according to the county tax clerk, in February. This was after a reporter inquired about the issue.

Sununu, who has eight children, took out a $420,000 loan on his New Hampshire home in 1989 to pay for the suburban Virginia house.

On his 1989 financial disclosure statement, Sununu reported that his wife earned $34,272 from the fund-raising job with the Republican Governors Association, while he received $84,387 from his White House job and $9,151 from his governor's salary in New Hampshire. In March 1990, Nancy Sununu received a $19,500 "consulting contract" from a separate Republican National Committee fund that the party did not have to disclose publicly.

Checks of local newspapers around the country turned up explanations for some of Sununu's trips. For example, he accepted an engineering award in Chicago and an honorary degree at Marquette University in Milwaukee.

Sununu and his wife were in Colorado in December of both 1989 and 1990 at conferences sponsored by Ski magazine, according to editor Dick Needham. The trip last December was to Aspen, during the Persian Gulf crisis. "He was doing it on his own nickel," Needham said, noting that the magazine didn't pay any of the Sununus' expenses. "He comes for the pure enjoyment of skiing with us."

Sununu's first recorded use of a military jet was April 15, 1989. The plane flew without any passengers to Manchester, N.H., about 15 miles from Sununu's home in Salem. It returned early the next day with Sununu aboard. The flying time was about 2 1/2 hours. At the $1,892 hourly rate used at the time, the trip cost the government about $4,730. One-way coach fare for one from Manchester to Washington now is $295.

He made 22 flights in 1989, half of them to New Hampshire or Boston. Other destinations, besides Vail, included Los Angeles, San Francisco, and Gainesville and Tallahassee, Fla.

Sununu was in San Francisco with Commerce Secretary Robert A. Mosbacher in June 1989 to attend the American Academy of Achievement "Salute to Excellence" weekend, according to academy director Wayne Reynolds. The group gathers celebrities from sports, show business, business and politics with top high school students.

The 10-hour flight time would have cost about $19,000. The current round-trip coach fare between Washington and San Francisco is $1,262.

In October 1989, Sununu was in Gainesville to speak to the University of Florida homecoming banquet, according to the Orlando Sentinel. Both U.S. senators from the state and two House members also attended.

In December, Sununu was in Tallahassee to speak at a fund-raising event for Rep. Bill Grant, who had recently switched to the Republican Party.

Last year, Sununu made 41 trips on military planes, including ones to the Indianapolis 500 auto race, a charity ski event in New Hampshire he helps sponsor to honor the late Challenger shuttle crew member Christa McAuliffe, and political fund-raisers for incumbent governors in Kansas and Nebraska.

Sununu was scheduled to attend the Indy 500 as Vice President Quayle's guest last Memorial Day weekend. It appears he may have accompanied Quayle to Indianapolis on Air Force Two because the C-20 assigned to Sununu that May 25 flew to Indiana without any passengers.

The next day, Saturday, the plane flew Sununu and another passenger to Akron, Ohio, where he gave a commencement address at the University of Akron and attended a luncheon with Republican fund-raisers. The same day Sununu and another passenger flew to Boston, and Sununu flew back to Indianapolis.

Sunday, the day of the auto race, Sununu's plane flew back to Andrews without passengers. The total flying time was about 7 1/2 hours, which cost the government more than $14,000.

The use of military planes has long been a sensitive issue. The Air Force keeps a fleet of planes, including Air Force One and Two, to support the president. They are assigned to the 89th Military Airlift Wing at Andrews Air Force Base. Cabinet members, members of Congress and military brass also use the planes periodically.

Former White House officials said they recall disputes in past years over who could get a plane when and who should pay for it. The issue was whether a trip would be designated a "presidential mission," which meant the Pentagon would pay for it. Otherwise agencies would have to pay for the travel out of their own budgets, and at the higher hourly rate. Then-Secretary of State George P. Shultz testified during the Iran-contra hearings that he had threatened to resign over one such dispute.

Tom Griscom, who was White House communications director in 1987, said it was at Shultz's urging that President Reagan signed an order saying the chief of staff, then Baker, and the national security adviser, then Frank C. Carlucci, should take military flights so they could be reachable at all times.

Baker, who was flying home to Tennessee to visit his ill wife, carried a portable scrambler in a briefcase so he could make secure calls while on the ground, Griscom said.

Reagan's first chief of staff, James A. Baker III, flew commercially on the handful of personal trips he took, aides said. Donald T. Regan could not be reached, but former officials said he traveled commercially on most personal trips.

Staff researcher Lucy Shackelford contributed to this report.