The private jet is a time-honored freebie that our federal officials are loath to surrender to budget cuts. Why mingle with the masses in the airport when there is a government plane to take up for a spin? A congressional investigation indicates that bureaucrats are ignoring rules requiring them to use government planes only if they are less expensive than a commercial flight.

Weighing the cost of a flight appears to be the exception more than the rule for bureaucrats. A preliminary report prepared for the Government Operations subcommittee on government information, chaired by Rep. Glenn English (D-Okla.), shows that most agencies use the government planes whenever there is an excuse to fly.

Before they take off, officials are supposed to meet two criteria established by the Office of Management and Budget: They have to prove that the same flight is not offered at a cheaper price by commercial aircraft, and they must show how the trip can be justified economically.

Investigators studied eight agencies and 28 aircraft and found that the first requirement was rarely met and the second was ignored.

The report, obtained by our associate Jim Lynch, also noted that Department of Energy officals continue to fly thousands of hours each year, despite a recommendation from the department's inspector general in 1986 to stop using the DOE planes as air taxis for staff workers. The DOE policy is that private planes should be limited to the vital "missions" of the DOE instead of "administrative" uses, but no one in DOE has ever defined what the difference is. The interpretation has been left up to the field offices or ignored. DOE spends $34 million a year on airplanes.

The DOE's Bonneville Power Administration stores two Beechcraft King Air 200s in Portland, Ore. The two planes were flown 831 hours between July 1986 and July 1987 at a cost of more than $800,000. More than 90 percent of the trips were made to ferry officials to meetings, and about 75 percent of them were to areas served by one or more commercial airlines.

The Western Area Power Administration classified most of its passenger flights as "missions," the investigators found. The agency made cost comparisons between flying commercially and using the government planes, but the comparisons "were frequently disregarded when they showed that commercially available flights were less costly," a December 1987 inspector general's report said.

The Federal Aviation Administration has four jets that were flown almost 3,000 hours without officials justifying the trips under the OMB criteria. Those flights cost more than $2 million.

The National Aeronautics and Space Administration uses its Beechcraft King Air 200 to fly officials to what is considered a remote location: Wallops Island, Va. But there is a commercial airport within a one-hour drive of Wallops Island. NASA has a jet in Burbank, Calif., that also flies officials to remote sites. It cost about $600,000 to fly the jet 717 hours during the period the examined. NASA did not meet either of the criteria for flight approval.