In an editorial {"A Senate Threat to Air Safety," Oct. 11} that mischaracterizes the purpose and effect of pending legislation, The Post argues that the interests of Washington must be served before the interests of the country.

S. 2851, the Airline Competition Equity Act of 1990, is not some piece of special interest legislation as The Post seems to suggest. Rather it is the product of an extensive investigation into the deregulated airline industry conducted by the Senate Committee on Commerce, Science and Transportation during the course of several years and two Congresses. This investigation generated six committee hearings and six separate reports by the Department of Transportation, the General Accounting Office and the airline industry.

Slots are takeoff and landing rights at four airports: New York LaGuardia, New York Kennedy, Chicago O'Hare and Washington National. An airline must hold a slot to take off or land at these airports, but no others. Slots were put into place in 1969 to smooth traffic at these busy airports. Since then, improvements in the air traffic control system allow for the busiest airports in the country -- Los Angeles International, Dallas/Fort Worth, Atlanta Hartsfield -- to operate safely without slots.

While the Commerce Committee's review cited numerous problems in the airline industry, everyone agreed on one diagnosis -- the slot system discourages competition. In testimony before the Commerce Committee on S. 2851, DOT's representative stated that many airlines cannot enter these popular markets to offer service because the airlines that hold slots are able to control them to keep out competitors. According to the GAO, this "can impede competition throughout the northeastern and midwestern United States... . It is difficult for any carrier to become an effective competitor in these heavily populated parts of the country without access to these four airports."

Slots raise the fares of travelers flying in and out of these airports, including Washington Metropolitan area residents. In its 1990 study of airline competition, DOT found fares 15 percent higher at National and LaGuardia because of slots. The GAO found that fares are 7 percent higher at the four airports.

In addition, safety was never a consideration in the slot rule's original promulgation, nor is it a consideration now. The DOT assured the committee in its testimony that safety would not be compromised if slots were removed.

This legislation benefits the whole country. It phases out monopoly rights that result in higher fares and inhibit competition nationwide. The measure first eliminates the practice that allows the airlines to control the distribution of slots. Second, it will permit one or two extra operations an hour at the four airports by airlines that have not been able to get slots. Third, monopoly rights to airport access will be eliminated altogether, allowing the FAA to control traffic at these airports as it does at other busy airports. Contrary to The Post's implication, this is not a bill to benefit a single state or a single airline.

JOHN C. DANFORTH U.S. Senator (R-Mo.) ROBERT W. KASTEN JR. U.S. Senator (R-Wis.) Washington