The Senate is about to vote on a bill to transfer ownership of two of the major airports serving this region -- National and Dulles -- from the federal government. I have strongly and persistently opposed this legislation, which The Post supports (most recently in an editorial of April 9). I oppose it because of the adverse impact I believe it would have on both residents of the area and the region's third major airport: Baltimore-Washington International.

All agree that major improvements are needed at the two federally owned airports. But whether the airports should be transferred from federal ownership, and if so how and on what terms, are more controversial questions. The Airport Transfer bill before the Senate fails to recognize that all three airports serve the national capital area and that a fair, competitive airport policy will result in better air services.

In 1984 Transportation Secretary Elizabeth Dole directed a commission, chaired by former Virginia governor Linwood Holton, to devise a plan for divesting the federal government of National and Dulles. The commission's final report ignored the sensible Maryland proposal to transfer National to an interstate authority and sell Dulles to Virginia.

Under that proposal, National would be operated by an interstate authority including federal representatives along with three members each from the District of Columbia, Virginia and Maryland. Virginia could develop Dulles in the same way Maryland has developed BWI, thus enabling these two directly competitive airports to compete on an equal footing.

That proposal would avoid the deficiencies in the Senate bill. These deficiencies include:

*Unequal representation on authority board governing the airports.

*Cross-subsidization, permitting the authority to use profits from one airport to subsidize the other -- highly profitable National could underwrite Dulles -- in unfair competition with BWI.

*Incredibly low prices for both facilities, in which hundreds of millions of dollars have been invested.

*Potential use of thousands of acres at Dulles for nonaviation purposes.

*Power of the authority eventually to use the transferred properties for purposes unrelated to aviation.

*Inadequate protections for current airport employees.

*The prospect of increased nighttime use and noise at National.

By focusing on National and Dulles as a single unit, the bill sets up an unfair competitive situation for BWI and places in jeopardy BWI's ability to provide high-level service to the entire region.

At the heart of this problem is cross-subsidization between National and Dulles, allowing revenues at one to underwrite costs at the other. While the bill limits somewhat direct cross-subsidization, it contains a loophole as wide as a hangar door, permitting any revenues at one airport to be used for debt service and depreciation at the other, and some revenues, such as concessions and leases, to be used for any costs at the other. Clearly, the loophole swallows the limitation.

Whatever the arguments over selling the airports, $47 million -- to be financed with tax-exempt bonds over 35 years -- is hardly a serious price. Estimates of the two airports' value range in the hundreds of millions of dollars.

From both the fiscal and competitive perspectives, therefore, the proposed transfer is indefensible. It is further unacceptable because it would open the way to repeal of nighttime noise limits, which local communities fought long and hard to obtain. Area residents, especially Marylanders, who are particularly affected by National's flight patterns, face the prospect of round-the-clock airport operations.

The composition of the 11-member authority -- five from Virginia, three from D.C., two from Maryland and three national -- rides roughshod over the regional, and indeed national, interest in air service for the capital. BWI and Dulles are, after all, equidistant from downtown Washington, and both have important roles to play in the region's air transportation network.

BWI is proof that a state authority can turn a struggling airport into a success. Fourteen years ago Maryland purchased Baltimore's Friendship Airport and, with hard work and an investment in current dollars of over $250 million, created an efficient and convenient airport. Virginia can certainly do as much with Dulles, and Maryland would welcome the competition. Because National is a vital concern to residents of the District, Maryland and Virginia alike, it should be placed under a genuinely tripartite local authority. With such a balanced approach, we could all get on with the job of providing quality air service for the national capital area.