One result of the Deficit Reduction Tax Act, enacted in June, is that it prohibits the refunding of already outstanding airport revenue issues after Jan. 1, 1985. Because of this cap, in recent months issues totaling $750 million have been refunded along with the sale of $730 million in new airport issues.

This prohibition also means that there will be fewer large, highly liquid airport issues in the future. As such, the recent issues could develop a scarcity value, and it just might make good sense to put these recent issues away in a safe-deposit box, bring them out in several months, when a scarcity value has developed, and then use them as good swap candidates against cheaper issues.

Jerry Webman, a municipal analyst at Merrill Lynch, believes that buying an airport revenue bond is a tricky investment maneuver that entails several considerations. The airport itself requires a large capital expenditure to be functional. And this means a large income stream from the airlines that use the airport is necessary to keep it running and, most important to the investor, to handle the debt service on the outstanding bonds. This is one of the reasons for the recent refundings -- to obtain a lower interest cost on the outstanding debt. Other refundings were done to get out from under onerous indenture restrictions on some of the outstanding issues. These indenture restrictions severely limited the sale of new issues to further large capital expansion programs.

The other key to airport revenue bonds is the airlines that use the airports, and the strategies they use in their operations. Deregulation has caused the airlines to rethink their game plans and make certain adjustments to stay alive. These new plans have proven beneficial to some airports, but quite harmful to others. Consequently, the bondholder could be left holding the proverbial bag if a major airline shifted its operations to another airport.

In an effort to be more profitable, airlines have gone to a "hub and spoke" strategy. This means that an airline might use one airport as the hub in its operations, using smaller planes to feed passengers into the hub, where they may be transferred to larger planes headed for one destination. For example, Charlotte, N.C., is Piedmont's hub in the South. Passengers flying north to Washington, D.C., would be flown to Charlotte from Tampa, Fla., Myrtle Beach, S.C., and Dallas and then be flown on a single flight to Washington. Consequently, Charlotte has become a more important airport, as has Newark because of People Express Airlines.

One airport harmed was the one in Kansas City, Mo. This beautiful airport was banking on Trans World Airlines using the Kansas City airport as its hub. But TWA elected to set up its operation at Lambert Field in St. Louis, which now is reaping the benefits of having a major carrier such as TWA using it as one of its hubs. Conversely, the Kansas City airport obviously has missed the gold ring.

There are other factors as well: the competition among airlines; the huge fixed costs of the major carriers; the area being serviced; and the price wars that occasionally pop up. At any rate, be careful in your selection, and know all the facts. Here are some analysts' choices for better airport bonds: Chicago O'Hare, Dallas-Fort Worth, Denver-Stapleton International, and City of Los Angeles International.

Airports that should be carefully watched are McCarren International Airport-Las Vegas; and the airports in Broward County, Hillsborough County and Orlando, all in Florida. The Florida airports are involved in frequent price wars against the major carriers. Be careful, and don't fall for any high fliers!