Sen. Barry Goldwater, the man who wanted to get government off your back before Ronald Reagan got political mileage out of the same theme, is also a pragmatist. An ex-Air Force Reserve general and still an aviation enthusiast, Goldwater recently told a trade paper, Airport Press, how disappointed he is in the actual results of airline deregulation.

"I thought the deregulated airline industry would revert to the virtues of private enterprise and arrive at sensible ticket prices," Goldwater said. "Instead you can fly to the same place for 10 or 12 different prices. The airlines are their own worst enemies." Goldwater, nonetheless, thinks reregulation "won't help a damn bit."

Apart from the financial problems created by deregulation, other problems arise when the government, or some other cop, isn't policing the beat to look after the public interest. For example, Goldwater is outraged by "woefully inadequate medical kits" carried on U.S. airplanes. According to the old flyer, they fail to stock drugs and equipment useful in handling such emergencies as heart attacks, choking, severe allergic reactions and bleeding.

He's introduced a bill that would require the Federal Aviation Administration to issue a regulation forcing the airlines to stock such drugs and equipment--which is no more than many foreign airlines, including Canada's, now require.

Another necessary reform proposed by the senator: believe it or not, pilots no longer have to take stress tests as part of their normal physical exams. Goldwater, as much as anyone, knows how important a stress test can be. His own urgent need for coronary bypass surgery didn't appear until he was given a treadmill test, after an electrocardiogram at rest showed normal heart action.

Apart from ensuring adequacy of health and safety precautions, something has to change to get rid of the fare-making chaos. However well-intended, fare deregulation has created a veritable jungle for the industry and for travelers.

Worst of all, fare "wars" have produced unfair prices. Frequently, it costs a great deal more to travel a shorter distance than a longer one--an anomaly for which there is no rational explanation or economic justification. And often, the fare "bargains" apply to a very limited number of seats.

Now comes American Airlines with a proposal--on its own--to establish a rate structure based on mileage.

Starting April 2, American will base regular coach fares on the length of the trip --lower per-mile rates on longer trips, higher per-mile rates for shorter trips. Instead of the below-cost $99 cross-country rate that has been available, American's basic round-trip rate will be $399. American says that coach fares will drop slightly on 720 routes and be increased on 543 routes.

Thus, for the first time, a major carrier is conceding what critics, including the Air Line Pilots Association, have been saying all along: deregulation has distorted air fares. In the end, so many airlines will be driven out of business that there will be a bare handful of giant carriers left.

But whether or not American's proposal works depends on whether the other airlines will go along. If they all do, it would restore the kind of fare basis that prevailed (at lower mileage rates) before deregulation. Some say they will follow American's lead, although there is a possibility this will be attacked as an antitrust violation.

A knowledgeable source in a government agency flatly predicts failure. "It won't work," he says. "No single carrier or group of carriers can rationalize the structure. All it takes is for one carrier to bust the agreement. I think that the fare war, and inequitable pricing, will continue."

American Airlines' marketing vice president, Thomas G. Plaskett, in explaining his company's solo decision, said that under deregulation, "the explosion in the number and complexity of fares has produced tremendous confusion. . . . At the same time, fares have reached a point where the price paid by the customer bears no logical relationship to the distance traveled."

The sensible course is to go back at least part of the way to regulated fares, as much as that may be anathema to free- market theorists. There is no real free market in transportation, whether it's transporting people or natural gas, and it's foolish to pretend otherwise.