Theodore Harris, president of Airline Industry Resources of McLean, was incorrectly identified Sunday as publisher of Airline Executive and Commuter Air magazines.

When the Civil Aeronautics Board ceases to exist at midnight Monday, it will mean not only the end of a regulatory agency but changes in where consumers buy airline tickets and to whom they should complain if they can't persuade an airline to find their bags.

The CAB's consumer protection regulations -- those that guarantee (among other things) no-smoking sections, reimbursement for lost luggage and compensation for customers bumped from an overbooked flight -- will continue but be administered by a new office in the Transportation Department. For help, call (202) 755-2220.

Perhaps more interestingly, for those who have trouble figuring out how to find the cheapest fare to Peoria, calling a travel agent or an airline will soon be only one of the solutions, industry experts think. It is entirely possible that tickets will be available at supermarkets, car rental agencies or the neighborhood Ticketron outlet, although nobody has announced firm plans yet.

Those changes are possible because, in 1982, the CAB removed the antitrust immunity that designated travel agents as the exclusive sales representatives for the airlines. That ruling takes effect New Year's Day.

The established travel agents are, of course, concerned that they will lose business. They also have expressed fears that new sellers will not offer the same protections that some travel agents offer, such as reimbursement of the ticket price if the airline goes out of business before the flight is called. There are also concerns about the security of the paper that tickets are printed on, and related issues.

The counterargument is that individual airlines are going to be careful about whom they let sell their tickets.

At least one lawsuit challenging the travel agent ruling is pending and there was a related last-minute filing with the CAB by Theodore P. Harris, acting as an individual, although he is the publisher of Airline Executive and Commuter Air magazines. He wants the CAB to reopen the antitrust immunity issue and transfer the case to the Transportation Department while all parties ponder the consequences.

The elimination of the present system, his filing suggests, will force once-impartial travel agents to become wholly owned subsidiaries of specific airlines and thus deprive the consumer of unbiased information.

Some airlines would argue that this has already happened, as most travel agents book flights through computer systems owned by either United Airlines or American Airlines. Although those computers are required by regulation to be "unbiased" in their display of flight information, many smaller airlines feel that is not the case.

Travel agents get a commission, usually 10 percent of the ticket price, which automatically raises the question in a cynical mind of whether some of them are more interested in selling the more expensive ticket or in finding you the cheapest fare.

For years airlines have required that their tickets be sold only through agents approved by the Air Traffic Conference, an industry organization that established standards for travel agents, gave them seals of approval and policed them by pulling their ticket-selling authority if problems arose.

The conference also provided a clearing house where all agent-sold tickets could be processed so receipts could be quickly distributed to the airlines providing the flights.

That structure will also be illegal Jan. 1 because of antitrust considerations. The airline industry has responded by setting up a new group called the Airlines Reporting Corp. (ARC), with many of the same employes and the same offices, in the Air Transport Association building at 1709 New York Ave. NW.

ARC will provide the clearing-house services to the airlines and to those selling tickets if they want them. It will provide the airlines with a listing of agents who have met certain standards, but nothing precludes others from selling tickets for individual airlines.

The Justice Department's Antitrust Division approved ARC last week after months of negotiations. Justice, it said in a letter, has "No present intention to challenge under the antitrust laws the formation of ARC as proposed."

Regardless of where you buy your ticket, the rapid changes in fares and discounts available today makes it a daunting proposition if you are looking for the cheapest ride or the best connection or a combination of both.

William R. Brown, who heads the American Automobile Association's travel agency, the world's largest, said that "first of all you should work with an agent, hopefully an automated agent. Then find an agent who is not lazy but willing to work on your behalf. Our advice is that the consumer should beware."

AAA has gone so far as to subscribe to all five airline computer reservation systems at its center in Falls Church to give its agents the best crack at the cheapest or next available flight.

However, some low-fare airlines -- such as People Express and Southwest -- have chosen not to permit sales of their tickets through the computer systems, which means the travel agents have to book by telephone, something many do not like to do.

The other area of consumer concern is more easily explained. There are no changes in the CAB's baggage, no-smoking, overbooking and charter protection regulations, which were transferred intact by Congress to the Transportation Department.

Those regulations, summarized briefly, are as follows:

* No smoking. Cigars and pipes are prohibited on all flights. Cigarettes are prohibited on planes with fewer than 30 seats. On planes with 30 or more seats, passengers must be given a seat in a no-smoking section if they have checked in on time.

* Lost baggage. If an airline loses your luggage it is liable, to a maximum of $1,250, but you must be able to prove the loss is of that magnitude.

* Overbooking. If a flight is oversold (and many are), an airline can offer cash, free future flights or other inducments to persuade seated passengers to surrender their seats. If that fails to create enough room for irate unseated folks holding confirmed reservations, the line may bump a passenger involuntarily but must deliver him to the same destination within an hour of the original arrival time. If that is not possible, the line has to provide transportation to the destination plus the price of the ticket, to a maximum of $200. The same is true on international flights departing the United States, but not those destined for the United States, and the maximum is $400, not $200.

* Charter protection. There are many complicated rules protecting passengers who book charter flights. They are designed primarily to assure that the charter operator has the money to guarantee the existence of the plane when the flight is scheduled and to assure the passenger reimbursement if something goes wrong. Nonetheless, every summer there is at least one horror story about a planeload of charter passengers stranded overseas with little money and tickets that no one will accept.