New D-Day Invasion Being Aided by Low-Price Tickets : Fares: Many airlines are offering discounts for veterans and families going to France.

If you’re old enough to remember 1944 and you’re thinking about traveling to France during this D-day anniversary year--as thousands of veterans and others are--you should probably also be thinking about discounted air fares.

Even though the principal dates of the Normandy invasion’s 50th anniversary fall early in June, normally a costly travel month, Air France and British Airways are running 30%-off D-day discount programs through that month and all of 1994. In both cases, travelers have a chance at LAX-Paris round-trip fares of about $800 in summer, about $700 if they can leave in April, May or October. (After that, prices fall substantially on all carriers, along with temperatures and traffic levels.) Some U.S. carriers are running similar programs, too, but often with lesser discounts or more limited travel dates.

If you could benefit from one of these programs, it pays to ask your travel agent or reservationist specifically about them; they haven’t gotten much attention. When I called American Airlines to ask about details of its offer last week, a reservationist confessed that “this is the first I’ve heard of it.”

There are restrictions on all these fares, of course, beginning with the usual “subject to availability” clause. But most of the restrictions aren’t too demanding, so long as travelers qualify in the first place. It is possible that contemporary fare wars among the airlines could undercut these discount programs, yielding better prices for all travelers. Until last Friday, for instance, several airlines were offering highly restricted springtime round-trip fares for as little as $498 from LAX to Paris. But that was for dates of very low demand. The best regularly scheduled round-trip LAX-Paris prices will jump to the neighborhood of $900 beginning with June departures, and likely will remain there until demand wanes in late September. (Those prices, and the fares quoted below, exclude $25-$30 in airport taxes on each ticket.) Deep summer discounts are highly unlikely, which means that for those who qualify, the D-day specials may be the best deals around. Some details:

The Air France offer (tel. 800- 237-2747), available throughout the year, requires that travelers show proof of World War II service (generally discharge papers, separation documents or a DD-214 Form from the federal government). Restrictions include 30-day advance purchase, a stay of seven to 21 days, and travel Monday-Thursday. For travel April 1-May 31 and Oct. 1-31, the price of a round-trip LAX-Paris ticket is $683 (30% off the starting price of $976). From June 1 through Sept. 30, the price is $771 (30% off the starting price of $1,102).

At British Airways (tel. 800-247-9297), the D-day special is available to any traveler over 60 and one companion age 55 or older. As with Air France, the discount is 30% from regularly scheduled prices, and could in theory be undercut by fare wars. The best fare for travel from L.A. to Paris, April 1-May 31 and Oct. 1-31: $706 (discounted from $1,006); for travel June 1-Sept. 30, $792 (discounted from $1,132). Restrictions include 30-day advance purchase, a stay of seven to 21 days and travel Monday-Thursday.

At American Airlines (tel. 800- 433-7300), the D-day special applies only to departures from the carrier’s gateway cities (Chicago, Dallas, Miami, New York and Raleigh-Durham, N.C.). The American offer is open to World War II veterans with proof of service who can bring along up to three immediate family members or grandchildren at the same reduced fare. As with the other programs, the American D-day special offers 30% off on selected fares throughout 1994, but the numbers don’t pencil out as affordably as the European carriers’ do. For a round-trip ticket to Paris from Dallas (the nearest American gateway to Southern California) between April 1 and May 31, America’s best D-day-discounted fare is $796. From June 1 to Sept. 30, the figure rises to $916. Restrictions include seven-day advance purchase, a stay of seven to 180 days and travel Monday-Thursday.

Delta Airlines (tel. 800-241-4141) opens its D-day offer to Word War II veterans (or their widows) and three immediate family members--but isn’t offering its best discount during the most-sought months of June to September. Delta’s best D-day rate is $683, for travel May 1-31 and Oct. 1-31. Restrictions include 14-day advance purchase, stay of seven to 60 days, travel Monday-Thursday. Delta’s other D-day offer, good for restricted round-trip travel from LAX to Paris or Nice from April 1 to Dec. 17, is $1,016.

At TWA (tel. 800-892-4141), the D-day discount fares, available to WWII veterans and up to three family members, begin at $866 for travel April 1-May 31 and Oct. 1-31 (restrictions include seven-day advance purchase, stay of seven to 90 days, and travel Monday-Thursday), and $969 for travel June 1-Sept. 30.

Reservationists at Continental, Northwest, United, USAir, Virgin Atlantic and Lufthansa said their airlines had no D-day discounts to France now available.