Our family's 10-day trip to London over Christmas began one night last July when my daughter asked if we could do something special for a family vacation. She reminded us that December was a month of birthday mile-stones: her father's 50th, her brother's 21st and her 16th.

Her idea of something special was a trip to Europe. It seemed like a good idea if we could keep the cost down, which meant finding a charter flight that would go where and when we wanted to go. If we knew then what we knew two months later, we might have gone to Mexico instead!

We were flexible about our European destination but we could not leave until my son had finished his exams on Dec. 23. We didn't want any land arrangements - hotels, bus tours, theater tickets - that accompany most charters. But we weren't sure where to turn for information.

We sent for two books I had read about in New York magazine that are devoted to charter flights. The almost 21-year-old, Michael, was put to work calling travel agencies and airlines several travel writers were consulted. All of them said the same thing: There is no single source for that kind of information and you'll have to start calling around.

The two books, "Good Deals on Low Cost Charter Flights and Tours" and "Jens Jurghens 1976 Charter Flight Directory" arrived about a month after they had been ordered and were eagerly scoured for a flight leaving on Dec. 23 from Washington.

NOTHING - No matter how many times we read pages and pages of listed flights.

"Good Deals" listed no flights out of Washington-Baltimore to anywhere in Europe except London after the early fall, and even for the height of the travel season it listed very little from this area.

The "Charter Flight Directory" offered a little more hope. It showed United Buying Severice with flights out of Washington to London through Jan. 9, but when its brochure arrived we found its December flights were either too early or too late.

A travel writer friend suggested we contact Beeson. Travel Bureau in Washington, but its brociure was equally disappointing: The Last December flight left before we could.

Meanwhile I kept combing the office bulletin boards because the recreation association offers frequent charters - but none to Europe in December. I also copied names of travel tour agents from other charters offered and contacted all of them. Still nothing. It seems that everyone from this area goes either to the Caribbean or Las Vegas in December.

Michael's phone calls to two airlines produced some incomplete and misleading information: that in order to take advantage of the lowest fares we would have to go for at least 21 days. So we stopped pursuing that course and relucantly concluded that the only way let for us to go to Europe would be to fly from New York. In the meantime, just to cover ourselves, we made reservations to fly to Mexico. This was six weeks and at least 40 telephone calls after our original dinner table convesation. Only later did we learn there were some airline charter flights from Washington for two-week periods. By that time we had already paid our deposits on the flight we would evenually take out of New York.

"Good Deals" listed one flight on Laker Airlines from New York on Dec. 23, which was for air transportaion only. I had never heard of Laker and was a bit spertical as I envisioned what had happened to many charter participants in the past - carcelled flights, lost money, stranded presengers. (Of course, in many cases those were illegally bookers flights with no provisions for payments being placed in escrow accounts.) But a travel writer friend assured me the airline was as good as the ones with better known names.And as a British journalist was to remark later: "Later? Oh Yes. They're just like everyone else - once they get off the ground."

We discovered what he meant when our flight from New York was delayed seven brurs because the plane was late leaving London due to fog (that's what is meant by "back-to-back charter") and two hours late returning because it couldn't get a assignment and then couldn't get the engines started.

Such problems are typical of charters and only the tremendous saving in fare makes it worth the trouble. The four of us flew to London and back for less than what one first-class unrestricted ticket would cost. Each person paid less than half of a regular offseason excursion far. Our fares were $293 each including taxes and service charges.

But it wasn't easy. Finding a charter flight that leaves when you want to leave and goes where you want to go, understanding the varieties that are currently available; knowing how long you must book in advance, what the chances of a higher rate are if the plane isn't filled, and about the possibility of cancellation because too few people signed up - it is all incredibly confusing and time-consuming and there is no one single source for such information.

Various booklets have been put out explaining the alphabet soup of charters: Travel Group Charter (TGC) which is round-trip air fare only with a minimum of 10 days stay in Europe and the one we took; Inclusive Tour Charter (ITC) which must make at least three stops and includes land arrangements with a seven-day stay minimum; One-stop Tour Charter (OTC), which includes land arrangements and a minimum of seven days in Europe. But there is no single source that lists all the available charter flights.

All this confusion may end within the year. Two events, slowly making their way through the bureaucracy of this country and the English courts, could dramatically alter overeas flying.

One would chage the complexion of charters entirely; the other would make flying - at least to London - almost as easy as shuttling to New York, and just as cheap as the charter we took.

The first is a Civil Aeronautics Board (CAB) Plan called Advance Booking Charter (ABC), which will allow you to sign up for a regularly scheduled flight only 45 days before departure for European destinations, instead of the current 60 days for TGCs, and to stay for as few as seven days. No land arrangements are required. The price would be competitive with current TGC rates.

The CAB says the ABCs are in operation to some places already, but it doesn't seem to know exactly where. Some opposition from Britain is expected: It may insist on a minimum two-week stay.

The other development is the recent victory of Laker Airways in its fight with the British goverment over operation of Skytrain. The Skytrain concept would allow an individual flying the London-New York route to purchase a ticker no earlier than six hours before departure and just walk on the plane. The suggested fare currently is $230, but would probably go up to the same as the regular Laker NY-London charter fare. The biggest drawback to Skytrain is that those who arrive to purchase a ticket after all the seats have been sold must wait for the next day's flight.

In December, the airline's owner, Freddie Laker, won the fourth round in his battle with his government. While the government might make a final appeal to the House of Lords, a Laker official said it is unlikely that it will because its chances of winning are very slim.

The judge who handed down the most recent decision reminded Her Majesty's lawyers about their batting average in tennis language: "You realize," he said, "it's four-love already, don't you."

Laker still has another hurdle: the U.S. government. The CAB has charged its position on Skytrain several times, but with a new administration promising deregulation, CAB may look favorably on the shuttle service.

American will have to hurry if they want to find any bargains left in London. Whatever you may have read about Europeans, Japanese and Arabs flocking there to buy in truckloads is absolutely accurate. The streets are clogged with traffic; the store shelves are low on many items. In addition, while prices on most goods are a bargain for Europeans, only a few things are good buys for Americans at current prices.

Besides, when England goes to buy new higher priced materials, costs for finished goods are likely to skyrocket and men's shirts that sell for $40 in America will no longer be $22 in London.

So we saved a lot of money by not spending it and whatever hassle was involved in getting to Europe was worth it all. A family trip with children did enough to go about on their own, but still willing to do some things with their parents is one of the most delightful and memorable expericences we have ever had. It was a terrific birthday party!

Burros is Fodd Editor of The Washington Post.