Boston — Last month CP Air, a Canadian airline, tested a new gimmick on passengers flying between Vancouver and Amsterdam. For $3.50 a special game tray was slipped over the fold-up airline table, and during the nine-hour flight, passengers could blip and zap their way through six video games. While Donkey Kong and Snoopy Tennis were offered, other popular games such as Space Invaders were not.
''Anything with bombs, sharks, and parachutes . . . were weeded out,'' said Richard J. Theriault, director of operations for Altus Corporation, one of two firms involved in the market test.
Presumably, Donkey Kong at 30,000 feet is exciting; Astro Fighter (and any other games that shoot down flying things) is considered risque.
The Canadian airline's test is an example of airline caution in moving high technology into the passenger cabin. But airline and technology sources predict that as early as this fall airlines will begin offering new levels of passenger service. In the next three weeks, Altus plans to send samples of its video-game package to five major airlines.
Systems now in the works will allow passengers in midflight to:
* Reserve airline seats, hotel rooms, and rental cars.
* Telephone their homes and offices.
* Have access to world news, stock quotes, and other information services now available on the ground.
On Monday, American Airlines began showing the CBS Morning News on up to 100 flights daily. The show is taped, then video cassettes are brought aboard and broadcast on the jetliners' movie screens.
But the big stride, say people associated with the technology, would be a passenger-cabin computer terminal linked to the airline's ground-based computer network. Technologically, this is already possible.
Later this month, Pan American World Airways will begin a 90-day test of such a system developed by the Transcom division of Sundstrand. The airline doesn't plan to install any type of data-link system before 1984, says Pan Am spokesman James A. Arey. But he and industry observers see tremendous possibilities for the passenger.
''It'll offer a tremendous level of new service,'' says Jack Sharrow, manager of technical marketing for Bendix Air Transport Avionics Division, which also has a cabin data-link system. ''Our only limitation is what the ground computer can't do.''
Observers say the computer link will tell flight attendants where passengers are seated, which ones order special meals, and which passengers are frequent fliers. Pan Am envisions offering such services as up-to-date currency conversion and flight scheduling.
It is also anticipated that a passenger in danger of missing a connecting flight could make alternate reservations in midair, said Rick Climie, senior director of industry activities for ARINC. ARINC is the airline-owned company that runs the nationwide network of ground stations that make in-flight computer links possible. Other observers say passengers eventually may be able to book hotel and car rental reservations, although this is still a gray area in the Federal Communications Commission (FCC) interpretation of existing regulations.
Delta Air Lines soon will install an improved Bendix data-link system in the cockpits of its new Boeing 767s, with the capacity to hook up the passenger cabin. But so far no airline has committed itself to doing that.
That may change as early as next fall, these sources say.
''Each one is waiting to see what the other guy does,'' Mr. Sharrow of Bendix said. ''When one guy commits, it'll start an avalanche.''
Already, several airlines are preparing to try out another ground-to-cabin link.
This fall Airfone Inc., a joint venture of Western Union and Goeken Communications Inc., plans to try out air-to-ground telephone service for 10 major US airlines. On a wide-body or long-haul flight a passenger could dial directly any location in the United States, including Alaska and Hawaii. The cost: $7.50 for the first three minutes, $1.25 for each additional minute.
If the FCC finds that in-flight telephones are useful to passengers, it may make such services permanently available.
Eventually, said Mr. Theriault of Altus, ''what we envision is airline seats becoming complete home entertainment centers.''