At 9:50 a.m. yesterday, there were two dozen people lined up, luggage and briefcases in hand, patiently waiting for a taxi at Washington National Airport's main terminal.

There were several cabs at the airport, but they weren't in the taxi lane. They were circling in outer lanes, some of them with simple signs taped to their windows saying: "FAA Unfair to Cab Drivers."

The cabs with the signs complaining about the Federal Aviation Administration were engaging in work slowdown yesterday to dramatize their unhappiness with various work rules at the FAA-operated airport.

The three-hour morning slowdown appeared to have mixed results. While the customer line at times grew to as many as 25 people, few travelers had to wait long for a cab - mainly because the taxi dispatcher squeezed as many people as possible with similar destinations into each cab.

The action the taxi dispatcher was forced to take would have satisfied one of the taxi drivers' demands. They want to be allowed to carry more than one passenger during rush hour, contrary to airport rules.

The slowdown was organized by the Professional Cab Drivers CB Club. Its president, Joseph Bradley Sr., sai the drivers also are demanding that the FAA build a parking lot or holding area nor cabs so that when hackers outnumor passengers, the driver can stop his car in the lot and lit to re-enter the cab lane, rather than wasting gas by con tantly circling around the iepoer sa.

Bradley said the group also wants bathroom facilities for the hackers, and they want the police to stop giving out what he called "unnecessary" tickets to cab drivers.

An FAA spokesman said the "one passenger to a cab" rule was implemented about 1 1/2 years ago. The cab drivers previously had been allowed to transport several riders in their car because the FAA thought it would help in the energy crisis.

"But we got all kinds of complaints from people." the FAA spokesman said. The cabs "were crowded and sometimes there were people with three different destinations in the cab. Businessmen coming to town paying extensive cab fares want to be taken to their hotel or office immediately."

He said it also became hard for drivers to compute fares, generating arguments between customers and drivers. There is a sign at the airport taxi stand stating that only one passenger is allowed to a cab, unless the group is a performed party going to the same destination.

The FAA spokesman said the airport manager is considering the cab drivers' complaints and demands. He said he did not know how much it would cost to build a cab holding area.

Bradley said that if the drivers' demands are not met within a week or two, he may call an "all-out strike" asking cab drivers to stay away from the airport entirely.

One taxi dispatcher said the slowdown yesterday caused little problem because there was no rush of passengers needing cabs. He patiently told travelers about the work slowdown, and suggested they either use the bus, limousine service or flag a taxi outside the cab lane. Several passengers bypassed the dispatcher, trying to find their own cab by shouting their destinations to drivers eager to fit as many people as possible into their cars in violation of the normal rules.

Most passengers seemed to take the temporary lack of cabs in stride. One man jokingly said, "I get to Washington once in a blue moon and I get a cab strike."

The taxi dispatcher said on a normal morning, he might have 50 cabs in the taxi lanes picking up passengers and he said he usually can move 100 people in from five to 10 minutes. Sometimes on Fridays, the drivers get backed up so much that they have to wait more than an hour for passengers, he said. Yesterday morning, during the height of the slowdown, there was only a trickle of cabs pikcing up customers.