The Metropolitan Washington Airports Authority has launched an audit of the troubled taxicab system at Dulles International Airport aimed at settling a dispute over how much drivers earn.

Spurred by Washington Flyer driver claims that they are struggling to make a living wage, and the company owner's assertion that they earn close to $65,000 annually, the authority, which operates Dulles, has set out on its own fact-finding mission.

Some drivers have complained that Farouq Massoud, who runs the Washington Flyer cab service at Dulles, has added so many cabs that there aren't enough customers for individual drivers to make money.

"The drivers have raised the issue that they are not getting a substantial number of dispatches. We would like to get some documentation of what the actual fact is," said Tara Hamilton, authority spokeswoman.

The audit comes as the contract for being the main provider of cabs at Dulles is up for bids, and several groups, including a Washington Flyers drivers association organized this year, are expected to make proposals by the Dec. 10 deadline.

With facts in question concerning the numbers of trips cabbies make each day and their earnings, the authority decided to undertake its own investigation, so that potential bidders will know what they will be expected to provide, Hamilton said.

Relations between Massoud and the 472 drivers of the distinctive gray Washington Flyer fleet began deteriorating in March, after Massoud fired drivers on two occasions, and the drivers staged sit-down strikes.

Drivers have complained that their expenses--including fees they are required to pay Massoud--are too high, and that their income is too low.

As part of their audit, authority staffers are monitoring Washington Flyer's dispatching operations, Hamilton said, to see how trips are assigned and recorded.

The authority also has requested the computerized records kept by Massoud that show how many trips have been dispatched for each driver. The authority is also seeking the manifests of 25 randomly selected drivers on 12 random dates over the last year.

"We want to compare the contractor's records with [the] randomly selected cabdrivers' manifests," Hamilton said.

Massoud said he would comply with the authority's requests. He declined further comment.

Massoud has said that each driver makes about eight trips a day, with an average fare of $35, for a daily gross income of $280, and an annual gross income of about $65,000. Many of the drivers dispute those numbers, claiming that they average seven trips per day, often to nearby locations such as Herndon or Sterling. The average fare is $20 to $25, they say.

Drivers claim they must work 14 to 16 hours a day just to get seven trips anywhere. Some drivers say they work round-the-clock, seven days a week, and sleep in their cars, so as not to miss any fares. Their annual expenses, including insurance and car payments, run $30,000 or more, leaving them with a take-home wage between $10,000 and $20,000, the drivers said.

Drivers learned of the audit last month when Massoud posted a notice that 25 drivers had one week to provide all their daily manifests from September 1998 to August 1999. Initially, the drivers resisted, saying the requirement for a whole year of manifests was unrealistic.

After the authority clarified to drivers that only 12 days of manifests were sought, and that audited drivers were randomly selected, the drivers agreed to provide the information by Nov. 29.

"We're okay with it," said Abdalla Nasir, head of the drivers' association.