The Alexandria City Council has left Sheriff Michael E. Norris' proposed airborne prisoner shuttle up in the air.

By a 4-to-3 vote late Tuesday, the council gave preliminary approval to the sheriff's plan for a regional air transport system that would transfer prisoners between local prisons and facilities in central and southern Virginia.

But the council drew the line at agreeing to take title to the plane that Norris says the U.S. General Services Administration would give to the city for free. The plane is a twin-engine Cessna 402 that was confiscated from drug runners in Miami.

The council said it wanted a cost analysis of the sheriff's prisoner shuttle before it would grant Norris his aviator's wings.

"I don't think he has any idea what the costs are," said council member Donald C. Casey, a frequent critic of Norris. "First, we have an over-capacity jail, and now he wants to get into the transport business. I think it was a mistake to encourage him on this."

Casey also questioned the security risk posed by 10 prisoners on one plane. "It wouldn't be the first time he's had a prisoner take over his guards," Casey said.

Norris estimated the yearly upkeep cost of the plane at $21,000. The plane would eliminate the need to buy two new vehicles to transport prisoners next year, he added.

Alexandria's costs would be offset by other Northern Virginia jurisdictions willing to fly their prisoners to the downstate prisons, Norris said. Sheriffs in Fairfax, Arlington and Loudoun counties have expressed interest in the proposal, he said.

"We were the first agency to get a microcomputer -- now there's no agency in the city that doesn't have one," said Norris. "There's always a little bit of flak with pioneering innovative efforts, and I am fully capable and willing to take the flak."