A one-hour fantasy-drama produced by WRC-TV in association with the Educational Film Center of Annandale airs on the NBC network today as this month's "Special Treat" for young viewers. "Out of Time," at 4 on Channel 4, is a time-travel adventure about two Frederick County, Maryland, youngsters who travel to 1851 and prove that an ancestor was not a slaveholder and not a crook.

Adam Baldwin, the bodyguard of "My Bodyguard," plays the ancestor, Otto Frommer, whose trunk the children find stashed on their farm. A terror of a thunderstorm zaps them back to a pivotal moment in Otto's career. The kids had found a receipt for two slaves in the trunk, but this incriminating evidence turns out to be misleading. Otto was actually involved in a small-scale underground railroad. With the kids' help, he foils an evil slave trader and helps several slaves escape to freedom.

Unfortunately, though the subject of slavery is involved, "Out of Time" has no black actors in speaking parts. Black people are depicted either as the beneficiaries of white largess or as the victims of white venality, but not as dimensional characters. Authors Ruth Pollak, Ira H. Klugerman and Patrick Prentice should have written in at least one prominent role for a black actor.

Otherwise, everything here is shipshape and first-rate. In terms of production, the film is handsome and smart, well directed by Michael Schweitzer and impressively produced by Donald Fouser. There has been no apparent corner-cutting and there is a happy absence of kiddie-show condescension. Baldwin does his enigmatically stoic bit again, and effectively; as the two time-traveling tots, R.D. Robb is a stouthearted young man and Amy Locane a living doll with a winning manner.

The period scenes in "Out of Time" were filmed in and around Baltimore's Fells Point by cinematographer Tony Louis Cutrono, who got the most out of the locations. Everyone involved earned his kudos; the only pity is that there's a kudo or two left over for performances that should have been but weren't.