Dallas Hickman was roaming toward the middle of the field from his linebacker position the other day when a sassy rookie quarterback looked in his direction and tried to loft a pass over his head to a cutting wide receiver during a seven-on-seven drill.

The quarter-back is sassy no more. As the ball left his had, Hickman coiled his 6-foot-6 frame and leaped high in the air. His outstretched hands tipped the ball, and as he returned to earth, Hickman caught it for the interception.

On the next play, another rookie quarterback aimed a throw at the running back Hickman was covering, and his pass was swatted down by the tall blond man trying to make the switch from defensive end to linebacker in his fourth NFL season.

Judging from the smile on the normally placid face of coach Jack Pardee, a fellow who once played linebacker himself, Hickman already is succeeding.

For Hickman, there will be plenty of opportunity during this first week of training camp to demonstrate to Pardee and the coaching staff that he can make the adjustment from down lineman, the position he played the past three years, to a linebacker in the image of Ted Hendricks, the "mad Stork" of Oakland.

Until Hendricks came on the scene, most NFL coaches thought tall people should weigh 275 pounds and rush the passer or, failing that, develop a 15-foot jump shot and try basketball.

Hendricks changed all that and people like Jack Lambert (6-4) in Pittsburgh. Kim Bokampen (6-6) and Larry Ball (6-6) in Miami and now, Dallas Hickman in Washington are grateful.

Pardee made the switch, no doubt drooling over the possibility of having Hickman available for the three-line-men, four-linebacker 34 defense he plans to install during camp, and use extensively during the regular season.

The Redskins worked on the alignment today for the first time in camp, and probably will use it Saturday in Annapolis against the Colt rookies.

Even though he could seldom get the scales to tip past 235 pounds, Hickman always demonstrated he could rush the passer when George Allen allowed him to play defensive end during the last three exhibition seasons.

Now Hickman is trying to show that he is swift and rangy enough to cover a man coming out of the backfield on a pass pattern andrugged enough to take all those nasty shots linebackers on the run must endure.

Hickman is getting a lot of work, mostly because there are only six linebackers in camp. That total will swell to 11 when the veterans report on Sunday and Hickman would love to make a strong impression against the Colts to keep the coaches interested.

'I'm just really enjoying the position, it's a lot of fun," he said yesterday. "I've been trying to find a place to play ever since junior college, I played split end and tight end there, then tight end and defensive end at Cal. But I think this is it, this is where I ought to be.

Pardee apparently agrees. "We've thrown a lot at him and he's picking it up right away," he said. "You work on something new with him and after a few times he knows what he's doing, and that's a good sign. This is an awfully awfully valuable camp for him because he'll get a lot of work."

Bobby Mitchell tried to convince Allen to switch Hickman's position almost from the day Hickman arrived in 1975, a ninth-round draft choice who didn't start a game in his senior season of college.

"But Dallas looked pretty good at defensive end, and you know how hard it was to make George change his mind about anything," Mitchell said. "He thought about it, but he'd never do it.

"A guy like that at linebacker gives the quarterback a real problem. You better throw it accurately or the big guy's gonna swat it down. It also makes it nice for the cornerback on that side because he knows that nothing short is going to sneak in there on him. That lets him play his own man tighter."

Doc Urich, the Redskin defensive coordinator, concerred. "Provided the guy has fluid movement and has range, and we think Dallas does, he can really give you an added dimension in that spot. When he comes up on the quarterback, the added height alone could force him to throw it just a little bit off. And that makes a big difference.

"Right now, he's doing very well. It's still very early, but he's a good kid and he works hard. He's getting a lot of good work now. He's got so many new experiences he's got to face, so it takes time and repetition to get it down. But we like his progress."

Hickman also knows that he is being counted on to play on the Redskin special teams no matter what happens with the linebacking experiment. The last two years, he was among the most valuable members of the bomb squad, a tackling terror on the kickoff defense team with a penchent for busting wedges and rocking return men.

That sort of murderous mayhem seems totally out of character for Hickman, an introspective young man who lives on a small farm in Leesburg, Va., likes to grow vegetables in the garden and looks horrified when someone suggests he adapt the nickname "Stork Two."

"Nah," he said. "I'd just rather be Humble Hickman."

The linebacker.