There was never a dull moment in "The Rescuers", the delightful animated feature released last summer by the Disney studio. "Pete's Dragon," the Disney Christmas attraction, now at area theaters, represents a total relapse into the kind of semi-comatose beamishness that the company frequently confuses with wholesome entertainment.

"Dragon" never come close to the sprightly pace, lyric charms and cliffhanging thrills of "The Rescuers." At 134 minutes, the new film, which inserts an animated character into some live-action sequences, is almost an hour longer. "Dragon" was apparently meant to be a big, rousing musical comedy-fantasy, but its' staged and photographed withour musical-comedy energy, flair or coordination.

For example, Onna White supervised the dancing and her style is instantly recognizable, but her ensembles do not have the rhythmic or pictorial charge they did in "Oliver!" where a director like Carol Reed and a photographer like Oswald Morris obviously knew how production numbers should be visualized and cut for the screen.

Don Chaffey, the director of "Pete's Dragon," is an Englishman who usually handles juvenile melodramas like "Ride a Wild Pony" for Disney.I'm not aware that he ever directed a musical, and "Pete's Dragon" is devastating evidence that he doesn't know where to start.

The story, purchased many years ago by the company, is set in the Maine seaside community at the turn of the century and concerns the efforts of an orphan to find refuge from an adoptive family of mean yokels and to persualde people that his playmate, a ponderous, goofy-faced dragon named Elliott, who can make himself invisible, is not a figment of his imagination.

The movie gets off to a promising start when Sean Marshall, the snubnosed, freckle-faced juvenile lead flies onto the screen - the invisible Elliott is giving him a ride. The promise fades as Shelley Winters, cast as the yokel matriarch, and her cohorts lumber through the opening song. It fades even more when the animated Elliott materializes and you see what the Disney folks are not trying very hard to combine live-action and animation in an irresistible way. If anything, the combination seems to wash out the color, leaving you with a pale green cartoon figure superimposed on pale live-action settings and locations.

There are plenty of troupers in the cast - Helen Reddy as the lighthouse keeper's daughter who takes Pete in, Mickey Rooney as her tipsy dad, and Red Buttons and Jim Dale as a team of confidence men. However, none turns into a picture-saver, due in considerable part to the grinding inanity of the songs supplied by Al Kasha and Joel Hirschhorn.

Chaffey also seems oblivious to his most valuable trouper, Rooney, the only one in the cast who has ever carried a musical sequence, not to mention a whole movie, gets shunted aside after introducing one number, while Dale and Buttons are permitted to wear out their welcomes with two interminable movelty songs.

Perhaps children can be counted on to enjoy Elliott's mugging and the slapstick interludes that occasionally interrupt the tedium, but parents will see this more as a chore.