The U.S. Court of Appeals ordered a new trial yesterday to determine whether the Good Humor Corp. was at fault in 1981 when a 3-year-old girl was fatally struck by a car as she crossed Benning Road NE to buy ice cream.

The opinion by a three-judge panel reversed a decision made during a trial two years ago by U.S. District Judge Thomas Penfield Jackson, who held there was insufficient evidence to let the question of the company's liability go to the jury.

Good Humor "knew or had special reason to know of the peculiar risks to children inherent in the street sales of ice cream and took absolutely no precautions to warn its vendors," the appeals court said in ordering a retrial.

William N. Rogers, the lawyer for Willis and Rosita Wilson, parents of the victim, said yesterday the case is the first so-called "Pied Piper" issue to be decided by the federal appeals court here.

The "Pied Piper" concept refers to vendors who "create an attraction that causes children to lose their sense of caution," Rogers said.

Attorney Thomas M. Wochok, who represented Good Humor, said the company would have no comment until it has studied the opinion.

The incident occurred after dark on June 24, 1981, when a vendor parked his truck in the 4500 block of Benning Road and began ringing "the distinctive Good Humor jingle bells," the court said.

As 3-year-old Tomikia Wilson started to cross the street, several children shouted to her to return to the curb. She was struck by a car and died 11 days later.

The court said that for 35 years, Good Humor had conducted an extensive safety program for its drivers. In 1980, however, the company changed the status of its vendors to independent contractors and stopped the safety effort.

Under D.C. law, an employer generally is not considered liable for physical harm caused by an independent contractor. But the liability law "bristles" with exceptions, said Judge Patricia M. Wald, author of yesterday's opinion.

Wald said the street sale of ice cream may be "inherently dangerous" under some circumstances and may be found to present "peculiar risks" for which an employer can be held liable.

An area sales manager for Good Humor testified, Wald noted, that "after 1981, Good Humor neither warned its vendors of the known peculiar risks nor took any safety precautions whatsoever. . . ."

Although the company had "special and detailed knowledge" of the risks to children, Wald said, "Good Humor has apparently chosen to disclaim responsibility for warning its vendors or for taking any precautions whatsoever against the known and specific dangers to children who purchase ice cream from their vendors . . . .

"Good Humor cannot insulate itself from liability in its own field of business when it engaged vendors to sell Good Humor products from the curbside . . . and flatly refused to take any steps designed to minimize those risks. . . ."

Judge Harry T. Edwards joined in Wald's opinion.

In a separate opinion, Judge Robert H. Bork agreed that the liability issue should be decided by a jury, but argued that Good Humor's obligation should be specifically limited to a "duty to warn" its vendors.

Without spelling out the firm's duty, Bork said, "we may find the trial judge's [jury instructions] inadequate even after this case has been tried, which would lead to a second reversal and yet another trial."