Mayor W. Wilson Goode's account of what he knew about planning and execution of the police assault against the radical group MOVE was challenged today before a commission investigating the incident.

Leo Brooks, the city's former managing director, said that Goode was briefed at least twice on plans for the May 13 assault and that the mayor approved dropping a bomb from a helicopter on a row house occupied by MOVE members and children.

Goode told the panel Tuesday that subordinates misled, misinformed and disobeyed him during the daylong confrontation that resulted in a widespread fire, the deaths of 11 MOVE members and destruction of 61 houses.

Brooks, Goode's top aide during the incident, contradicted the mayor on several key points. He said Goode was told that explosives would be used in the assault and that a bomb would be dropped on the row house from a helicopter. Goode had said he was not told about either.

Brooks said he is "positive" that he told Goode about the helicopter in a phone conversation about 30 minutes before the bomb was dropped at 5:29 p.m. "It's also possible he didn't hear it," he added. "I said there would be a helicopter."

"There was a short pause, and the mayor said okay," said Brooks, who resigned "for personal reasons" after the MOVE confrontation.

Brooks said he shared Goode's frustration in trying to extinguish the fire that followed the bombing. Goode testified that he did not take an active part in planning the assault until a few minutes before 6 p.m. when he ordered Brooks "to put the fire out." That order, he said, was disobeyed by Police Commissioner Gregore J. Sambor.

Brooks, who had watched from a rooftop three blocks away as flames leaped from the MOVE compound to adjoining row houses, said he had already told Sambor "let's get the fire out."

Communications apparently broke down. Brooks said it took him four to eight minutes to reach Sambor. He said that he saw water being sprayed on the fire within a few minutes but that it soon stopped.

Unable to reach Sambor a second time, Brooks said he rushed to the scene. By the time he arrived, he said, firefighters were dragging hoses toward the MOVE house. He said they retreated when police reported gunfire from the rear of the heavily fortified house.

Brooks said that the ensuing hours were harried and frustrating and that, at one point, he joined the firefighting effort. He said he repeatedly told others that night, "We let the fire burn too long."

Later, he said, "I believe today, if the fire could have been put out, it the bombing would . . . not have been lethal. I believe no one was hurt by the explosion itself. Its only ugliness was the political implication of dropping the bomb."

Brooks said he subsequently learned that Sambor ordered a halt to firefighting efforts because steam was obscuring the view of police surrounding the house and because Sambor wanted a rooftop bunker to burn.

Brooks indicated that he does not think that Sambor directly disobeyed the mayor's order to extinguish the fire.

He said he does not think Sambor or Fire Commissioner William Richmond "is enough of an animal to do that."

When crucial planning for the assault occurred, Brooks was in Virginia attending his daughter's college graduation, and he said he first learned about problems in the MOVE neighborhood May 13 as he drive home to Philadelphia that day.

Brooks said Sambor briefed him on plans eight hours before the assault and said he relayed what he had been told to Goode, including the decision to use explosives.

Sambor had briefed the mayor earlier, and Goode "had already decided what he wanted to do," Brooks said.