The Cambridge School Committee voted 5-1 last night to continue the Cambridge Pilot School at least through June 1971.

The Pilot School is an experimental high school operated by the Cambridge School Department and the Harvard Graduate School of Education.

Now in its second year, the school is housed in Rindge Technical High School and has an enrollment of 120 students, who represent a cross-section of the Cambridge community.

James Fitzgerald, one of seven School Committee members, lambasted the Pilot School for its damaging encroachment on the two existing high schools, for the "filthy conditions" in the classrooms, and for its toleration of "inflammatory literature" such as SDS, SMC and Black Panther leaflets.

Speaking before more than 300 persons gathered for the special meeting in the Rindge auditorium, Fitzgerald presented several poster-size photographs of the classrooms to document his charges.

The Pilot School, he said, is "breaking down the spirit and minds, brain-washing our kids."

Friends of the Pilot School, including staff, students, and their parents, spoke up exuberantly in its defense. They did not deny the strained relationship between the Pilot School and the rest of the system, not the untidy appearance of the classrooms.

But those are things to be improved, they said, not reasons to disband a viable experiment in innovative, community-involving education.

Harold Broadley, a Pilot School parent, praised his son's "freedom to learn there, freedom to learn everything." Then, he said, "kids can make their own decisions."