Though he only plans to stay on as head of the Chicago Public Schools for six months, interim CEO Terry Mazany laid out a dramatically different course for schools Monday, saying that under No Child Left Behind “we’ve traded off our pursuit of excellence for the tyranny of accountability.”

Mazany said the focus has been on failing schools and all that encompasses, including firing bad teachers and principals and closing schools.

By doing so, we’ve ignored the 80 to 90 percent of schools that are good, and lost opportunities to make them great, Mazany said.

“If…we think about schools as needing to improve—not needing to be closed—then we focus the system’s resources on support and development,” Mazany told civic and business leaders at a speech at the City Club.

January is the month when the school district typically announces school closings, which teachers and parents from some schools have fought bitterly. Mazany said CPS hasn’t determined a timeline for closings—but he didn’t rule them out

In fact, he said Chicago would have to address declining enrollment. Over the past decade, Chicago schools have lost about 20,000 students. But the system has been adding schools, many of them charters. Mazany says Chicago needs to do a comprehensive facilities inventory —and make the case to parents that some schools should be closed.

“Every building represents dollars in bricks and mortar that could go to dollars in the classroom for student instruction,” he said.

Mazany was appointed by Mayor Richard M. Daley to head the schools in November and is on loan from his position as head of the Chicago Community Trust.

Much of Mazany’s address focused on the United States’ position globally in terms of economic output and educational attainment. He said global competition demands that schools that have been inching forward now “leap frog” to become the right schools for the time we live in.

That means restoring a full dose of arts and civics, Mazany said. “We so narrowed the curriculum focus, that we lost the essence of our education system.”

And he took a swipe at standardized testing, saying “you can’t fatten a chicken by weighing it.”

After his address, Mazany hinted he’d support controversial legislation in Springfield that would limit teachers’ right to strike.

“So many of our students count on schools for their nutrition, for safe environments, for enrichment. … we would put a lot of young people at risk if we were to have to close schools for a prolonged period of time,” Mazany told reporters.

Chicago’s last teachers strike was in 1987.

But Mazany said his first priority is to secure more state funding for Chicago schools. He called last year’s round of budget cuts “brutal” and said a repeat would be “devastating.”