Waving signs, chanting, and pumping fists in the air, more than 50 high school students gathered outside Philadelphia School District headquarters yesterday to air their concerns about a sweeping blueprint to remake city schools.

"Imagine 2014," Superintendent Arlene Ackerman's newly introduced strategic plan, calls for the district to shutter up to 35 failing schools and reopen them as charters or under outside management.

That worries Mason Tyer, 18, a senior at West Philadelphia High School and member of the Philadelphia Student Union, which organized the demonstration. He doesn't believe his school is hopeless, and he doesn't want the district to give up on it, he said.

"We need more help," Tyer said. "Doing this to us, we feel like we're being kicked to the curb."

Tomas Hanna, the district's chief of school operations, said it was too early to say which schools might be closed, and stressed that no action would be taken without input from affected neighborhoods and students. But allowing a failing model to continue is not acceptable, he said.

"This is not about displacing young people," said Hanna. "Our dropout rates are high, and achievement has been low in some schools. We have to do something to fix that."

Hanna said that he was pleased to see so many students turn out to air concerns about the plan. A group from the Philadelphia Student Union will meet with Ackerman today to discuss the strategic plan, district officials said.

Timothy Veal, 17, is glad to have the opportunity, but the Lamberton High senior is still wary of what could happen if a new crop of charter schools creates two school systems - one for people who can get into them, and one for the others.

According to the district, students who attend the schools that are to be closed will all be admitted to the new schools that replace them.

"Even though I'm a senior, I still care about what happens," said Veal, who wore a silver knight costume, held a cardboard horse, and brandished a plastic sword to dramatize the "false promises" of a Chicago plan some say is the basis for Ackerman's blueprint. "This is not fair."

Renaissance 2010, the Chicago plan, set out to close 100 struggling schools and replace them with 60 charter schools. Critics say the plan has pushed poor students out and that the new schools have not produced better results than traditional public schools.

Ackerman has said that she does not know much about the Chicago plan, and based Imagine 2014 on other reform models from around the country, plus district task forces, reports, and community input.

The students said they agreed with some parts of the plan, including a call for more counselors and an expansion of "student success centers" - resource rooms where students can get help preparing for college and dealing with high school.

Helen Gym, a founder of Parents United for Public Education, reminded the students that they had a chance to affect change, and asked them to press for it.

"This is a chance to do it right," Gym told the students. "We've got a chance to have students engaged, parents engaged, teachers engaged in the process."

When the state took over city schools in 2001, the district began using a "diverse provider model," handing over management of some public schools to outside groups, including for-profit companies. At the time, many felt that change was imposed on them.

Hanna said that would not be the case with Imagine 2014.

"This process is about engaging the community, hearing everyone's thoughts and concerns," he said. "We're going to look at lessons learned in the past."