One thing that district and charter schools have in common is a need for strong principals.

That’s what James Merriman, a lead advocate for the city’s charter sector, told Gov. Andrew Cuomo’s education reform commission on Thursday.

“Charter schools understand and public school leaders understand that a successful school culture is ultimately the responsibility first and foremost of a school leader,” said Merriman, who leads the New York City Charter School Center.

“But here’s the tricky part,” he said. “We don’t have enough of them. We don’t have enough of them in the charter sector; we don’t have enough of them in the public schools.”

The Bloomberg administration tackled principal preparation in one of its earliest education initiatives, a training program called the Leadership Academy. But the program’s graduates have ranged in quality, with some leading successful schools and others being criticized for creating dysfunctional work environments. The program has shrunk over time, and in January, a top Department of Education official told a group of principals who are affiliated with Teachers College’s Cahn Fellows program that the city has not succeeded at maintaining uniformly strong principal quality .

The problem of where to find strong school leaders is more acute in the charter sector, where principal turnover is five times higher than in district schools.

Merriman told the commission he had no concrete solutions for boosting principal quality. But he believes that an annual principal training program that his organization runs, which begins next week, could at least begin to chip away at the problem.

The yearlong program, called the Emerging Leader Fellowship, seeks to identify top-tier teachers and groom them to take leadership roles at their school. Of the 40 teachers who have gone through the program since 2007, 80 percent have been promoted to leadership positions, according to the Charter Center.

Merriman said the program is specifically meant to support independent charter schools in New York City because, unlike charter management organizations that operate networks of schools, they can’t afford leadership training programs.

“They have their own emerging leaders programs,” Merriman said of the CMOs, which in recent years have set the charter sector’s policy agenda. “This is a program that helps the independent schools that can’t possibly have that support.”

This year’s eight candidates come from five charter schools: Bronx Charter School for Excellence, Bedford Stuyvesant New Beginnings Charter School, New York Center for Autism Charter School, Hyde Leadership Center, and Renaissance High School for Innovation.

In some ways, the program is modeled after the growing teaching residencies, which prepare teachers by mixing lessons of theory with large amounts of time teaching in a classroom. The fellows will meet regularly over the school year to learn about how to manage a budget, hire and train top teachers, and create accountability systems. They’ll also get mentoring from their current principal, an arrangement that Merriman said requires school leaders to buy into the idea that the teacher should one day take on additional responsibilities.

Merriman said the program is not specifically designed to address the high rate of principal attrition in the charter sector. But he said that the high-quality leaders that he hoped would come out the program would be better prepared for the job and, as a result, stick around longer.

“Obviously, it’s common sense that for leaders who are well-equipped and trained, the job is something that they can stay in and do for longer,” Merriman said.