(FORTUNE Magazine) – ON THIS OVERCAST April morning, Marvin Starer, 58, the regular principal of Manual Arts High School in gritty south central Los Angeles, is wearing thick, sky-blue socks and rubber-soled walking shoes. Arco President Robert Wycoff, 59, who is acting as principal of the school for a day, soon finds out why: ''I circulate a lot,'' Starer explains as the two set off to cruise the playground, where Starer likes to hang out with students. Replies Wycoff: ''In the business world that's called 'management by walking around.' It's very effective.'' So begins one executive's exposure to a day in the life of an inner-city principal -- a day that includes classroom visits, frank talk with teachers, and a disquieting discussion with gang members. In all, over 40 local business leaders from such companies as GTE, Hughes Aircraft, and Bank of America participated in the Principal for a Day program, part of a week-long drive sponsored by the Los Angeles Educational Partnership to encourage business involvement with schools. One of Wycoff's first duties at Manual Arts is to address the English as a Second Language class that Arlene Andrews teaches. ''Mi espanol es malo,'' he begins, in an attempt to reach at least some of the teenagers, who come from Guatemala, El Salvador, and Honduras (not to mention Korea and Vietnam). Some 2,400 students, mainly black and Hispanic, attend Manual Arts; roughly 800 are recent immigrants. Wycoff quickly finds that language is not a problem: In just a year these kids have picked up enough English to converse fairly fluently. Their motivation to learn bowls him over. On this day teacher Jo Zarro is encouraging her English class to talk about the characters in A Catcher in the Rye and Of Mice and Men. A lively discussion ensues. Impressed with Zarro's energy and enthusiasm, Wycoff asks Starer, ''Do you reward her?'' The budget-constrained principal's answer: ''Praise is her major reward.'' Later, over a lunch of cold cuts and potato chips, Wycoff delivers a message to a group of teachers: ''Arco and other businesses are anxious to help you in any way we can.'' The staff is experimenting with shared decision-making in running the school and is eager for management advice. Several teachers complain about the long hours and the politics entailed in so-called site- based management, which gives them a say in scheduling and curriculum. ''It is very difficult to achieve change through committee,'' Wycoff tells them. His suggestion: Let teachers act as advisers on policy changes, then leave the execution of those changes -- the hard part -- to the principal. The day ends on a troubling note. Wycoff listens intently as students describe the gangs, drugs, and shootings that are part of their daily lives. Already this year Starer has attended funerals for three teenagers from the school. He tells the kids: ''Some of you will make it, and others won't. That's scary.'' Why do they join gangs, Wycoff wants to know. Parents who don't care, they tell him. Protection. Friendship. ''We're like family,'' says a female member of the 18th Street gang. ''If a gang member gets shot, it hurts us, so we have to do a payback.'' Mutters another, ''The killing's never gunna end.'' Wycoff finishes the session by asking what it would take to lure them away from street life. They answer readily: more extracurricular activities at school -- special Saturday classes, sports, dances -- and most of all jobs. ''We can try to improve ourselves,'' says a small Hispanic boy who seems a reluctant gang member. ''But we need help from people like you.'' BACK IN Starer's office, Wycoff reflects on the day. Oddly, he says, he feels more hopeful than when he arrived. The teachers were inspiring, the kids friendly, and the place more peaceful than he expected. The school's motto, ''It can be done,'' may seem a bit corny to outsiders, but Wycoff now understands that it means a lot to people whose world doesn't otherwise offer much hope. He also appreciates how much work it takes to manage an inner-city school. ''If I were principal of Manual Arts, I could not do as good a job as I saw today,'' he says. ''This is not as simple as going to the moon.''