But he knows too well that progress is still the exception, instead of the rule, at Locke. And such signs of hope, he added, have come mostly despite L.A. Unified, not because of it.
"We can see some light," Cubias said. "But between us and that light is a system that makes everything so difficult."
Locke's crew of young math teachers did not land at the school through the district's recruiting and placement office, Cubias said, but because of an informal pipeline he forged with UCLA's education program.
He and other teachers have taken it upon themselves to keep close tabs on new recruits -- stopping by their classrooms between periods or offering advice over a meal after work.
And, when it came to funding the computer lab, the faculty didn't even bother to ask district administrators but secured money themselves directly from the state.
Moreover, in the decade since he earned his teaching credential and returned to Locke, Cubias recalls five principals arriving to run the school. More than a dozen assistant principals have come and gone as well, he said, typically using Locke as a stopover on the way to better positions elsewhere in the sprawling 708,000-student district.
"We get people coming here more to put in their time than to serve the kids," he said. "They are not the type who want to rock the boat when they're here."
The revolving door for administrators, Cubias and several other teachers on both sides of the Green Dot divide said, has left teachers with the sense that the school is adrift, missing the consistent leadership that is often a key element of more successful schools. Without it, small frustrations like the field trip mishap are frequent, and larger reform efforts, including a sweeping plan to divide the campus into several semiautonomous learning communities, have faltered.
And it's the kids, Cubias said, who have paid the price. For every student who graduates from Locke, there is still one who drops out. For years, the school has languished at the bottom of the state's ranking system, and it fares only slightly better when compared to schools with similar challenges.
Last year, 72% of Locke's juniors tested either "below basic" or "far below basic" on California's standardized English test, and 89% of students who enrolled in algebra classes scored at those levels.
Whichever side prevails in the battle for Locke, teachers will continue to face the host of challenges that students bring to school.
