Is there an air traffic controller type who might be able to answer. I am not familiar with the Los Angeles area, but looking at the terminal chart; it seems that the area in which the pilot was flying was Class G to 700' AGL overlain by Class C airspace (thick magenta line) which goes to 4000'. That would imply equipment needed, visibility and cloud separation required, and communication. What would be the intent to climb specifically to 4000' ? (why not 3500' or 4500'?). Standard ops would imply communication with the company to describe a deviation from original dispatched flight and a communication with ATC to outline intended plan upon reaching stated altitude. What woiuld a controller be expecting in such circumstances.