I mostly ignored the zeppelin's health, once I figured out the strategy for that section. There are several gaps in the Black Ring forces, so I would pause each time I finished a section and check the zeppelin; if its HP were down, I missed a tower / ballista / nest, and probably needed to reload and redo that section (being more careful), otherwise I could save and forge ahead. After starting to fly out ahead of the zeppelin, I think I only had to reload twice for missing something that could do a significant amount of damage.