FormerlyHemlock
Hero
Let's say you do beat the dragon in one combat of five using an alternative to fly, but your party dies the other four times. Then let's say you cast fly and win the battle five of five times. Would you consider that fun solving the problem within the parameters of the rules? If the rules create a situation where there is only one highly effective way to solve the problem and all the other methods have a relatively high chance of failure, is that fun to a problem solver like yourself?
I don't think I ever answered this question, so I will now: I think this situation would be significantly more fun if the rules give you zero ways to solve the problem effectively, i.e. if the Fly spell is not available. If I know Fly is going to work for sure then it's unrealistic from an RPG standpoint for the PCs to look for an alternate route instead of just doing what works well and killing it in the air. If there is no easy option then the PCs get creative: going on a hunt for Purple Worms to milk venom to put on your arrows a la Heracles and hydra venom; using illusions to bait a dragon into a 10' tunnel; feeding ingestive poison to a cow which you then contrive to feed to the dragon (the dragon might be less suspicious if you feed the poison to a PC instead

If it works it will be epic. If not, well, you didn't have a better plan anyway! Dying is nothing to be ashamed of.