Maybe flying is a little too extreme to start off a lucid, especially when you can't handle the excitement. You should probably remain using the usual palm check, nose plug, etc.

As for the reality check in general, I'd say it's just another reality check I guess. Reality checks can range from normal ones to extreme ones (like flying). Anything that can't happen in the real world, but can in a dream, is pretty much a reality check. For example, in the waking world, you would not be able to breathe through a blocked nose, but in a dream you can. For the flying, you can't do it in real life, but in a dream you can .

Hope I explained it okay. Hope to see you around!