Quote History Quoted:
Straight out of Foreflight info:
"ForeFlight Mobile requires about 15.5GB for all of the U.S. airport diagrams, A/FD sheets, instrument procedures, documents, VFR sectionals, and IFR enroute charts".
I usually only download the portions that I regularly fly. If I go out of that area I download the extra before I launch.
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The problem would come when updating. Foreflight downloads the updates before the old charts are kicked out and will, for a couple days, require twice the storage space.
OP, you should be fine if you're only downloading 1 or 2 states worth of charts. With no cellular chip, you won't have a GPS chip either (they're on the same board). You won't have in flight location but that isn't a huge deal but would be great for situational awareness.
I prefer the Mini size of iPad because it fits perfectly in smaller aircraft. I have a RAM mount with the suction cup and if placed correctly, can almost blend in to an empty spot on the instrument panel. If you're planning on flying commercially, practically every single airline provides iPads for their crew or it's assigned to the aircraft so don't upgrade just for this. I always recommend buying the largest size that you can afford but since you already have one and if you only plan on doing local VFR, stick with what you have and save yourself some money.