It seems like your database covers the basics! However, timezone data and airport type/size were pretty important information for us, so we ended up getting these from:
- OpenFlights [1]: this dataset was great since it had timezone too, which was really helpful for calculating flight lengths, etc.
- OurAirports [2]: no timezone here, but the "type" and "scheduled_service" columns in this dataset are essential. "Type" lets you distinguish between small/medium/large airports, and "scheduled_service" lets you easily filter out airports without real flights (which you often might not care about).
- IATA tzmap [3]: this was used for filling in timezone data and is derived from the Geonames database.
- Random other GitHub Gist [4]: I have no idea where this data comes from, but it was surprisingly complete and has a few golden nuggets like "num_flights" and "runway_length" in addition to "timezone". The presence of a "woeid" suggests Yahoo-related origins, but it's hard to be sure.
Long story short, it'd be AWESOME to have one complete, updated database with all this data in one place, but part of the struggle is definitely having more data than just longitude/latitude.
[1] https://github.com/jpatokal/openflights/
[2] http://ourairports.com/data/
[3] https://raw.githubusercontent.com/hroptatyr/dateutils/tzmaps...; http://download.geonames.org/export/dump/