Suggestion: split type into type and status in airports.csv

[icyrockcom]

Right now, there are entries such as this in airports.csv:

"id","ident","type","name","latitude_deg","longitude_deg","elevation_ft","continent","iso_country","iso_region","municipality","scheduled_service","gps_code","iata_code","local_code","home_link","wikipedia_link","keywords"
...
6526,"00AR","closed","Newport Hospital & Clinic Heliport",35.6087,-91.254898,237,"NA","US","US-AR","Newport","no",,,,,,"00AR"

The problem is that closed makes us lose information regarding what type it was before it got closed. In this particular case, the name field makes it possible to figure out it was a heliport.

In other cases, such as this:

"id","ident","type","name","latitude_deg","longitude_deg","elevation_ft","continent","iso_country","iso_region","municipality","scheduled_service","gps_code","iata_code","local_code","home_link","wikipedia_link","keywords"
...
6529,"00CO","closed","Cass Field",40.622202,-104.344002,4830,"NA","US","US-CO","Briggsdale","no",,,,,,"00CO"

there's not enough information.

I'd suggest splitting this up into type (heliport, small_airport, etc.) and status (open, closed) in order to avoid losing this info and make the database more useful in the future, especially for automated processing.