A quick google search found me the data page of OpenFlights.org. This page has a free (donation request) CSV file with 8000+ airports: LINK.
OpenFlights.org points to OurAirports.com, which provides extensive CSV downloads with data being in the public domain. See their data page.
Regarding contact info for airport management, the FAA provides this info ...
OurAirports.com is, in my experience, the best data set publicly available. You may find ICAO or IATA missing or outdated here or there, but it's rare (in my experience). They have also categorized the airports as Main or Small, etc, which is particularly helpful, although for the USA, you can simply filter the ICAO code by 'starts with' K and that gets you ...
Another source of airport information around the world is the UN Economic Commission for Europe (UNECE) dataset of United Nations Code for Trade and Transport Locations (UN/LOCODE). These cover major transport terminals: air, sea, land, etc.
A link to the data is here:
I also have a tutorial I wrote awhile ...
Focusing more on the spatial data - but other attributes may be available, you can check:
OurAirports - data available as KML, CSV, with an rss feed of comments describing facilities and current operations
World Aeronautical Database - Not sure how accessible the data is
USSTRATCOM Worldwide Airports - GeoRSS feed; I think the source data is the old ...
The FAA does not seem to provide a stream of ADB-S data, but does provide a stream of about airplane location and disposition called Aircraft Situation Display to Industry. Getting access to this stream is not completely straightforward, but you can start with the FAA's page on the program.
The best that I have found so far is https://opensky-network.org/ It even offers antonymous access to data, but why not join? The REST API is at https://opensky-network.org/apidoc/rest.html
https://www.adsbexchange.com/data/# offers free for non-commercial use data. However, it requires you to set up alive feed of your own data, to share it with others....
Although the FAA does not redistribute ADS-B data, FlightAware (the largest aggregator and provider of this data) does offer worldwide ADS-B data feeds in a variety of formats: https://flightaware.com/commercial/data/adsb/
They do have an aircraft database available right on the website (also for download): https://opensky-network.org/aircraft-database
Otherwise, the usual suspects are there for individual research but no API: https://flightradar24.com/data, FlightAware, Radarbox etc.
You can decode ads-b, FM radio, pager traffic, and various other signals (most anything in the 50MHz -2200 MHz range) with a 9 dollar european TV USB antenna if it has the rtl2832U chipset. Google rtlsdr or rtlsdr ads-b.