Airports, runways and navaid base layer (worldwide)
OurAirports — Public Domain. Aerodrome data is not taken from the DFS AIP:
DFS publishes it but is not the originator; the rights rest with the individual
aerodrome operators.
Instrument flight procedures — United States
FAA Coded Instrument Flight Procedures (CIFP), ARINC 424. US Government work, Public Domain.