International Air Transport Association (IATA)
IATA is the trade association for the world's airlines and based in Geneva.

International Civil Aviation Organisation (ICAO)
The International Civil Aviation Organisation is a specialised agency of the United Nations that sets international standards for civil aviation. It was established in 1944 by the Convention on International Civil Aviation, also known as the Chicago Convention. It is headquartered in Montreal, Canada, and now has 190 Contracting States. Germany is represented at ICAO by a permanent delegation of the Federal Ministry of Transport and Digital Infrastructure (BMVI).

Instrument flight rules (IFR)
Flights under instrument flight rules take place in controlled airspace where air traffic controllers ensure the safe and efficient handling of air traffic.

Instrument landing systems (ILS)
The instrument landing system (ILS) assists aircraft in landing safely – even in poor weather conditions. Signals are shown on the navigation display in the cockpit providing horizontal and vertical guidance. At nearly all major airports, the descent angle of the ILS is three degrees, whereas the rate of descent depends on the speed of the aircraft. A high-precision instrument landing system (ILS) ensures that aircraft can land safely even in poor visibility conditions. The cross-pointer indicator shows pilots during the entire final approach whether they are heading exactly towards the runway (localiser information) and descending at the ideal angle (glideslope information).