Air Traffic Services — ATC / FIS / AAS
General (ICAO)
ICAO Annex 11 defines three main services:
| Service | Task |
|---|---|
| ATC (Air Traffic Control) | Active traffic control with clearances |
| FIS (Flight Information Service) | Information without clearances (weather, traffic info) |
| AAS (Aerodrome Advisory Service) | Recommendations at uncontrolled airfields |
| ALS (Alerting Service) | Alerting SAR in emergencies |
ATC — three sub-services
Air traffic control service is conducted by TWR (Aerodrome Control Service), APP (Approach Control Service) and ACC (Area Control Service):
| Service | Name | Task |
|---|---|---|
| TWR (Tower) | Aerodrome Control Service | Aircraft in tower area, runways, pattern |
| APP (Approach) | Approach Control Service | Arrivals/departures, TMA |
| ACC (Area Control) | Area Control Service | En-route, FIR |
FIS
A pilot can contact FIS (Flight Information Service) via radio communication:
- Provides information on weather, airspaces, other traffic.
- FIS is available to a pilot during the flight in a FIR (Flight Information Region).
- No ATC clearances, only information and advice.
TRA — Temporary Reserved Airspace
"TRA" is a "Temporary Reserved Airspace":
- Temporarily reserved airspace (military exercise, etc.).
- May be crossed when inactive.
Restricted areas — crossable with restrictions
A restricted area can be crossed with certain restrictions applying:
- Permission from the responsible ATC unit required.
- Restrictions depend on activity.
Radio failure at uncontrolled field
During an approach to an uncontrolled airfield with an occurring radio failure, the pilot should join the traffic pattern, watch out for landing and departing traffic and land while maintaining visual flight rules.
Europe (EASA / EU)
SERA Section 9 Information services governs FIS, AAS.
Germany (national)
In Germany there are three FIRs in the lower airspace: In Germany, Bremen, Langen and Munich exist as flight information regions in lower airspace.
Squawk 7600 on radio failure
Transponder code 7600 should be set without any request in case of radio failure:
- Pilot sets it independently (no ATC instruction).
- ATC sees "RCF" on the radar display.