General (ICAO)
The Aerodrome Reference Code per ICAO Annex 14 Vol I, §1.6 classifies an aerodrome by the characteristics of the aircraft expected to use it. It consists of a Code Number (Element 1) and a Code Letter (Element 2).
Code Number (Element 1) — based on Aerodrome Reference Field Length (ARFL) of the most demanding aircraft:
| Code Number | ARFL |
|---|---|
| 1 | < 800 m |
| 2 | 800 m to < 1 200 m |
| 3 | 1 200 m to < 1 800 m |
| 4 | ≥ 1 800 m |
ARFL = the shortest take-off run at MTOM, ISA (15 °C), MSL, zero wind, zero slope.
Code Letter (Element 2) — based on wingspan OR Outer Main Gear Wheel Span (OMGWS):
| Code | Wingspan | OMGWS |
|---|---|---|
| A | < 15 m | < 4.5 m |
| B | 15 m to < 24 m | 4.5 m to < 6 m |
| C | 24 m to < 36 m | 6 m to < 9 m |
| D | 36 m to < 52 m | 9 m to < 14 m |
| E | 52 m to < 65 m | 9 m to < 14 m |
| F | 65 m to < 80 m | 14 m to < 16 m |
The Code Letter is the higher of the two values (wingspan or OMGWS).
Examples:
- Cessna 172 (wingspan ~11 m, ARFL ~400 m) → 1A.
- Airbus A320 (wingspan ~36 m, ARFL ~2 100 m) → 4C.
- Boeing 747 (wingspan ~64 m, ARFL ~3 000 m) → 4E.
- Airbus A380 (wingspan ~80 m, ARFL ~3 000 m) → 4F.
Use: The code determines minimum dimensions for runways, taxiways, safety strips, lighting etc. (Annex 14 §3 and §5).
Europe (EASA / EU)
Applied via Regulation (EU) 139/2014 (Part-ADR) and CS-ADR-DSN Book 1, Subpart B (Aerodrome Reference Code). Identical with ICAO Annex 14.
Germany (national)
EU law. AIP Germany AD section publishes the Reference Code Number/Letter per commercial airport and controlled special-purpose aerodrome (e.g. Frankfurt 4E, Munich 4F, small VFR aerodromes typically 1A or 2B).