| Significance | Code | Meaning |
|---|
| FIR | EGTT | London FIR | | | / | | | Qualifiers | Q | | | | IL | Localizer (ILS) | | | AS | unserviceable | | | / | | | Traffic | I | IFR traffic affected | | | / | | | Purpose | N | For immediate attention of aircraft operators | | | B | For inclusion in Preflight Infomation Bulletins | | | O | Operationally significant for IFR flights | | | / | | | Scope | A | Aerodrome information | | | / | | | From flight level | 000 | Surface | | | / | | | Up to flight level | 999 | Unlimited | | | / | | | Centre Latitude | 5204N | 52° 4' North' | | Centre Longitude | 00037W | 0° 37' West | | Radius of area affected | 005 | 5 nautical miles |
| | RUNWAY 21 LOCALISER UNSERVICEABLE.LOCALISER 21 INSTR APP UNAVBL. |
|
