| Significance | Code | Meaning |
|---|
| FIR | EGTT | London FIR | | | / | | | Qualifiers | Q | | | | CA | Air/ground | | | AS | unserviceable | | | / | | | Traffic | I | IFR traffic affected | | | V | VFR traffic affected | | | / | | | Purpose | 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 | 5133N | 51° 33' North' | | Centre Longitude | 00025W | 0° 25' West | | Radius of area affected | 005 | 5 nautical miles |
| | AIR TRAFFIC CONTROL GROUND RADIO FREQUENCY 121.575 UNSERVICEABLE.ALL AIRCRAFT TO USE TOWER FREQUENCY FOR BOTH TOWER AND GND COMMS DURING THIS PERIOD.AIRCRAFT ON START TO CONTACT AIR TRAFFIC CONTROL WITH CALLSIGN ONLY AND AWAIT AIR TRAFFIC CONTROL RESPONSE TO MINIMISE FREQUENCY CONGESTION FOR AIRCRAFT IN CRITICAL FLT PHASES |
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