| Significance | Code | Meaning |
|---|
| FIR | EGTT | London FIR | | | / | | | Qualifiers | Q | | | | CA | Air/ground | | | CF | operating frequency(ies) changed | | | / | | | 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 | | | E | En-Route information | | | / | | | From flight level | 000 | Surface | | | / | | | Up to flight level | 024 | 2400 feet QNE | | | / | | | Centre Latitude | 5148N | 51° 48' North' | | Centre Longitude | 00044W | 0° 44' West | | Radius of area affected | 002 | 2 nautical miles |
| | HALTON AIR TRAFFIC ZONE AND HALTON GLIDER SITE-AMEND HALTON RADIO FREQUENCY 130.425MHZ TO READ 130.430.UK AERONAUTICAL INFORMATION PUBLICATION ENR 2.2 AND ENR 5.5 REFERS. |
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