| Symbol | Meaning |
|---|---|
| 5A | Specified altitude. QNH of the arrival field / ASR should be used |
| 200 | Specified level only. Lower levels available if co-ordinated |
| MSL | Minimum Stack Level |
|
__ 390 |
Not above specified level |
|
260 __ |
Not below specified level |
|
__ 190 |
At specified level |
| Term | Meaning |
|---|---|
| Bandboxing | Combining two or more sectors into one position. |
| External Agreement | Standing agreements with international units. No co-ordination should be needed if traffic is offered at the levels and points specified but it is good practice to confirm that all agreements are valid when first connecting. |
| Internal Agreement | Standing agreements with other UK sectors. No co-ordination is needed if traffic is offered at the levels and points specified. |
| MSL (Minimum Stack Level) | The lowest whole flight level which provides a minimum of 1000ft separation above the applicable transition altitude. MSL in the London TMA is based on the Heathrow QNH. MSL in the Manchester TMA is based on the Manchester QNH. MSL in the Scottish TMA is based on the Glasgow QNH. |
| Intention Code | Intention codes are used so radar controllers can easily identify the destination or UK FIR exit point of a flight without having to bring up the flight plan. They should always be used in the cleared waypoint field of Aurora. |