When to change to 1013mb?
Following discussion with a colleague I would like to hear ATC's opinion please.
In the London area the transition is 6,000ft. My old airline’s SOP was to change to 1013mb as soon as we are cleared to a FL. However my current SOP (different airline) is to change to 1013mb at transition altitude and not before.
The uk rules (notified difference from ICAO) say (from memory) that when cleared to a FL all references to height shall be expressed with reference to 1013mb. Thus indicating that the change to 1013mb shall be carried as soon as one is cleared to a FL. But does it actually mean that…or does it just mean if the passing height has to be passed to ATC then it should be given as a FL.
The tricky thing would be to have to stop the climb after having changed to 1013mb. Would ATC instruct me to stop the climb at an altitude or a flight level? (bearing in mind, in this case, I am still below the transition altitude)
Cheers HP