If you are flying overseas, in a country where the transition level is 060, and you are being vectored around above this transition level (lets say 8,000 feet). When do you change for the local altimeter?, when told the local altimeter by the controller, or when reaching the transition level?.

Does anyone has a link for an ICAO reg. On this?

Thank you,

 

In my experience, it is when you are below the transition, or during your decent when cleared below the transition level. I don't have a reg on hand.

 

http://www.skybrary.aero/index.php/Transition_Altitude/Level

 

You're expected to change it when you reach it. Just as you would in the US.

 

http://www.airlinepilotforums.com/ai...-vs-level.html

 

The transition altitude is always a published fixed number, 4000', 5000'. The transition level is normally assigned by ATC and will usually be 1000 above the TA. FL050, FL060. It will be adjusted if the local QNH is below 1013hp.

On departure you will change to 1013 at the time you are assigned a flight level. The only caution is to do it no sooner than the flaps up call because if the QNH is low and you change to 1013hp you will clean up too low and may get a noise violation. If you wait until passing the TA with a low QNH you risk an altitude bust.

For arrival you will normally get the Transition Level on the ATIS. Although you should know what the Transition Level is the important thing is to listen to what the controller says. If he says descend to "flight level 50" or just says descend to 50 you are cleared to descend to FL50 and your altimeter remains set at 1013hp. If he says you are cleared to five thousand feet on the QNH of 1004 you have been cleared below the transition level and should change your altimeter to 1004hp as soon as you get your clearance. JUST LISTEN TO WHAT THE SAYS. Americans have a problem with this low TA/TL thing and get themselves in trouble. You are most at risk when the QNH is below 1013.2 or as Americans say Altimeter 29.92. If you are cleared to FL60 you must have 1013/29.92 set in the altimeter window. If you are cleared to 6000' (six thousand feet) you must have the current QNH/Altimeter set. In the states we say six thousand or six zero and we are saying the same thing. It is not the same for the rest of the world.

 

On a practical level, at my company, we set standard during climb when passing the transition altitude, when descending we set QNH as soon as we get cleared to an altitude( caution, if you get an intermediate level of, don't forget to reset to standard if it is a level).