Bonjour,In europe this info is given by ATIS with the QNH, does anybody know how is it done in US.Thanks in advance.Claude

I might be wrong..but I believe in the USA its 18,000 feet for all airports.http://www.avsim.com/posky/images/banners/gary_ban.gif

That's correct. Transition altitude in the USA is 18,000 ft. Transition level is FL180.Jon (KSEA)

Hi Thank you for the answer , I knew the TA was 18000 but I thought the QNH had an impact on the TL.I had a second question if TL is 18000 how can we be sure to have receive ATIS at this altitude as we are about 70 nm from the airport and not sure to be in the ATIS range ( I have read it is about 40 Nm)MerciClaude

No one forces you to recieve the ATIS when you are still above TL. As TL is always FL180 in the US, you can recieve the ATIS when lower.Also, the range of ATIS depends on altitude (as with all VHF radio stations). The higher you are, the greater its range. (up to 200 miles, but that would require a very strong radio station)

In USA the rules are simple: 18000 and above - you must fly IFR and use 29.92 as your barometric setting.Below 18000 - you can fly VFR/IFR and use the setting of the nearest reporting station. (but it doesn't mean you have to occupy your time 100% by searching for the best setting). Common sense should prevail ... Michael J.

The controllers will give you an altimeter setting when they descend you below the transition level.

Merci.Could you confirm if this altimeter setting given by ATC is the same than the one given by ATIS.Best regards.Claude

It could be an altimeter setting for a station in your area, not necessarily for your destination. If your destination is a considerable distance away or the weather in your local area as you pass through transition level is quite different (e.g., passing through a front) you would be given an altimeter setting appropriate to that area. If the difference is marginal, they may give it for your destination. They will frequently tell you if it is for your destination by saying something like, "Altimeter at KJFK, 30.12." The primary reason for giving you the altimeter setting (barometric reading) is for separation from other traffic. If everyone in your area is on the same setting, it makes the skies a bit safer.

Jon,Technically, 18000 is the transition altitude in Canada/US/AK but the transition level is not necessarily always FL180. Transition level is defined as the lowest flight level available for use above the transition altitude and if the altimeter setting is less than 29.92, then FL180 is not available (ATC will not allow you to cruise at that altitude because there would be less than 1000 ft spacing with aircraft at 17000 flying on the local altimeter setting).Therefore to be technically correct, the TL in N. America varies from FL 180 to FL200, depending on the local altimeter setting.Kevin in CYOW