Why is the TA set at 18000 ft in the USA?
Thread Starter
Joined: Jan 2007
Posts: 194
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From: here where I live
Why is the TA set at 18000 ft in the USA?
Hi guys,
I often play with a Captain a quiz game with aeronautical questions. He ask me something and I have to find an answer, there is no time limit for that and we may use all the means available to get it (my Iphone was really useful during a transit
); and vice versa. Now, it's my turn to answer him, and the heading of this thread is the question:
Why is the TA set at 18000 ft in the USA?
(the only tip he gave me is that it's a technical reason)
Thank you mates
PS: I've never flown in the USA, he was an instructor in a flying club there..
I often play with a Captain a quiz game with aeronautical questions. He ask me something and I have to find an answer, there is no time limit for that and we may use all the means available to get it (my Iphone was really useful during a transit
); and vice versa. Now, it's my turn to answer him, and the heading of this thread is the question:Why is the TA set at 18000 ft in the USA?
(the only tip he gave me is that it's a technical reason)
Thank you mates
PS: I've never flown in the USA, he was an instructor in a flying club there..
Joined: Jul 2001
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From: Gold Coast
I believe it's due to the height of the mountains in the country.
For example, Holland is about as flat as an ironing board and the transition level is down around FL050 from memory.
In Papua new Guinea is about FL200 I think due to the large mountains. In Australia it's FL110 because we only have medium-sized rocks here.
For example, Holland is about as flat as an ironing board and the transition level is down around FL050 from memory.
In Papua new Guinea is about FL200 I think due to the large mountains. In Australia it's FL110 because we only have medium-sized rocks here.
Joined: Apr 2009
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From: MOER
Thread Starter
Joined: Jan 2007
Posts: 194
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From: here where I live
Ok but, in this case, it's not just a "USA related" question.
That link shows different advantages of using a fixed TA in all over the world.
Maybe the Captain's question was not intended to be a USA only condition.
That link shows different advantages of using a fixed TA in all over the world.
Maybe the Captain's question was not intended to be a USA only condition.
Joined: Jan 2007
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From: California
Instesting article about a common TA in Europe
http://www.eurocontrol.int/airspace/...erspective.pdf
http://www.eurocontrol.int/airspace/...erspective.pdf
Joined: Feb 2008
Posts: 352
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From: on a beach
JetMcQuack, it's not transition altitude, it is transition level because in the
U.S. it is FL180. The TA is 17.000 ft.
I guess it is because the americans are very practical and would rather change the atlimeter setting always at the same place and when you are less busy than down low and close to the ground.
U.S. it is FL180. The TA is 17.000 ft.
I guess it is because the americans are very practical and would rather change the atlimeter setting always at the same place and when you are less busy than down low and close to the ground.
Joined: Nov 1999
Posts: 647
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From: East side of OZ
it's not transition altitude, it is transition level because in the
U.S. it is FL180. The TA is 17.000 ft
U.S. it is FL180. The TA is 17.000 ft
On all the USA Jepp charts I've ever seen it states that
Trans level: FL180 Trans alt: 18000'
The USA and Canada adopted the 18000/FL180 transition as it is generally higher than most of the mountainous areas of each country. The notable exceptions being Mt McKinley in Alaska and Mt Logan in the Yukon.
Regards,
BH.
Joined: Apr 2007
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From: Here, there, everywhere
Try the US AIP, or their equivalent.
From memory, they wanted a TA that would work right across the country and 18,000 was lowest altitude that would work. I could be very wrong though...
Some explanations in the AIP, ENR 1.7; http://www.faa.gov/air_traffic/publi...bs/AIP/aip.pdf
From memory, they wanted a TA that would work right across the country and 18,000 was lowest altitude that would work. I could be very wrong though...
Some explanations in the AIP, ENR 1.7; http://www.faa.gov/air_traffic/publi...bs/AIP/aip.pdf
Last edited by Love_joy; 21st February 2010 at 21:23.
Joined: Dec 2003
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From: Sussex
Some good stuff here
http://www.caa.no/multimedia/archive..._for_6358a.pdf
See also:
Comment: Europe should have a common, higher transition altitude
The CAA might get it one day
See also:
Comment: Europe should have a common, higher transition altitude
The CAA might get it one day
PPRuNe Bashaholic
Moderator
Joined: Jun 1997
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From: The Peoples Alcoholic Republic of Jockistan
If they can sort out the issues of which QNHs to use where, and how pilots obtain them, I see no reason why we shouldn't raise it up to 10,000' or higher in Europe.
Doesn't seem to be a mad rush though. The discussions have been kicking around for over 15 years in the UK CAA alone.
Doesn't seem to be a mad rush though. The discussions have been kicking around for over 15 years in the UK CAA alone.
Joined: Mar 2000
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From: Arizona USA
Those with long memories will recall that the USA at one time had three levels of airways, low...to 14,000 feet, intermediate 14,000 to 24,000 feet, and jet airways, FL240 and above.
When the change was made for jet airways to be lowered to 18,000 feet, and at the same time (or slightly later) the positive control area (class A airspace) was to be lowered to FL180, both east and west transistion levels were set at...18,000 ft/FL180.
When the change was made for jet airways to be lowered to 18,000 feet, and at the same time (or slightly later) the positive control area (class A airspace) was to be lowered to FL180, both east and west transistion levels were set at...18,000 ft/FL180.