Mont Blanc is 15,781ft amsl...so if you want a singe TA across Europe 18,000' makes sense....it is probably just a happy coincidence that it matches the US...
What is really needed is unification of airspace but that is probably the hottest of the hot potatoes in Europe, due to national sovereignty issues.
It is more or less unified. As long as you are not departing continental Europe towards some isolated island Kingdom in the nortwest ;-)
It is more or less unified. As long as you are not departing continental Europe towards some isolated island Kingdom in the nortwest ;-)
Thats funny. The thing is as a Brit, we (or at least I) generally dont want total and complete euro harmonisation, except when it selfishly suits us as individuals. On the one hand we dont want to fill out GAR forms and pass through customs just to relax and eat a croissant in Calais, but on the other hand we are worried about europe controlling out borders and handing more powers over to Europe. It's a brave man (or woman) who tries to harmonise all of these rules. Its impossible to make even half of the population happy I reckon.
How does your transition altitude work? Here in the US, flight levels start at FL180, except when the barometric pressure is below 29.92. Then the lowest usable FL is adjusted upwards as shown below:
(b) The lowest usable flight level is determined by the atmospheric pressure in the area of operation as shown in the following table:
29.92 (or higher) -----------------180
29.91 through 29.42 -------------185
29.41 through 28.92 -------------190
28.91 through 28.42 -------------195
28.41 through 27.92 -------------200
27.91 through 27.42 -------------205
27.41 through 26.92 -------------210
(c) To convert minimum altitude prescribed under Secs. 91.119 and 91.177 to the minimum flight level, the pilot shall take the flight level equivalent of the minimum altitude in feet and add the appropriate number of feet specified below, according to the current reported altimeter setting:
29.92 (or higher) -----------------None
29.91 through 29.42 -------------500
29.41 through 28.92 -------------1,000
28.91 through 28.42 -------------1,500
28.41 through 27.92 -------------2,000
27.91 through 27.42 -------------2,500
27.41 through 26.92 -------------3,000
So nobody has come up with a good reason why FL should start high as opposed to say around 5000ft. The only reason is "it's like that in the US".
Why no, there was a reason "around 18000 skies are very quiet, the lesser pilot load is a good opportunity to change from altitude to FL or v.v." Myself not concerned, I found this the only relevant point ; besides the following of geographical minima aka cumulus granitus.
So nobody has come up with a good reason why FL should start high as opposed to say around 5000ft. The only reason is "it's like that in the US".
This paper is similar to the one posted by Peter initially, only that it's not "UK only" but harmonised Europe-wide. At the very end they ranked their three options (as opposed to the two options of the British proposal) and found, that option 3 is the best one: Leave the decision with every country, but establish a minimum transition altitude of 10,000ft everywhere. Sounds like a good compromise to me.
I'll have to take a look at how TA is noted on charts - no chart I've ever used has made reference to it.
From my point of view, if you were to fly horizontally into flight levels (due lowered TA on your track) it would be awfully confusing. It seems like a whole lot of work to me.
I'll have to take a look at how TA is noted on charts - no chart I've ever used has made reference to it.
It is stated in the header of every Jeppesen SID chart (at least in parts of the world where it is not fixed at 18,000ft). Alternatively in the AIP or the introductory part of the Jeppesen binders.
From my point of view, if you were to fly horizontally into flight levels (due lowered TA) it would be awfully confusing.
Absolutely not different than flying horizontally into an area with another QNH.
I've never used anything from Jeppesen, only VFR charts. I don't even properly know what a SID chart is. Except in airport Class D airspace, I'm rarely in communication with the ground.
Altimeter setting (what you call QNH) changes only slowly with time and movement, due to nature, not arbitrarily in man-made steps.