Viscount724
Topic Author
Posts: 19065
Joined: Thu Oct 12, 2006 7:32 pm

Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 6:18 am

I understand that certain countries use meters rather than feet for air traffic control purposes. I believe Russia is one, and if not mistaken China. What others?

How does it work whey an aircraft crosses the boundary between an area where altitudes are in feet and one where metric altitudes are used? Assume the aircraft has to climb or descend slightly to reach an even altitude in meters, and then do the same again when it passes out of the metric area into another region that uses feet?

What terminology is used in ATC communications for altitudes when meters are used, e.g. the equivalent of Flight Levels etc, and are they established in even numbers of meters, equivalent to FL350, 380, 410 etc. for altitudes measured in feet?

Does current glass-cockpit software permit automatic conversion/display of altitudes in both feet and meters, or does it have to be converted manually?

Thanks for any related info.

[Edited 2006-12-14 22:20:04]
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 6:53 am

Pretty sure Sweden uses meters for military aviation.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
avt007
Posts: 1989
Joined: Mon Jul 10, 2000 4:51 am

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 7:09 am

An option on the CRJ is to have a metric/standard altitude switch. Any glass cockpit aircraft should easily be able to switch to one or the other. However I can't think of any other countries that use metric.
 
FredT
Posts: 2166
Joined: Thu Feb 07, 2002 9:51 pm

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 8:00 am

Quoting Starlionblue (Reply 1):
Pretty sure Sweden uses meters for military aviation.

They're switching over. Not sure if the switch has been completed yet, but it is coming.

Soaring is still metric though!

Rgds,
/Fred
I thought I was doing good trying to avoid those airport hotels... and look at me now.
 
Pihero
Posts: 4206
Joined: Mon Jan 31, 2005 5:11 am

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 8:25 am

Quoting Viscount724 (Thread starter):
I understand that certain countries use meters rather than feet for air traffic control purposes. I believe Russia is one, and if not mistaken China. What others?

You rightly quoted Russia and China (PRC) and you should add North Korea and Mongolia.

Quoting Viscount724 (Thread starter):
How does it work whey an aircraft crosses the boundary between an area where altitudes are in feet and one where metric altitudes are used?

Good guess . You have a buffer zone between FIRs where your aircraft would go from a feet-flight level to a meter one (and vice-versa)
For instance, suppose you're on an eastbound Europe to Japan via Siberia and you'll be transferred at IGROD point from Vladivostok ATC to Tokyo.
At that point, you should be cruising at a level of 11,100 meters (that's 36,400 ft)...45 Nm before IGROD, you'll climb to FL 370 in order to be at that level at least 15 Nm before the overhead.
On the westbound flight,you would fly at FL 390 (you have a super airplane !).
In this case, you would maintain your flight level until 15 Nm after the boundary and you'll then descend to a meter level of 11,600 m.

Quoting Viscount724 (Thread starter):
What terminology is used in ATC communications for altitudes when meters are used, e.g. the equivalent of Flight Levels etc, and are they established in even numbers of meters, equivalent to FL350, 380, 410 etc. for altitudes measured in feet?

For these countries,a standard altimeter setting calls for a flight level ("fright reverr " in Japanese) : you just say "xxx,maintainingf flight level 11 thousand 600 meters".
Over Russia, it is not easy to remember odd / even levels : there is a 300 m separation between eastbounds and westbounds until 8100 mat which point the separation becomes 500 m, like this (< is w/b , > is e/b )
13100>
12100<
11600>
11100<
10600>;
;
;
;
9100<
8600>
8100<
7800>
7500<
7200> etc...
The Asian system is even different 300 m separation up to 3900 m and then 600m thereafter.

Quoting Viscount724 (Thread starter):
Does current glass-cockpit software permit automatic conversion/display of altitudes in both feet and meters, or does it have to be converted manually?

Yes, on Boeings, you have a meter-foot selector.
I've heard that the option is possible on Airbuses. Our airline did not choose it as we found out that at low altitudes a mismanagement of the switch would be very dangerous. Therefore, our aircrews carry a conversion table card and we stay with a reading in feet (there is, though, the possibility of a meter reading at the bottom of the lower ECAM, should you so wish ). For example, being cleared to a flight level of 11,400 m, we acknowledge,convert and x-check "37,400 ft".
That altimeter-setting discipline is paramount on these regions, compounded with the fact that there is no QNH, therefore at transition, without the ATCO telling you the setting, you'll have to enter a QFE height...Suppose you're descending to an airport,100m high and you were cleared to 2,100 m - that's a flight level - and the ATCO then clears you to 700m -that's a QFE height - .
Suppose a rather low pressure and you'd run fast out of altitude !
Sorry for the long post, it's not very easy !

Regards
Contrail designer
 
User avatar
Starlionblue
Posts: 17117
Joined: Fri Feb 27, 2004 9:54 pm

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 10:27 am

Quoting FredT (Reply 3):
Quoting Starlionblue (Reply 1):
Pretty sure Sweden uses meters for military aviation.

They're switching over. Not sure if the switch has been completed yet, but it is coming.

Soaring is still metric though!

Yet another NATO harmonization?

Quoting Pihero (Reply 4):
a flight level ("fright reverr " in Japanese)

 rotfl 

Quoting Pihero (Reply 4):
Airbuses.

I beg thee: "Airbi". Big grin
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
Viscount724
Topic Author
Posts: 19065
Joined: Thu Oct 12, 2006 7:32 pm

RE: Countries Using Metric Altitudes For ATC

Fri Dec 15, 2006 11:25 pm

Pihero, thanks very much for the excellent information. Just what I was looking for.

Who is online

Users browsing this forum: Horstroad and 16 guests