Russian Flight Levels

[Iron City]

Column in Aviation Daily June 3 says ICAO is concerned because Russia uses a different systems than anywhere else for flight levels and this could be a problem as RVSM is introduced. Example given is Rostov FIR that aircraft cross Ukranian airspace at "normal" levels then go into Rostov FIR and change to "Russian" flight levels then go back to "regular" flight levels when the enter the Caucasian states.

As I recall the Russians use a metric altimeter and charting convention, which I believe is entirely in accordance with ICAO rules.

So other than understanding this a bit better the question is is this a manufactured tempest in a teacup or a real problem or something in between?

[Fallows]

I believe that in Russia they use kilometers per hour as a measurement of speed and meters as a measurement of altitude. The conversion was a factor in the mid-air collision between the Saudia Boeing 747 and the Ukrainian freighter on the approach to Delhi a few years ago.

[bekolblockage]

Same in Mainland China.

Odd that ICAO is concerned with the use of meters. Seem to recall the ICAO definition of RVSM being "The vertical separation minimum of 300m (1000ft) between FL290 and FL410 inclusive."

[Squawk7777]

In Russia and China the wind is measured in metres per second.

I agree with bekolblockage. What has the unit (metres or feet) to do with the actual seperation?

[Iron City]

That's what I couldn't figure out also...a distance is a distance whether you measure it in feet or meters or cubits or dynes per cubic parsec.

I think the problem may be in accumulated rounding errors and just the pain in the neck of having to use a different system of measurement.

Although ICAO may say it is so, 300M doesn't equal 1000 feet. a foot is 3.048 decimeters (1/10 of a meter) so if 1 foot is 3.048 decimeters 10 feet is 30.48, 1000 feet is 3,048 decimeters or 304.8 meters. so there is a rounding error of 4.8 meters or 48 decimeters or 48 x .328 ft = 15.744 feet every 1000 feet. If the logic in your computer (be it on the ground or in your aircraft) lets the errors accumulate by the time you get to 30000 feet it is 472 feet, which would eat up the bulk of your half of a 1000 foot reduced vertical separation minima.

[bekolblockage]

To be honest it is a bit of a pain in the neck integrating the 2 Flight Level systems when close to or crossing the boundary. The problem lies in the fact that the standard metric levels don't exactly line up with the imperial ones-e.g. 11,400 m = F374 so that ******s up 370 and 380 on your side if you want to use RVSM.
Just seemed odd to me the way ICAO preferred to refer to the primary level in metric while inserting the imperial equivalent in brackets in their official definition.

[galaxy flyer]

To this westerner, using metric altitudes/levels is silly. The reason separation is 1000 feet is that it is simple to read on altimeters preventing errors by pilots and controllers. I don't have any problem with metrics, but in this case, it just doesn't work unless one trip around the altimeter was to be 300 meters and RVSM everywhere.

GF

[jungly]

Add to that that seperation in Russia is 15km....and that metric FLs are different in China than in Russia & Mongolia.

[Iron City]

Well, Galaxy Flyer, it would be a pain in the neck if I were flying my IL-86 to have to fly at xy,000 feet when my altimeter is in meters. Key to the problem seems to be non-standardness.


Who's (whom's? is that a word) bright idea was it to mix metric in with english (feet/nautical miles)? Are Piper ASI's still in statute miles not nautical miles like Cessna and Beech? Guess it is "nonstandard"

[galaxy flyer]

Well, you got me there, Iron City. I suppose if the Russians used furlongs per fortnight, lack of standardization would still be the problem.

HOWEVER, like it or not, only the former Communist bloc used metric altimetry, so feet is the standard and becoming more so as some Eastern bloc countries convert. No matter, what the ICAO says. Come to think of it, it is a minor wonder Airbus didn't try to force metric altimetry. A French chauvinism effort, but I digress.