Altitude reporting - Meters or Feet
Thread Starter
Joined: Jul 2002
Posts: 103
Likes: 0
From: Lost in thought
Altitude reporting - Meters or Feet
Trying to get a sanity check on this.... My understanding is that most of the world has altimeters that report in feet ASL..... baro correction may be in either milibars or inches - but the altitude itself is in feet. You report too ATC in feet. ATC clears you to altitude in feet. To my knowledge it is only the ex-soviet block countries that work in meters ASL.... True or False?
Moderator
Joined: Feb 2000
Aviation Qualifications: CPL
Posts: 14,480
Likes: 178
From: UK
"US xxx descend 4000 ft on QNH 1025"
"London information, could I have that in inches?"
"US xxx, apologies, descend four eight thousand inches, on QNH 1025".
There are some countries where different traffic uses different units. For example in France commercial air traffic uses feet, but some domestic GA uses metres, and I believe (2nd hand information) that in Sweden civil traffic uses feet and knots, whilst military uses metres and kph. In Romania I've been given surface wind in metres/second and had to do some rapid mental arithmetic to work it out in knots.
We do need standardisation - personally I'd go for feet, knots and millibars and bin the rest. But if we all went for metres, metres/second and hPa at-least we'd be speaking the same language. It's the plethora that is dangerous.
Or perhaps a worldwide alternate standard. You either use m, m/s, hPa, litres OR ft, kn and "Hg, gal. All pilots learn both, and we might be able to cope.
Oh yes, and at-least get rid of those strange aberrations - US gallons, kph, statute miles and mph - they don't help. Okay, maybe in aviation imperial gallons are the aberration, but just one PLEASE.
But I do really, really, hate getting into a strange foreign aeroplane and trying to fly a visual circuit with an altimeter in metres
G
"London information, could I have that in inches?"
"US xxx, apologies, descend four eight thousand inches, on QNH 1025".
There are some countries where different traffic uses different units. For example in France commercial air traffic uses feet, but some domestic GA uses metres, and I believe (2nd hand information) that in Sweden civil traffic uses feet and knots, whilst military uses metres and kph. In Romania I've been given surface wind in metres/second and had to do some rapid mental arithmetic to work it out in knots.
We do need standardisation - personally I'd go for feet, knots and millibars and bin the rest. But if we all went for metres, metres/second and hPa at-least we'd be speaking the same language. It's the plethora that is dangerous.
Or perhaps a worldwide alternate standard. You either use m, m/s, hPa, litres OR ft, kn and "Hg, gal. All pilots learn both, and we might be able to cope.
Oh yes, and at-least get rid of those strange aberrations - US gallons, kph, statute miles and mph - they don't help. Okay, maybe in aviation imperial gallons are the aberration, but just one PLEASE.
But I do really, really, hate getting into a strange foreign aeroplane and trying to fly a visual circuit with an altimeter in metres
G
Last edited by Genghis the Engineer; 13th April 2004 at 09:03.
Joined: Feb 2002
Posts: 364
Likes: 0
From: Just over there....no there.
I can't for the life of me understand why the e-block countries use M/S for windspeed, what use is that apart from testing to see if the pilot can do his bloody mental arithmatic!
I could understand Km/h, at least it's a speed that might be on a dial somewhere in the aircraft.
Knots and feet are such an ancient and wonderful thing...aaah bliss.
I could understand Km/h, at least it's a speed that might be on a dial somewhere in the aircraft.
Knots and feet are such an ancient and wonderful thing...aaah bliss.
Thread Starter
Joined: Jul 2002
Posts: 103
Likes: 0
From: Lost in thought
I agree.... Although I love the metric system normally.... for navigation purposes nautical miles is definitely the way to go - which means speeds in knots, wind-speeds in knots, etc....... Kilometers & meters are for surface vehicles (or for ranging weapons to shoot at surface vehicles... either way).
.... that's the horizontal world
But my question was solely about the vertical world.... perhaps I need to clarify.... I'm being told that in certain parts of the world, people add a second altimeter that reads altitude in meters rather than feet so they don't have to translate what they get from ATC. So does that mean there are parts of the world where you can't operate in feet?
.... that's the horizontal world
But my question was solely about the vertical world.... perhaps I need to clarify.... I'm being told that in certain parts of the world, people add a second altimeter that reads altitude in meters rather than feet so they don't have to translate what they get from ATC. So does that mean there are parts of the world where you can't operate in feet?
Joined: Jan 2000
Posts: 1,415
Likes: 90
As previously mentioned - yes, for many, many years in most of the former Soviet Union, Mongolia and China. It is allowable under ICAO - and you can fit another altimeter if you want, or use an FMS that is switchable bewteen the different units. It's not that dramatic (you can cvarry a conversion table), though it has undoubtedly been a factor in more than one accident in the past..
Do remember as well, the good 'ol USA is the most ICAO non-compliant country in the world...., but I guess that's OK as you generally started most of it....
Do remember as well, the good 'ol USA is the most ICAO non-compliant country in the world...., but I guess that's OK as you generally started most of it....
