Altimeter setting units

Kestrel452

Kestrel452

Well-Known Member
What are altimeter settings given in? I thought it was inches of mercury or milibars. Anyone know for sure?

Thanks!
 
yep





(Altimeter settings are in units of pressure: usually either inches of Mercury (inHg), or in millibars (mbar) or hectopascals (hPa). The value corresponds to what the equivalent static pressure at sea level would be if an ISA pressure lapse rate is used to get to the height of the measuring instrument ... I think.)
 
MikeD said:
Oh that's right....lol. Been outta school for a while! :D
Click to expand...
For the benefit of the thread...the setting you put in your altimeter in the USA (29.92) is in inches of mercury (inches Hg), but this is non-standard as far as ICAO is concerned. It should be in hectopascals (1013.25 hPa.)

If you want to get really pedantic you might have noticed that the entire idea of hectopascals is deprecated in the metric system, it really should be in kilopascals, but whatever.
 
Which leads directly to that old chestnut:

An American fellow has gone to all this trouble to fly across the pond to the UK in his Baron. His first landing point is in Northern Ireland.

"Tower, Baron N1234A with you"
"N1234A good afternoon, join downwind for runway 28, maintain 1200 feet, QNH 1023"
"Tower, 34A, join downwind runway 28, maintain 1200 feet, and Sir can I have that in inches?"
"Baron 34A, join downwind runway 28, maintain 14400 inches, QNH 1023"


boom! boom!
 
Timmypig said:
An American fellow has gone to all this trouble to fly across the pond to the UK in his Baron. His first landing point is in Northern Ireland.
Click to expand...

Of interest is that many fields in the UK will give you QFE as their standard (and in milibars, of course).

Gotta make sure you look at the right numbers on the approach plate!

Of course, it helps that the TL in the UK is down around 3,000 feet.
 
Hacker15e said:
Of interest is that many fields in the UK will give you QFE as their standard (and in milibars, of course).

Gotta make sure you look at the right numbers on the approach plate!

Of course, it helps that the TL in the UK is down around 3,000 feet.
Click to expand...

Same in Kuwait. TA is 3000, so go QNE climbing through 3k, and TL is 5000, set QFE when descending through.
 
Hacker15e said:
Of interest is that many fields in the UK will give you QFE as their standard (and in milibars, of course).

Gotta make sure you look at the right numbers on the approach plate!

Of course, it helps that the TL in the UK is down around 3,000 feet.
Click to expand...
Go over to Russia where it's all in Meters...that'll really mess with your mind when you shoot the approach with QFE and have to refer to your altitude conversion chart with every altitude change!!:panic:
 
We set a little bit of everything

You roll in China in Meters (apparently Russia too, but the part we clip going over, they stay in feet).

Most outside the US are hPa that I've seen.

And of course, transition levels run the gammit.
 
You must log in or register to reply here.
Back
Top