HPa
its all to do with the US habit of knocking off the “2” so 29.91 becomes 991 on the RT.... There was an Airprox a while ago in the Shetland Isles between a US crew in a Kimg Air and an ATR. That’s what caused it all, I’m told. The AAIB report refers. Having said that, I went to SNN recently and the atco asked us what units we were using. Mb obv....! Well, we were tempted to say it for a bit of sport but remained professional with HPa. |
Originally Posted by Thrush
(Post 10414563)
Having said that, I went to SNN recently and the atco asked us what units we were using. Mb obv....! Well, we were tempted to say it for a bit of sport but remained professional with HPa. The result of a number of level busts including a couple where terrain was a factor, from 99X being misunderstood as 29.9X |
There was a suggestion a couple of years ago that an abbreviation of 'hectopascals' might be looked into and agreed, but I've heard nothing since.
|
Originally Posted by chevvron
(Post 10416184)
There was a suggestion a couple of years ago that an abbreviation of 'hectopascals' might be looked into and agreed, but I've heard nothing since.
Oh? What? Were they? Well why the digamma did they change it then? That is not progress. |
Millibars? Nah, not enough syllables :E.
|
DB6,
We're lucky........It could have been Gay-Lussac who did the pressure experiments......Or even worse, Avogadro. :uhoh: |
Imagine if there had been more recent research into pressure by Prof. Brian Cox.
'Hectocox'? Or 'Hectocoxes'. |
Originally Posted by meleagertoo
(Post 10416624)
There is always millibars, a universally-used unit that we all understand and can relate to, unlike the bizarre, meaningless Eurobabble hector-pastilles.
Oh? What? Were they? Well why the digamma did they change it then? That is not progress. |
Nobody knows why ICAO decided on hPa instead of mb especially as the value is the same. |
Thank heavens we're still using feet for all things vertical. Long may it continue to be so.
|
Since (on an appropriate scale) metric aircraft use milimetres to measure length, mililitres to measure volume, miliamps to measure current, milivolts in the electronics, miliTeslas in magnetic fields, and above all pressure in bars it seems a completely retrograde step to suddenly divert from this logical and self-evident progression to abandon milibars in favour of the (to most) largely meaningless hectopascal, be it an SI unit or not.
To me, progress that ain't. |
All times are GMT. The time now is 13:46. |
Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.