Hectopascals

[RTN11]

So, the Hectopascal is upon us.

Does anyone else find this change in pressure units strange and unnecessary? If nothing else, it's a longer word and doesn't flow quite so well over the radio.

[BackPacker]

Not to mention the conversion charts you need to go from HPa to mbar. Another piece of paper to clutter the cockpit.

[Gomrath]

Inches are so much easier.... but hey we never use the term anyway.

[Jan Olieslagers]

QNH one zero two zero

what could be terser? what's the fuss?

[RTN11]

Generally when the pressure is below 1000, the ATC then finish by saying the unit.

In todays case

niner niner seven hectopascals

[GeeWhizz]

I thought in the world of the met office, its always been hPa. The name changed when published for aviation/naval reporting purposes.

Edit: also the reason for ATC stating the unit when the pressure falls less than 1000 (one thousand hPa/mb), is due to the ambiguity between 997 and _9.97In Hg (29.97 inches if the first '2' is clipped or missed).

[RTN11]

I guess Jan is used to flying round with high pressure.

[M-ONGO]

Must be that famous Belgian high!

I guess Jan is used to flying round with high pressure.

:rolleyes:

[BackPacker]

Inches are so much easier....

Obligatory joke:

United 643 descend to altitude 4,000 feet QNH 1029
Ah, could we get that in inches please United 643
Certainly, United 643 descend to altitude 48,000 inches, QNH Is still 1029

[GeeWhizz]

Oh those Americans definitely like it in inches ;)

[Dan Dare]

Just waiting for them to bring in milliatmospheres - that would roll off the tongue nicely AND be a boost to the economy with all the new altimeters required. Or Torr (mmHg) would be a good compromise - the mercury would keep them happy on one side of the atlantic and mm keeps them happy on the other side and in the rest of the world.

Sad to see the old mb go.

[pitofrost]

Cranfield tower seemed to take great delight in saying hectopascals at every opportunity today. With just a tiny pause to make you wonder if they were going to say it this time "QFE niner niner eight...........hectopascals".

[XLC]

Here in northern Thailand they give the initial reading in hPa, but when asked they give you the reading in Hg as well as they have both data on their screens.

[high wing harry]

"Another piece of paper to clutter the cockpit"

erm... hoping you're joking!!

[ShyTorque]

I'm sure he's joking. Everyone knows that a paper conversion chart wouldn't be nearly accurate enough for something like this.

[BackPacker]

True. You're better off doing the conversion on an E6B, although I think IO540 will be along shortly explaining that using a GPS is better...:ok:

[Dusty_B]

What amuses me most is that just as we are wrapping our tongues around a new, SI/PC phrase, the Russians are busy changing from metric to imperial units for altitude.

[john_tullamarine]

... some of us Luddites are still fighting a (losing) rearguard action for poundals and slugs ... perhaps I should champion the cheval ?

[Lasiorhinus]

Let me get this straight - the UK has changed from measuring air pressure in milliBars, to measuring in Hectopascals... which are identical... and you people are complaining about it?

This is an absolute complete non-issue!

[Heston]

Let me get this straight - the UK has changed from measuring air pressure in milliBars, to measuring in Hectopascals... which are identical... and you people are complaining about it?



Coo! Meta-irony, I'm not sure I can cope. I need a lie down ;)

H

[24Carrot]

This is an absolute complete non-issue!

So on past form, this could become the longest running thread on pprune!

[LeeP-PA28]

LOL @24Carrot.

I don't see the problem myself? Just deal with it!

[dont overfil]

It's a pain when you have to say it 200 times a day. It doesn't exactly roll off the tongue.
D.O.

[Jan Olieslagers]

Well I must admit I had completely missed the point. But now that the matter is on the table: are hectopascals really identical to millibars? I have a suspicion there is some subtle difference, with no practical effect whatever, just like UTC vs. GMT.

@rusty_b: it is quite disappointing to me that the Russians should be giving up on the much more logical metrical units. Do you have any sources? Perhaps they realise metrics were always favoured by bad regimes like Hitler's and Stalin's?

@RTN11: yes I do often fly with high pressure, especially between the upper upper thighs...

[mad_jock]

Mind you have heard already "hecto's"

[Jan Olieslagers]

No I haven't. Not when flying, at least.

[mad_jock]

Bar is a sgc unit invented by a Brit and is nearly 1 atmosphere.

It isn't per say a SI unit. But hectopascal is. There is no difference what so ever about the size of them 1 bar is defined as 100 kilopascals or 1000 hectopascals.

The russians have gone ft in Area but not in Terminal I think it has changed in the last few months.

[vulcanised]

Presumably it's just something else inflicted on us by the EU?

Mind you, ATCOs seem to love verbiage - who else would tell you Outside air temperature plus two zero?

[mad_jock]

Its proberly part of the cunning plan to get the 0 longitude moved to Paris.

[Human Factor]

It's to keep the French happy. Time check 1700 UTC. :rolleyes: