PPRuNe Forums


ATC Issues A place where pilots may enter the 'lions den' that is Air Traffic Control in complete safety and find out the answers to all those obscure topics which you always wanted to know the answer to but were afraid to ask.

Reply
 
Thread Tools Search this Thread
Old 11th Sep 2017, 23:04   #21 (permalink)
 
Join Date: Dec 2002
Location: Where the Quaboag River flows, USA
Age: 64
Posts: 3,159
Do Yanks still really get confused by QNH settings less than 1000 mb? Really? I only few outside the US for 28 years so maybe a bit shocked.

GF
galaxy flyer is offline   Reply With Quote
Old 11th Sep 2017, 23:41   #22 (permalink)
 
Join Date: Sep 2011
Location: Scotland
Posts: 86
Still keep saying hectopastels for some reason. Don't think they notice though.
NorthernChappie is offline   Reply With Quote
Old 11th Sep 2017, 23:43   #23 (permalink)
 
Join Date: May 2015
Location: Inverness
Posts: 858
'Fruit pastels' and I haven't been queried yet..
TangoAlphad is offline   Reply With Quote
Old 12th Sep 2017, 09:49   #24 (permalink)
DB6
 
Join Date: Apr 1999
Location: Dundee, Scotland
Age: 54
Posts: 1,243
The only reason we have to say hectopascals is because they couldn't think of a word with any more f#@king syllables.
DB6 is offline   Reply With Quote
Old 12th Sep 2017, 16:16   #25 (permalink)
 
Join Date: Nov 2005
Location: River Thames & Surrey
Age: 69
Posts: 6,805
Quote:
Originally Posted by LEGAL TENDER View Post
It was introduced in 2011.
Was awkward for a couple of days and then business as usual.

Shows the adaptability to change of some in this profession
Maybe at your unit but you must be in a minority; I still hear people say 'millibars'.
chevvron is offline   Reply With Quote
Old 12th Sep 2017, 20:39   #26 (permalink)
 
Join Date: Jan 2008
Location: The foot of Mt. Belzoni.
Posts: 1,817
Given the spread of units used in aviation, 'millibars' make sense. I Bar = 1 Atmosphere.

Change for the sake of it, driven by The EU........And an extra syllable to-boot.
ZOOKER is offline   Reply With Quote
Old 12th Sep 2017, 21:32   #27 (permalink)
 
Join Date: May 2000
Location: Living In The Past
Age: 69
Posts: 269
@ Galaxy Flyer
Quote:
Do Yanks still really get confused by QNH settings less than 1000 mb? Really? I only few outside the US for 28 years so maybe a bit shocked.
Certainly when the US military started operating from Prestwick during the Kosovo conflict, we were very careful about readbacks of altimeter settings. Right up until I retired 4 years ago, there was still the very occasional prompt needed with C130 crews. My suspicion is that possibly, being ANG , they were more used to flying domestically in the USA - or maybe it was just habit ?
Eric T Cartman is offline   Reply With Quote
Old 13th Sep 2017, 11:40   #28 (permalink)
 
Join Date: Aug 2000
Posts: 191
Quote:
Originally Posted by Gonzo View Post
Yes, let's ignore the level busts and near-level busts caused by N. American-based crews hearing 992(mb/hpa) and entering 29.92(in) (or similar), let alone the many every U.K. controller has caught at the readback stage.
If you would give links to airporox reports where this has occurred I'd be pleased to reconsider.

The unit added on to the number is immaterial. If a US crew were going to set inches, would it Hectopascal, rather than 'millibar' or 'smarties' really have saved the day?
MaxReheat is offline   Reply With Quote
Old 13th Sep 2017, 12:06   #29 (permalink)
 
Join Date: Nov 2005
Location: River Thames & Surrey
Age: 69
Posts: 6,805
Quote:
Originally Posted by MaxReheat View Post
If you would give links to airporox reports where this has occurred I'd be pleased to reconsider.

The unit added on to the number is immaterial. If a US crew were going to set inches, would it Hectopascal, rather than 'millibar' or 'smarties' really have saved the day?
If the CAA say you gotta do it, then you gotta do it.
I was on the Phraseology Committee where it was discussed and it was a bone of contention for several other members who didn't want to add the word hectopascals in the same way we had been required to add millibars on the grounds no other country did it.

Last edited by chevvron; 14th Sep 2017 at 06:38.
chevvron is offline   Reply With Quote
Old 13th Sep 2017, 14:39   #30 (permalink)

 
Join Date: Dec 1999
Location: LHR/EGLL
Age: 38
Posts: 4,186
Quote:
Originally Posted by MaxReheat View Post
If you would give links to airporox reports where this has occurred I'd be pleased to reconsider.

The unit added on to the number is immaterial. If a US crew were going to set inches, would it Hectopascal, rather than 'millibar' or 'smarties' really have saved the day?
? Who said anything about airprox? You don't think level busts, or potential level busts, are serious in and of themselves?

Yes, adding the unit following the value certainly has saved level busts.
Gonzo is offline   Reply With Quote
Old 13th Sep 2017, 19:03   #31 (permalink)
 
Join Date: Sep 2000
Location: South of England
Posts: 1,029
Quote:
I was on the Phraseology Committee where it was discussed and it was a bone of contention for several other members who didn't want to add the word hectopascals in the same way we had been required to add millibars on the grounds no other country did it.
Perhaps those members of the PWG should be replaced on grounds of inadequate powers of logic and being Bears of Very Little Brain.

2 s
2 sheds is offline   Reply With Quote
Old 13th Sep 2017, 20:54   #32 (permalink)
 
Join Date: Nov 2005
Location: River Thames & Surrey
Age: 69
Posts: 6,805
Quote:
Originally Posted by 2 sheds View Post
Perhaps those members of the PWG should be replaced on grounds of inadequate powers of logic and being Bears of Very Little Brain.

2 s
I'd like to tell you who it was but I can't.
chevvron is offline   Reply With Quote
Old 13th Sep 2017, 21:20   #33 (permalink)

Avoid imitations
 
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 11,065
Chevron, your last post opens up a new discussion topic. Why should we not know the names of the unelected few who rule our industry? As far as I'm aware, all other government departments are open.
ShyTorque is offline   Reply With Quote
Old 14th Sep 2017, 06:41   #34 (permalink)
 
Join Date: Nov 2005
Location: River Thames & Surrey
Age: 69
Posts: 6,805
Quote:
Originally Posted by ShyTorque View Post
Chevron, your last post opens up a new discussion topic. Why should we not know the names of the unelected few who rule our industry? As far as I'm aware, all other government departments are open.
I've already had a slap on the wrist for revealing things about the PWG (in this case the 'change' from Class F to Class E airspace) so I'm not doing it again.
chevvron is offline   Reply With Quote
Old 14th Sep 2017, 07:37   #35 (permalink)
 
Join Date: Oct 1999
Location: Near VTUU or EGPK
Age: 58
Posts: 225
Somebody forgot to ask the VOLMET lady to record hectopascals.
On the Scottish version, they are not added when the QNH drops to 999 or below.
The Fat Controller is offline   Reply With Quote
Old 14th Sep 2017, 07:43   #36 (permalink)

Avoid imitations
 
Join Date: Nov 2000
Location: Wandering the FIR and cyberspace often at highly unsociable times
Posts: 11,065
Quote:
Originally Posted by The Fat Controller View Post
Somebody forgot to ask the VOLMET lady to record hectopascals.
On the Scottish version, they are not added when the QNH drops to 999 or below.
Maybe the pilots entering Scottish airspace from overseas are better trained with regard to altimetry....
ShyTorque is offline   Reply With Quote
Old 14th Sep 2017, 10:44   #37 (permalink)
 
Join Date: May 2005
Location: Milton Keynes
Posts: 635
WE were slow to change - hectopascals in use in Pakistan in the 90s.
22/04 is offline   Reply With Quote
Old 14th Sep 2017, 17:30   #38 (permalink)
 
Join Date: Oct 2001
Location: wherever will have me
Posts: 683
The 'unelected few who rule the industry' come from a variety of aviation related organisations including airlines, civil ANSPs (not just you know who), MOD, GA and the CAA. They receive briefing papers on the subjects to be discussed ahead of the meeting and you'd hope that they might discuss the issues with their peers. That said, they attend the PWG as themselves, not to represent their organisations.

In relation to the topic of conversation, agree that the unit used is immaterial (millibars or hectopascals) but there continues to be a fairly valid reason for its inclusion and it's not just to mitigate against the acts of our colonial cousins. It's something that has been seen in a number of international carriers; albeit infrequently. That said, there have been occurrences where a controller has persevered with obtaining a full readback of the QNH value and the units and the pilot has still set the QNH in inches of mercury

In previous years I'd mention something about Darwin at this point but I've been trying to act more responsibly

The problem that you have is that we don't gather any evidence to demonstrate how often this has proved effective in preventing a level bust. In order for the CAA to remove the requirement to state the units they'd need to produce a solid safety argument that it was no longer required and I don't think that it would be possible to demonstrate an equivalent level of safety given the absence of evidence. Maybe with enhanced Mode S with reliable barometric pressure setting downlinks so that ATS could identify incorrect altimeter settings but the BPS reliability isn't quite there yet.
whowhenwhy is offline   Reply With Quote
Old 15th Sep 2017, 08:14   #39 (permalink)
 
Join Date: Sep 2000
Location: South of England
Posts: 1,029
Alternatively, if there were a move for ICAO to standardise the units worldwide and phase out inches of mercury...

2 s
2 sheds is offline   Reply With Quote
Old 15th Sep 2017, 23:39   #40 (permalink)
 
Join Date: Jun 2008
Location: Luton
Posts: 311
What annoys me is aircraft that have their tyre pressures quoted in MPa when my pressure gauge is marked in Bar and psi! (Multiply by 10 to get bar.)
Jim59 is offline   Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT. The time now is 02:05.


1996-2012 The Professional Pilots Rumour Network

SEO by vBSEO 3.6.1