Home |
Search |
Today's Posts |
![]() |
|
London Transport (uk.transport.london) Discussion of all forms of transport in London. |
Reply |
|
|
LinkBack | Thread Tools | Display Modes |
#11
![]() |
|||
|
|||
![]()
["Followup-To:" header set to uk.transport.london.]
In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Also, it's hundreds of feet, not thousands. Also it's not feet everywhere. -- Mike Bristow |
#12
![]() |
|||
|
|||
![]()
On Fri, 15 Jan 2016 12:29:53 +0000, Mike Bristow
wrote: ["Followup-To:" header set to uk.transport.london.] In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Not for a layman. When pilots announce the altitude in thousands of feet, it's always based on the flight level, not the true GPS altitude. The article is trying to explain jargon in a simplified form for laymen, not provide textbook definitions for pedants. Also, it's hundreds of feet, not thousands. That's exactly what the article says when it says you need to add a couple of zeros. Also it's not feet everywhere. But they don't use flight levels, do they? They just quote the altitude in metres. |
#14
![]() |
|||
|
|||
![]()
On Fri, 15 Jan 2016 06:46:14 -0600,
wrote: In article , d () wrote: On Fri, 15 Jan 2016 05:25:13 -0600 wrote: In article , d () wrote: On Fri, 15 Jan 2016 09:05:33 -0000 (UTC) Recliner wrote: I think we all know what an Inspector Sands call means, though I never knew where his name came from. This article told me, and some of the other coded I always assumed it was because in times past they'd chuck the sand bucket on a fire. I'm fairly sure I remember one being in a lot of stations when I was a kid. I remember sand buckets on the tube. They looked pretty ancient. IIRC they seemed to have been mostly used as a convenient place to stub out cigarettes. Presumably they now have a better way of putting out fires though one doesn't see too many CO2 extinguishers around so not sure what it might be. I fear they have to be locked away these days. Yes, they were removed from the passenger saloons of underground trains some years ago (as they were being used as weapons), but I gather they're still carried in the cabs. |
#15
![]() |
|||
|
|||
![]()
In article ,
Recliner wrote: On Fri, 15 Jan 2016 12:29:53 +0000, Mike Bristow wrote: ["Followup-To:" header set to uk.transport.london.] In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Not for a layman. This is a piece to explain the jargon. The reason why they're wrong is Quite Interesting; so why get it wrong? Also, it's hundreds of feet, not thousands. That's exactly what the article says when it says you need to add a couple of zeros. "A fancy way of saying how many thousands of feet you are above sea level". It's not. It's a fancy way of saying how many hundreds of feet you are above sea level. Also it's not feet everywhere. But they don't use flight levels, do they? They do use flight levels. The difference between FLx and an altitude of x is one is a certain pressure; the other is the gap between you and sea level. They just quote the altitude in metres. They define it in metres (and use metres for altitudes). -- Mike Bristow |
#16
![]() |
|||
|
|||
![]()
On Fri, 15 Jan 2016 13:03:00 +0000, Mike Bristow
wrote: In article , Recliner wrote: On Fri, 15 Jan 2016 12:29:53 +0000, Mike Bristow wrote: ["Followup-To:" header set to uk.transport.london.] In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Not for a layman. This is a piece to explain the jargon. The reason why they're wrong is Quite Interesting; so why get it wrong? They're not trying to explain jargon or provide complicated explanations of the physics behind the jargon. They're simply providing a quick, simple translation of jargon for ordinary people, not the pedants who inhabit this group. Also, it's hundreds of feet, not thousands. That's exactly what the article says when it says you need to add a couple of zeros. "A fancy way of saying how many thousands of feet you are above sea level". It's not. It's a fancy way of saying how many hundreds of feet you are above sea level. It's a simple way of saying that, and a fancy way of giving the altitude in thousands of feet. Note that they avoiding the jargon term, 'altitude', saying instead, 'how many thousands of feet you are above sea level'. They certainly wouldn't want to get into explaining the difference between barometric, GPS and radar altitudes, nor would it be reassuring for passengers if the height was described as approximate. Also it's not feet everywhere. But they don't use flight levels, do they? They do use flight levels. The difference between FLx and an altitude of x is one is a certain pressure; the other is the gap between you and sea level. They just quote the altitude in metres. They define it in metres (and use metres for altitudes). And so in those countries the height will simply be quoted in metres, with no need to translate a flight level. |
#17
![]() |
|||
|
|||
![]()
When I was last there a few years ago the Phoenix, East Finchley still had a fire tape in the box. Again, I don't Think it was ever used.
In nitrate days the fire shutters over the ports, which should drop automatically by fusible links above each machine served two purposes, to stop the fire spreading to the auditorium, and to prevent the audience from seeing the fire, and panicing. I have projected nitrate film with carbon arcs. |
#18
![]() |
|||
|
|||
![]()
In article ,
Recliner wrote: On Fri, 15 Jan 2016 13:03:00 +0000, Mike Bristow wrote: In article , Recliner wrote: On Fri, 15 Jan 2016 12:29:53 +0000, Mike Bristow wrote: ["Followup-To:" header set to uk.transport.london.] In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Not for a layman. This is a piece to explain the jargon. The reason why they're wrong is Quite Interesting; so why get it wrong? They're not trying to explain jargon or provide complicated explanations of the physics behind the jargon. They're simply providing a quick, simple translation of jargon for ordinary people, not the pedants who inhabit this group. I disagree; but neither of can read the mind of the editor or journalist. Also, it's hundreds of feet, not thousands. That's exactly what the article says when it says you need to add a couple of zeros. "A fancy way of saying how many thousands of feet you are above sea level". It's not. It's a fancy way of saying how many hundreds of feet you are above sea level. It's a simple way of saying that, and a fancy way of giving the altitude in thousands of feet. Nonsense! FL330 is three hundred and thirty hundred feet[1]. It is not three hundred and thirty thousand feet! There's a big difference! Until fairly recently, in the UK it was standard practice to fly at e.g. FL85 (or 8500 feet; not a multiple of 1000). Note that they avoiding the jargon term, 'altitude', saying instead, 'how many thousands of feet you are above sea level'. They certainly wouldn't want to get into explaining the difference between barometric, GPS and radar altitudes, nor would it be reassuring for passengers if the height was described as approximate. Also it's not feet everywhere. But they don't use flight levels, do they? They do use flight levels. The difference between FLx and an altitude of x is one is a certain pressure; the other is the gap between you and sea level. They just quote the altitude in metres. They define it in metres (and use metres for altitudes). And so in those countries the height will simply be quoted in metres, with no need to translate a flight level. Nonsense. You translate to a flight level when you want to use a standard barometric pressure so that everyone at FLxxx is at the same height. You use the real pressure settings when it is important you know the gap between you and the ground (e.g. the mountain peak is at 600', and you're flying at 700'). These two, differing, requirements are independant of the units of measurement. In order to make it clear which one is being used, ATC will always use FLxxx to mean "altitude measured using the standard barometric pressure of 1013.25hPa" and "xxxx feet" or "yyy metres" to mean "altitude using the actual local pressure". It's just that in odd foreign places[2] "FL20" means "600 metres, using 1013.25 hPa as 0", not "2000 feet, using 1013.25 hPa as 0". [1] In eg. the UK and US [2] e.g. Russia, eastern Europe, and China. Except, now I look it up, Russia and some other ex-CIS countries switched to feet in 2011. -- Mike Bristow |
#19
![]() |
|||
|
|||
![]()
On Fri, 15 Jan 2016 14:52:06 +0000, Mike Bristow
wrote: In article , Recliner wrote: On Fri, 15 Jan 2016 13:03:00 +0000, Mike Bristow wrote: In article , Recliner wrote: On Fri, 15 Jan 2016 12:29:53 +0000, Mike Bristow wrote: ["Followup-To:" header set to uk.transport.london.] In article , Recliner wrote: The Real Doctor wrote: "Flight level - "A fancy way of telling you how many thousands of feet you are above sea level. Just add a couple of zeroes. Flight level three-three zero is 33,000 feet."" Is that wrong? [Yes, I know it's the barometric altitude, but that's not something that's normally mentioned.] The use of FLxxx rather altitude is precisely to avoid having to work out what your height above sea level is. In other words, by bringing in "above sea level" they've negated the whole purpose of Flight levels. Not for a layman. This is a piece to explain the jargon. The reason why they're wrong is Quite Interesting; so why get it wrong? They're not trying to explain jargon or provide complicated explanations of the physics behind the jargon. They're simply providing a quick, simple translation of jargon for ordinary people, not the pedants who inhabit this group. I disagree; but neither of can read the mind of the editor or journalist. Also, it's hundreds of feet, not thousands. That's exactly what the article says when it says you need to add a couple of zeros. "A fancy way of saying how many thousands of feet you are above sea level". It's not. It's a fancy way of saying how many hundreds of feet you are above sea level. It's a simple way of saying that, and a fancy way of giving the altitude in thousands of feet. Nonsense! FL330 is three hundred and thirty hundred feet[1]. It is not three hundred and thirty thousand feet! There's a big difference! There is, but I didn't find the original article in the least bit confusing, and I don't suppose its target readers did either. |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Inspector Sands and his pals | London Transport | |||
"Inspector Sands to the Control Room" at Kings Cross today | London Transport | |||
Inspector Sands | London Transport | |||
Inspector Sands diversifies | London Transport | |||
Inspector Sands | London Transport |