Some basic air law questions.
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Some basic air law questions.
Hi folks, studying is off to a good start and progressing well with the J. Pratt books. Currently on Air law, i've been noting some questions as i go and would appreciate some comments.
I have searched the forums and answered most of my questions but the ones below i couldn't probably due to not knowing exactly what is best to search for.
Anyway, with regards to units, there seems to be an awful lot of switching between feet and metres which could get confusing. For example in Airspace classes and VFR Minima, (law56 J. Pratt, PPL2) class D airspace has VFR Minima listed as:
At and above FL100; 8km flight vis, 1500m horizontally clear of cloud and 1000ft vertically clear of cloud.
Is this correct? Maybe i'm just paranoid but as an electronic engineer, mixing units like this leaves me suspicious!
The same thing is used in low flying rules:
"Aircraft may not take off and land within 1000m of an organised open air assembly of more than 1000 people..."
This is in the same paragraph as talking about 1000ft above the assembly.
Very confusing indeed. I'd get shot for doing that in my job!
I have searched the forums and answered most of my questions but the ones below i couldn't probably due to not knowing exactly what is best to search for.
Anyway, with regards to units, there seems to be an awful lot of switching between feet and metres which could get confusing. For example in Airspace classes and VFR Minima, (law56 J. Pratt, PPL2) class D airspace has VFR Minima listed as:
At and above FL100; 8km flight vis, 1500m horizontally clear of cloud and 1000ft vertically clear of cloud.
Is this correct? Maybe i'm just paranoid but as an electronic engineer, mixing units like this leaves me suspicious!
The same thing is used in low flying rules:
"Aircraft may not take off and land within 1000m of an organised open air assembly of more than 1000 people..."
This is in the same paragraph as talking about 1000ft above the assembly.
Very confusing indeed. I'd get shot for doing that in my job!
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It's to do with whether the distance is in the horizontal or vertical plane.
Distances in the horizontal plane are always expressed in metres (e.g. forward visibility).
Distances in the vertical plane are always expressed in feet (e.g. altitude).
Hope that helps
Distances in the horizontal plane are always expressed in metres (e.g. forward visibility).
Distances in the vertical plane are always expressed in feet (e.g. altitude).
Hope that helps
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Yeah i noticed the connection, is there an historical reason behind that? Or just established convention?
It's less confusing when you realise the vertical/horizontal connection! Feel stupid now for asking! Doh!
It's less confusing when you realise the vertical/horizontal connection! Feel stupid now for asking! Doh!
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That bit I'm not sure on, I'm sure somebody will be able to give an answer though.
Most former Soviet bloc countries use metres for altitude instead of feet, so I would imagine it's just established convention.
Most former Soviet bloc countries use metres for altitude instead of feet, so I would imagine it's just established convention.
Last edited by gg190; 30th Jul 2011 at 18:19. Reason: spelling
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Wait until you get to fuel. There's five different units commonly used to identify how much you've got on board (two based on volume and three based on weight - although one of those three is not very commonly used in light aircraft).
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Maybe i'm just paranoid but as an electronic engineer, mixing units like this leaves me suspicious
The fact that most youngsters these days ie anyone under 45 don't have a clue what 500ft or 1000ft look like.
They tend to do horizontal distances in meters and heights in ft. There are a few specials like rule 5 which is 500ft away from any person etc this is more like a bubble around the aircraft so its horizontal or vertical or a bit of both with a slant.
Then you have speeds in Knts distance in Nm so its a real hodge podge mixture. But once you get your head round it its not a problem.
If you think pilots have it bad you should see some of the mixtures the engineers have to put up with. Metric diameter/length allen studs with imperial threads and profiles with an Imperial key needed for the top. You look at them and measure it and think that will be a M8 FS and then when you get it under a lens its some funny UNF thing.
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Haha, yeah i'm glad i'm not a mechanical engineer!
Although in saying that, all my dimensions at work are in um/nm and everything down to fF (10^-15). Mind bogglingly small stuff. And we're the 'large scale' power guys!
Anyway, thanks for the replies, i have another question!
In class D airspace below 3000ft AMSL, <140knots IAS:
5km visibility, clear of cloud and surface in sight...
Is that 5km clear of cloud? Or just 'clear of cloud' with the 5km referring to visibility?
Thanks!
Although in saying that, all my dimensions at work are in um/nm and everything down to fF (10^-15). Mind bogglingly small stuff. And we're the 'large scale' power guys!
Anyway, thanks for the replies, i have another question!
In class D airspace below 3000ft AMSL, <140knots IAS:
5km visibility, clear of cloud and surface in sight...
Is that 5km clear of cloud? Or just 'clear of cloud' with the 5km referring to visibility?
Thanks!
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Vertical stuff is normally in feet, except in Russia, and in the JAA IR exams where they randomly throw in metres in the hope that you will misread the question and forget to multiply by 3.2 
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ATS Classifications
Download the pdf from this link...
http://www.caa.co.uk/docs/64/2008901...ficationV3.pdf
It shows all the information of distances VFR + IFR and Airspace Classification.
http://www.caa.co.uk/docs/64/2008901...ficationV3.pdf
It shows all the information of distances VFR + IFR and Airspace Classification.
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IO540, thanks for the heads up! I'll definitely be on the lookout for that. They used to do that to us at university, trying to trick us with units! Hopefully i'm still used to it.
Thanks for clearing that up thing.
JimA_UK, printed and put on the wall!
Thanks for clearing that up thing.
JimA_UK, printed and put on the wall!
