Jepp Question
Thread Starter
Jepp Question
For all you Jepp lovers, I am happy to say Jepp's suck.
For example, can anyone tell me where to find the "eye height over the threshold" (MEHT) for each individual approach light (PAPI/T-VASIS) installation.
For example, for YPKG, in BOTH the ERSA and DAPS it species the eye height is 48FT for both Rwy 11 and Rwy 29 AT-VASIS.
I could not find this information anywhere in the Jepps.
I found the correct definitions (TCH / MEHT) on page 120 in the introduction section of the Jepps, but I have not been able to find the MEHT published on any aerodrome chart/approach plate in the Jeppesens.
On page 120 of the Jepps it says
How good is that ? When known ? Couldn't they be bothered to do some research ?
Considering the fact that PAPI/T-VASIS is designed to have a MEHT of about 50', this means it will be rare to ever find it below 25' and so Jeppesen now got a good excuse not to publish this information.
Can anyone maybe help me where to find this information in the Jepps (information which is so readily available in the Airservices documents) ?
Or will I just have to conclude that Jepps are crap ?
And before anyone tells me to look at the TCH published on the Jepps chart, I have done my research and I am more than happy to conclude that THIS IS NOT the eye height over the threshold of the approach lights.
The majority of the time, the TCH is published at 50' on the Jepp chart however if you look in the ERSA/DAPS, you will notice that the MEHT actually varies and is very rarely at the exact figure of 50'.
If you don't believe me, then compare the Jepp and Airservices chart yourselves.
For example, can anyone tell me where to find the "eye height over the threshold" (MEHT) for each individual approach light (PAPI/T-VASIS) installation.
For example, for YPKG, in BOTH the ERSA and DAPS it species the eye height is 48FT for both Rwy 11 and Rwy 29 AT-VASIS.
I could not find this information anywhere in the Jepps.
I found the correct definitions (TCH / MEHT) on page 120 in the introduction section of the Jepps, but I have not been able to find the MEHT published on any aerodrome chart/approach plate in the Jeppesens.
On page 120 of the Jepps it says
MEHT or TCH is shown (when known) when less than 25' for all other systems (other than 3 bar Vasis) including PAPI.
Considering the fact that PAPI/T-VASIS is designed to have a MEHT of about 50', this means it will be rare to ever find it below 25' and so Jeppesen now got a good excuse not to publish this information.
Can anyone maybe help me where to find this information in the Jepps (information which is so readily available in the Airservices documents) ?
Or will I just have to conclude that Jepps are crap ?
And before anyone tells me to look at the TCH published on the Jepps chart, I have done my research and I am more than happy to conclude that THIS IS NOT the eye height over the threshold of the approach lights.
The majority of the time, the TCH is published at 50' on the Jepp chart however if you look in the ERSA/DAPS, you will notice that the MEHT actually varies and is very rarely at the exact figure of 50'.
If you don't believe me, then compare the Jepp and Airservices chart yourselves.
Last edited by John Citizen; 31st Aug 2004 at 11:00.
How good is that ? When known ? Couldn't they be bothered to do some research ?
Thread Starter
Read Carefully
I wrote
I also wrote
Reynoldsno1:
This information already is in the public domain for Jeppesen to republish. This information does exist on the original chart and the information is available.
Just take a look at the Airservices documents yourselves.
ERSA
DAP's
Lets take a look at Sydney for example and compare.
In the Jeppesens, no MEHT is published and the TCH is published as :
RWY 07 49'
RWY 25 50'
RWY 16R 52'
RWY 34L 50'
RWY 16L 50'
RWY 34R 50'
In the Airservices DAP charts, if you look at the Sydney Aerodrome Chart page 2 or Sydney aerodrome and approach lighting in the ERSA , you will see the following published MEHT's :
RWY 07 44'
RWY 25 45'
RWY 16R 41'
RWY 34L 41'
RWY 16L 47'
RWY 34R 45'
The published TCH figures in the Jepps agree with those published TCH figures in the Airservices documents, however Jeppesen do not publish any MEHT figures. And as you can see, they are not always the same/equal.
I can only conclude the Jepps do not have all the information that the Airservices documents have !! Yet why do the airlines (so called professionals) love them so much if they do not contain all the information ????
Some people might think what is the big deal anyway ?
At one particular International aerdrome in Australia, the MEHT is 61' for one runway and 39' for the other runway. A difference of 22', however I only found this out through the Airservices documents. I could not find the MEHT anywhere in the Jepps.
Now someone might think what is the big deal again ?
If you use some mathematics (trigonometry) here, a MEHT of 39' will lead you to an aiming point of 226m down the runway, and a MEHT of 61' will lead you to an aiming point 355m down the runway.
A 22' difference in the MEHT will lead you to aim / land/ touchdown 129m further down the runway !!!
Some people might think "big deal" again.
However it is important to note that the touchdown zone is only 300m long (extends only 150m beyond the 300m aiming point) and by aiming 129m further down the runway "might" cause you (it happens a lot) to touchdown beyond your touchdown zone. Now in some airlines (as it says so in our ops manual), this is a MUST for a "go-around" if we don't touchdown in the touchdown zone (even though no one does it) !!
That's what the big deal about it all is !!
A higher MEHT is causing us to land further down the runway and I only found out why after consulting the Airservices documents and comparing the MEHT for different runways.
Before someone tells me if you don't like Jepps, then don't use them, unfortunately Jepps are a company requirement where I work.
information which is so readily available in the Airservices documents
if you look in the ERSA/DAPS, you will notice that the MEHT actually varies and is very rarely at the exact figure of 50'
This information already is in the public domain for Jeppesen to republish. This information does exist on the original chart and the information is available.
Just take a look at the Airservices documents yourselves.
ERSA
DAP's
Lets take a look at Sydney for example and compare.
In the Jeppesens, no MEHT is published and the TCH is published as :
RWY 07 49'
RWY 25 50'
RWY 16R 52'
RWY 34L 50'
RWY 16L 50'
RWY 34R 50'
In the Airservices DAP charts, if you look at the Sydney Aerodrome Chart page 2 or Sydney aerodrome and approach lighting in the ERSA , you will see the following published MEHT's :
RWY 07 44'
RWY 25 45'
RWY 16R 41'
RWY 34L 41'
RWY 16L 47'
RWY 34R 45'
The published TCH figures in the Jepps agree with those published TCH figures in the Airservices documents, however Jeppesen do not publish any MEHT figures. And as you can see, they are not always the same/equal.
I can only conclude the Jepps do not have all the information that the Airservices documents have !! Yet why do the airlines (so called professionals) love them so much if they do not contain all the information ????
Some people might think what is the big deal anyway ?
At one particular International aerdrome in Australia, the MEHT is 61' for one runway and 39' for the other runway. A difference of 22', however I only found this out through the Airservices documents. I could not find the MEHT anywhere in the Jepps.
Now someone might think what is the big deal again ?
If you use some mathematics (trigonometry) here, a MEHT of 39' will lead you to an aiming point of 226m down the runway, and a MEHT of 61' will lead you to an aiming point 355m down the runway.
A 22' difference in the MEHT will lead you to aim / land/ touchdown 129m further down the runway !!!
Some people might think "big deal" again.
However it is important to note that the touchdown zone is only 300m long (extends only 150m beyond the 300m aiming point) and by aiming 129m further down the runway "might" cause you (it happens a lot) to touchdown beyond your touchdown zone. Now in some airlines (as it says so in our ops manual), this is a MUST for a "go-around" if we don't touchdown in the touchdown zone (even though no one does it) !!
That's what the big deal about it all is !!
A higher MEHT is causing us to land further down the runway and I only found out why after consulting the Airservices documents and comparing the MEHT for different runways.
Before someone tells me if you don't like Jepps, then don't use them, unfortunately Jepps are a company requirement where I work.
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More importantly for larger aircraft is the 'Wheel height over the Threshold" This (in an operation I am familiar with), is set at a min. 20 feet. As my eyes are 39 feet above the wheels on crossing the T/H, I need to adjust my vertical displacement on the vasis to allow for the difference ie. 1 light fly down on short final, if the MEHT is less than 59 ft. On smaller aircraft types previously flown, it was not unusual to approach at 1 light fly up(on short final), of course always allowing for specific runway circumstances. I am not aware of any rule that says you must fly the vasis centre bar. Touching down on the right spot is the goal, the vasis is an aid to achieve the goal.
Thread Starter
Back Seat Driver
Very good answer Back Seat Driver, however you did not really answer my original question.
You said
Now that sounds great but FIRST where do you find the MEHT published in the Jeppesens anywhere ?
It's a bit difficult to adjust your profile (fly 1 dot high or low) if you do not even know what the MEHT is to start with !
As I said above, I can find the MEHT for each approach light in 2 different Airservices documents (DAPS/ERSA) but nowhere in the Jeppesen documents.
Do you use Jeppesens Back Seat Driver ?
If so, where do you find the MEHT as I could not find it anywhere ?
This was my original question.
You said
1 light fly down on short final, if the MEHT is less than 59 ft
It's a bit difficult to adjust your profile (fly 1 dot high or low) if you do not even know what the MEHT is to start with !
As I said above, I can find the MEHT for each approach light in 2 different Airservices documents (DAPS/ERSA) but nowhere in the Jeppesen documents.
Do you use Jeppesens Back Seat Driver ?
If so, where do you find the MEHT as I could not find it anywhere ?
This was my original question.
Last edited by John Citizen; 1st Sep 2004 at 11:32.
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I may be incorrect, and I'm sure someone will correct me, but isn't the gradient of T-VASIS the same on all runways and that the angle of incidence is focussed in the middle of the touchdown zone?
If that is the case then the MEHT ought to be within the tolerances stated in Jepps for all runways (ie +/- 15ft). Therefore there is no need for there to be a notation for each specific runway.
My understanding of the TCH is that it represents the height above the threshhold when on the ILS. The TCH will vary according to where the glideslope antenna is placed in relation to the runway.
If that is the case then the MEHT ought to be within the tolerances stated in Jepps for all runways (ie +/- 15ft). Therefore there is no need for there to be a notation for each specific runway.
My understanding of the TCH is that it represents the height above the threshhold when on the ILS. The TCH will vary according to where the glideslope antenna is placed in relation to the runway.
Thread Starter
NAMPS
To start with, the MEHT is NOT always within the 15ft tolerance.
Even when it is outside this 15ft tolerance at certain locations, I could not find it specified in the Jeppesens anywhere.
Take a look at Darwin RWY 29. The MEHT is 76ft !
However I could not find this information in the Jepp documents. I had to consult the Airservices ERSA or DAP's
If Airservices can publish this information in 2 different places, then why can't Jeppesen ? That's why I say the Airservices DAPs are better then Jeppesens.
Or maybe Jeppesens do publish this information somewhere but I can not find it.
The MEHT will vary (just like the TCH varies with the ILS) depending on where the approach lights are placed in relation to the runway.
Take a careful look next time you are flying, as the approach lights are not always positoned/focused in the exact middle of the touchdown zone.
Take a look at some of the examples I mentioned above regarding MEHT and "aiming point" (where the lights are positioned on the runway).
A +/- 15ft MEHT tolerance will mean a difference of +/- 88m in the
position of the lights (aim point) !
Considering the touchdown zone is 300m long, this tolerance could place the lights anywhere within 59% of the length of the zone, and not exactly in the middle.
With the lights at Darwin with a MEHT of 76ft, the aim point is at 440m ! This is almost at the very end of the touchdown zone (97% of the way towards the end), which is nowhere near the middle.
So I am sorry to say that the lights are NOT always focussed in the middle of the touchdown zone.
However without any published MEHT information in the Jeppesens, how is a pilot supposed to know this until you actually land somewhere and notice the lights are maybe a little bit out to what you expected (ie. MEHT of 49ft as specified in the Jepps ATC AU-320).
If you consult the Airservices documents, you can work this out rather quickly without having to land there first.
Even when it is outside this 15ft tolerance at certain locations, I could not find it specified in the Jeppesens anywhere.
Take a look at Darwin RWY 29. The MEHT is 76ft !
However I could not find this information in the Jepp documents. I had to consult the Airservices ERSA or DAP's
If Airservices can publish this information in 2 different places, then why can't Jeppesen ? That's why I say the Airservices DAPs are better then Jeppesens.
Or maybe Jeppesens do publish this information somewhere but I can not find it.
The MEHT will vary (just like the TCH varies with the ILS) depending on where the approach lights are placed in relation to the runway.
Take a careful look next time you are flying, as the approach lights are not always positoned/focused in the exact middle of the touchdown zone.
Take a look at some of the examples I mentioned above regarding MEHT and "aiming point" (where the lights are positioned on the runway).
A +/- 15ft MEHT tolerance will mean a difference of +/- 88m in the
position of the lights (aim point) !
Considering the touchdown zone is 300m long, this tolerance could place the lights anywhere within 59% of the length of the zone, and not exactly in the middle.
With the lights at Darwin with a MEHT of 76ft, the aim point is at 440m ! This is almost at the very end of the touchdown zone (97% of the way towards the end), which is nowhere near the middle.
So I am sorry to say that the lights are NOT always focussed in the middle of the touchdown zone.
However without any published MEHT information in the Jeppesens, how is a pilot supposed to know this until you actually land somewhere and notice the lights are maybe a little bit out to what you expected (ie. MEHT of 49ft as specified in the Jepps ATC AU-320).
If you consult the Airservices documents, you can work this out rather quickly without having to land there first.
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Interesting point you raise John Citizen, I will pay attention to the location of the T-VASIS next time!
I guess that it has never made too much of a difference for me as the biggest thing I've ever flown is a Metro/King Air, there is no way I was in danger of ever encountering an over run area, even if I was a bit high and fast over the threshhold.
I guess that it has never made too much of a difference for me as the biggest thing I've ever flown is a Metro/King Air, there is no way I was in danger of ever encountering an over run area, even if I was a bit high and fast over the threshhold.
This may help explain why variances aren't shown on every Jepp chart.
MEHT or TCH is shown in the Jepp's ( If known ) when it is less than 60' for the upwind bar of a (3 bar) vasis or, less than 25' for all other systems including PAPI
Ref JEPP's Introduction 120
MEHT or TCH is shown in the Jepp's ( If known ) when it is less than 60' for the upwind bar of a (3 bar) vasis or, less than 25' for all other systems including PAPI
Ref JEPP's Introduction 120
Thread Starter
Bill Smith
I already mentioned this in my first post.
I have already said this :
I also said
I have already said this :
Considering the fact that PAPI/T-VASIS is designed to have a MEHT of about 50', this means it will be rare to ever find it below 25' and so Jeppesen now got a good excuse not to publish this information.
I can only conclude the Jepps do not have all the information (ie MEHT) that the Airservices documents have !! Yet why do the airlines (so called professionals) love them so much if they do not contain all the information ????
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For all you Jepp lovers, I am happy to say Jepp's suck.
Shame you ruined an opportunity to present an interesting discussion topic in a 'professional' bulletin board by acting like a mindless member of a cheersquad.
Jepp v ASA
Boeing v Airbus
Jet v Prop
Turbine v Piston
Female v Male pilots
Ford v Holden
Australian v Imported
Or...
"This company is rubbish. In Ansett/at Singapore/in Jets/in the Navy/in the States we used to fly it [fill in the blanks]"
Same thing.
Big deal.
Are we interested to hear about differences?
Yes. All good stuff for the professional toolbox between the ears.
Listen to someone who says "Mine is the only way. Yours is crap."?
No.
Have only shown yourself to be incapable of dealing with relativities.
Keep your petty hates and prejudices to yourself. Try to remember this is a forum for professionals. A true pro doesn't jump on bandwagons and bag the crap out of any other method. A true pro assesses what is being asked of him in company docs and procedures, and measures it against personal knowledge and standards. Then if there is no great disconnect between what is being asked and what the professional knows about his/her subject, the professional goes and does the job the way he or she is asked to do it.
Declaring yourself to be incapable of or uncomfortable in working with certain kinds of equipment/documents/pilots just shows that you are limited, not the equipment/docs/other pilots.
Last edited by ITCZ; 6th Sep 2004 at 07:23.
Thread Starter
ITCZ
You say
Thanks.
I thought it would be a good topic/question/valid opinion to post and so I did.
I admit maybe I was being a bit prejudice, but this is only because other Jepp lovers have been so prejudice Airservices documents in the past/towards me.
Many years ago (1996) my flying instructor who loved Jepps so much told me how the DAPS were CRAP and he just loved the Jepps so much. He said the Jepps must be good/better because airline pilots use them. Is that a valid reason ?
He also came up with a few other reasons why the Jepps are so much better, such as the texture of the paper and other reasons which I thought were not valid.
It is the content of the document and not who uses them that should be considered in determining their quality.
I would love to see this instructor now and ask him if he can find the MEHT on the Jepps chart anywhere ? He would probably still tell me DAPs are crap.
Maybe my prejudice is aimed towards this instructor and not towards other pilots, and so I apologise.
Though I have seen this topic of "Jepps vs Daps" debated many time on pprune and so I thought I would have my "valid" say. I have backed up my opinion with proof (important operational information), and not other reasons, such as quality of paper etc.
I work in a multi crew environment myself and I well aware of the need to be accomodating to others, and I believe I am.
Its is these other pilots who have been so unaccomodating towards me in the past.
So this post was aimed towards them in a way, I hope they read it.
If only I could find them now and discuss it face to face.
Good for you
I thought it would be a good topic/question/valid opinion to post and so I did.
I admit maybe I was being a bit prejudice, but this is only because other Jepp lovers have been so prejudice Airservices documents in the past/towards me.
Many years ago (1996) my flying instructor who loved Jepps so much told me how the DAPS were CRAP and he just loved the Jepps so much. He said the Jepps must be good/better because airline pilots use them. Is that a valid reason ?
He also came up with a few other reasons why the Jepps are so much better, such as the texture of the paper and other reasons which I thought were not valid.
It is the content of the document and not who uses them that should be considered in determining their quality.
I would love to see this instructor now and ask him if he can find the MEHT on the Jepps chart anywhere ? He would probably still tell me DAPs are crap.
Maybe my prejudice is aimed towards this instructor and not towards other pilots, and so I apologise.
Though I have seen this topic of "Jepps vs Daps" debated many time on pprune and so I thought I would have my "valid" say. I have backed up my opinion with proof (important operational information), and not other reasons, such as quality of paper etc.
I work in a multi crew environment myself and I well aware of the need to be accomodating to others, and I believe I am.
Its is these other pilots who have been so unaccomodating towards me in the past.
So this post was aimed towards them in a way, I hope they read it.
If only I could find them now and discuss it face to face.
John Citizen,
Way to let some kind of past disagreements possibly ruin a good thread.
Personally I prefer the Jepps. Reasons;
1. I find the ammendments easier to deal with (I have run both concurrently and had to give up on the ASA version because I couldn't easily tell if my docs were current or not).
2. The entire AIP is contained within two folders.
3. I happen to be at a stage in my career where the MEHT is irrelevant so I hadn't noticed that they were not available.
I am quite comfortable with the fact that you prefer the DAPS etc and will not waste my time or yours discussing why one is better than the other. If you prefer the DAPS that is fine by me.
I am interested to know the answer to your question and am hoping that one will be forthcoming in this thread.
However, statements like "Jepps are crap" just get some people's hackles up and threaten to overide what could be a constructive thread.
ITCZ,
Come on, it's not hard to pick out the meat from this OP, it takes two to tango etc, if you were to clinically answer the guy's question then the whole Jepp vs ASA thing need not be an issue.
Two questions (from someone who likes Jepps);
1. Is the MEHT figure operationally useful?
2. If so, why do the Jepps not have it (or do they - where?)?
Way to let some kind of past disagreements possibly ruin a good thread.
Personally I prefer the Jepps. Reasons;
1. I find the ammendments easier to deal with (I have run both concurrently and had to give up on the ASA version because I couldn't easily tell if my docs were current or not).
2. The entire AIP is contained within two folders.
3. I happen to be at a stage in my career where the MEHT is irrelevant so I hadn't noticed that they were not available.
I am quite comfortable with the fact that you prefer the DAPS etc and will not waste my time or yours discussing why one is better than the other. If you prefer the DAPS that is fine by me.
I am interested to know the answer to your question and am hoping that one will be forthcoming in this thread.
However, statements like "Jepps are crap" just get some people's hackles up and threaten to overide what could be a constructive thread.
ITCZ,
Come on, it's not hard to pick out the meat from this OP, it takes two to tango etc, if you were to clinically answer the guy's question then the whole Jepp vs ASA thing need not be an issue.
Two questions (from someone who likes Jepps);
1. Is the MEHT figure operationally useful?
2. If so, why do the Jepps not have it (or do they - where?)?
So are they on page 10-9a like I said or are they not?
I havent got a full set anymore. I know they're there for SYD, MEL, BNE etc. what about everywhere else?
Put me out of my misery someone please!!!
I havent got a full set anymore. I know they're there for SYD, MEL, BNE etc. what about everywhere else?
Put me out of my misery someone please!!!