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Author Topic: KJFK Approach, Carnarsie Visual Transition 13L. Speedbird B777 (VIDEO)  (Read 28876 times)
Studentpilo
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« Reply #15 on: February 25, 2007, 10:43:34 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue
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Greg01
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« Reply #16 on: February 26, 2007, 02:45:29 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue

You mean it has no DA.  Wink

Greg
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atav
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« Reply #17 on: February 26, 2007, 03:56:03 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue

You mean it has no DA.  Wink

Greg

you know your stuff!


how are you guys? first post for me
-Alex
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Greg01
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« Reply #18 on: February 26, 2007, 04:49:23 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue

You mean it has no DA.  Wink

Greg

you know your stuff!


how are you guys? first post for me
-Alex

Thanks... smiley

I hope so, i have to take a written test on Saturday. Little nervous.

Thanks and welcome aboard.

Greg
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Studentpilo
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« Reply #19 on: February 26, 2007, 05:50:13 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue

You mean it has no DA.  Wink

Greg

Technically it has neither  grin
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Greg01
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« Reply #20 on: February 26, 2007, 05:55:18 PM »

Correct. It does, however, have an "alert altitude" at 100 feet.

Greg
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atav
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« Reply #21 on: February 26, 2007, 06:17:55 PM »

Except that a CAT IIIC approach has no MVA/DH  tongue

You mean it has no DA.  Wink

Greg

you know your stuff!


how are you guys? first post for me
-Alex

Thanks... smiley

I hope so, i have to take a written test on Saturday. Little nervous.

Thanks and welcome aboard.

Greg

Well thanks for welcoming me.
And I wish you luck on your test!!

-Alex
« Last Edit: February 26, 2007, 06:25:11 PM by atav » Logged

Greg01
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« Reply #22 on: February 26, 2007, 06:22:53 PM »

My pleasure and thank you!  Wink

Greg
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KSYR-pjr
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« Reply #23 on: February 26, 2007, 06:58:05 PM »

You mean it has no DA.  Wink

DA, Greg?   I think you might be mixing up the two acronyms.

DH, as in Decision Height, is what typically applies to precision approaches, such as an ILS approach.
MDA, as in Minimum Decent Altitude, is what typically applies to non-precision approaches.

In regards to types of CAT III approaches and published DHs, both CAT IIIA and CAT IIIB can have only RVR minimums without a published DH.

Here's an example from JFK (NY).  Note that the minimums table at the bottom only indicate an RVR minimum but no DH: 

http://www.myairplane.com/databases/approach/pdfs/00610I4RC3.PDF




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Regards, Peter
ATC Feed:  Syracuse (KSYR), NY
Greg01
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« Reply #24 on: February 26, 2007, 07:13:38 PM »

Peter, at this stage in the game, i hope i'm not mixing these things up.

DA = Decision Altitude. This refers to the MSL altitude printed on charts.

DH = Decision Height is a distance (height) above the touchdown zone and is reserved for approaches that use radar altimetry for the missed approach point.

For the category I ILS approach, the missed point is an altitude and is listed in MSL figures. The number in parenthesis is the height above the touchdown zone and there is a difference between them. You cannot use that height for that approach, as the terrain below you is not factored at that point. The height is for information only, the altitude (DA) is the limiting factor of the approach.

So DA is the ILS MAP for CAT I approaches.

Minor differences, but still differences.

Greg
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KSYR-pjr
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« Reply #25 on: February 26, 2007, 07:54:28 PM »

So DA is the ILS MAP for CAT I approaches.

From the US Controller/Pilot Glossary:

Quote
DECISION HEIGHT- With respect to the operation of aircraft, means the height at which a decision must be made during an ILS, MLS, or PAR instrument approach to either continue the approach or to execute a missed approach.

(http://www.faa.gov/airports%5Fairtraffic/air%5Ftraffic/publications/atpubs/PCG/D.HTM)
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Regards, Peter
ATC Feed:  Syracuse (KSYR), NY
Greg01
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« Reply #26 on: February 26, 2007, 07:58:47 PM »

Quote
DECISION ALTITUDE/DECISION HEIGHT [ICAO]- A specified altitude or height (A/H) in the precision approach at which a missed approach must be initiated if the required visual reference to continue the approach has not been established.

Note 1: Decision altitude [DA] is referenced to mean sea level [MSL] and decision height [DH] is referenced to the threshold elevation.

Note 2: The required visual reference means that section of the visual aids or of the approach area which should have been in view for sufficient time for the pilot to have made an assessment of the aircraft position and rate of change of position, in relation to the desired flight path

Right above from where you quoted. Sure the numbers for the DH are printed, but that can't be verified because the terrain wasn't taken into account if using a radar altimeter.

Greg
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KSYR-pjr
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« Reply #27 on: February 26, 2007, 08:43:01 PM »

Ha... it appears as if I turned this subject into a game of semantics and that was not my intent.  Sorry 'bout that.   

I was attempting to point out that the DH is "officially" defined as a point at which the missed starts, which if I had read your previous post correctly, you suggested it didn't.







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Regards, Peter
ATC Feed:  Syracuse (KSYR), NY
sunburn
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« Reply #28 on: February 26, 2007, 09:05:31 PM »

oh please... carry on! i'm finding this interesting reading as I have very little knowledge about flying an aircraft, except for the very basics. I'm very much a newbie so reading all this terminology and semantics is fascinating!
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Greg01
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« Reply #29 on: February 26, 2007, 09:16:14 PM »

My apologies, as well.

Okay, Peter, i see what you're saying. I neglected to reread my previous posts.

The DH is indeed where the missed starts, but not on all approaches.

When you read this chart (at the bottom): what are the minimums?

For the S-ILS, I see a DA of 928 MSL. The 200 is the height above the touchdown. Because the terrain is not factored in, it's not technically a DH. If it said sometime like: RA 200, then it would be a DH.

I know it sounds nit-picky, and i apologize, but i was taught to always pay attention to the details.

I appreciate the challenge, i really do enjoy researching items when a question is brought up.

TO cap my post, yes, the DH is one possible MAP for an ILS.

Thanks,
Greg
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