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RNAV, MAP

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Hi i'm looking at Navigraph charts. EGKK RWY 08R RNAV

 

I'm confused about the MAP and the MDA. It says for acft that are CAT C the MDA is 700 AGL. In the little box it says MAPt RW 08R? Now i'm confused with these two can someone highlight the differences.

 

Also on the chart it mentions, MISAP later of 2000 1nm THR. What does this mean?

 

Can someone explain all these differences to me. Thanks!

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I don't navigraph charts, but I guess MAP RW08R is an approximate missed approach point.

 

And missed approach procedure can be performed above 2000' in 1nm after runway threshold.

 

Anyway charts are needed to clarify this.

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It's simple, you are allowed to descend to MDA/OCA (in this case 700ft AMSL, not AGL) and fly that altitude to MAPt. Of course, it's not particularly smart to fly in this way in airliner, so you follow RNAV profile. MISAP is procedure for missed approach: Straight ahead until passing 2000or 1NM inboundRW08R whichever is later, turn right heading 179° then as directed by ATC.

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But wouldn't the MAP be at the MDA? Just all confusing.

Lj that reply wasn't for you

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Now i'm confused with these two can someone highlight the differences.

 

MDA is minimum descent altitude - the lowest you can descend.  It is a vertical limit.

MAP (occasionally written "MAPt") is the missed approach point - the farthest you can travel forward until you must go missed.  It's a lateral limit.

 

The MAP is used in conjunction with an vertical (altitude) limit, because if you only had a vertical limit, you could remain at that altitude indefinitely.  In an area of high terrain, this would be very bad.  So, you'll have an altitude limit (MDA/DH/DA/etc), and also a MAP on all approaches.  On some approaches, the MAP may not be specifically depicted on the chart (usually with an 'M') and is implied in hitting DH or DA (this is why they're called decision height/altitude instead of MDA/MDH).

 

 

 


Also on the chart it mentions, MISAP later of 2000 1nm THR. What does this mean?

 

The ICAO chart that I have for it makes it a little more clear.  Basically, it's saying "initiate the missed approach procedure at the latter of either reaching 2000 or being within 1nm of the runway threshold."  In other words, if you're passing 2000 (on the way to 3000) before getting to the MAP, don't make any turns until also getting within 1nm of the MAP; or, if you get to the MAP and haven't passed 2000 (on the way to 3000), wait until passing 2000 before making any turns.

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Right i see now, thanks for that. So you descend to MDA 700 AMSL at that point your at 1.5nm from the RWY is that right? Then you can continue 700 but that would be crazy, 700 feet above the runway and then you try to land?

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Yea, you would require about 6 degrees glide to achieve that, but, that's just in case you see the runway just at the minimums. When you see the rwy, you are allowed to proceed visual bellow MDA.

 

@voske: good, I'm referring to that chart but forgot to post it here! I highly recommend eurocontrol charts for flying in Europe over any other source, as it's free, it's up-to-date, and it's official.

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On some approaches, the MAP may not be specifically depicted on the chart (usually with an 'M')

 

In this case the MAP is depicted on the chart at the runway threshold.

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Why would you continue at MDA if you can't see the runway? It shows to MAPt on that chart in the UK? Why would you continue at 700 and wait till your over the runway?

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You can start to climb earlier, but they want to prevent early turns. Note 5 on the chart is:

 

 

An early initiation of the missed approach may require pilot intervention with the RNAV system in order to comply with the 1NM inbound turn initiation point.

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Why would you continue at MDA if you can't see the runway? It shows to MAPt on that chart in the UK? Why would you continue at 700 and wait till your over the runway?

Some aircraft can do it, for example Cessna 172 would land from MAPt with ease. You do not have to fly all the way to MAPt if you feel it's out of parameters for your aircraft to land. That's why missed approach have that "fly straight ahead to 2000ft or 1nm inbound, whichever is later."

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In this case the MAP is depicted on the chart at the runway threshold.

 

Yes.  I only added that to be complete in my answer.  Note how I specified what the MAP symbol looks like when included on charts (which would be the case here...)

 

 

 

 

 


Then you can continue 700 but that would be crazy, 700 feet above the runway and then you try to land?

 

...one of the many simisms out there.

 

Once you have a visual on the runway, you're flying a visual approach.  So, if you spot the runway at 700 right over the threshold, and you determine that you can keep it in sight during whatever maneuver you need to make to get back into position for a normal approach, then you can do so.  In fact, there are thousands of approaches worldwide in which the approach will dump you off at a very awkward angle to the runway such that you can't make a straight in approach, and are occasionally still at 1000' right over the runway.

 

As I say in one of my videos, approaches are simply instructions on how to get to the airport environment.  If it allows a straight in approach, just thank the chart designer for making it easier for you.

 

 

 


Why would you continue at MDA if you can't see the runway? It shows to MAPt on that chart in the UK? Why would you continue at 700 and wait till your over the runway?

 

Why not?  Going missed means you're flying the whole procedure all over again.  That's a lot of time and fuel.  If you spot the runway at 700 and right over the threshold and determine that you can keep it in sight and make a safe approach from that point, then you should be able to do so.

 

As I always say:

Aviation is not as strict and formulaic as many simmers assume.  There's a TON of discretion allowed to crews.  This is one of those cases.

 

Here's one for you:

All of the approaches to JYO are for Runway 17.  Wind favors 35.  I hit the MDA, but don't have the runway in sight before the threshold.  Should I initiate the missed right as soon as I hit the MDA, or, since I can wait until the threshold, should I wait until then?

 

Since the circling mins are the same as the MDAs on the approaches there, I can fly at the MDA/circling mins as I break off of the approach path and enter into a "traffic pattern" to land on Runway 35, provided I can keep the runway environment in sight during that maneuver.

 

As I mentioned in my last section:

Never forget that approaches are instructions to get you to the airport environment in general.  They may reference a specific runway, but unless they say "circling approaches prohibited" (or circling mins are not published at the bottom), you can use that approach to land on any runway you so choose (provided this is coordinated with the controllers, if the field is controlled).

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Here's one for you:
All of the approaches to JYO are for Runway 17.  Wind favors 35.  I hit the MDA, but don't have the runway in sight before the threshold.  Should I initiate the missed right as soon as I hit the MDA, or, since I can wait until the threshold, should I wait until then?
 
Since the circling mins are the same as the MDAs on the approaches there, I can fly at the MDA/circling mins as I break off of the approach path and enter into a "traffic pattern" to land on Runway 35, provided I can keep the runway environment in sight during that maneuver.
 
As I mentioned in my last section:
Never forget that approaches are instructions to get you to the airport environment in general.  They may reference a specific runway, but unless they say "circling approaches prohibited" (or circling mins are not published at the bottom), you can use that approach to land on any runway you so choose (provided this is coordinated with the controllers, if the field is controlled).

 

Generally, I agree, but if there are few aircraft behind you tightly separated for maximum runway efficiency, there's no way you can do anything but go around. 

 

Great example is MHTG Toncontin Intl, where if you do not have radius to fix feature (PMDG), you have to fly that crazy VOR approach leaving you at really inconvenient place to proceed visually. Even then, company would not allow you to fly whatever you want; they would give you visual procedure- what landmarks to follow.

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Generally, I agree, but if there are few aircraft behind you tightly separated for maximum runway efficiency, there's no way you can do anything but go around. 

 

Great example is MHTG Toncontin Intl, where if you do not have radius to fix feature (PMDG), you have to fly that crazy VOR approach leaving you at really inconvenient place to proceed visually. Even then, company would not allow you to fly whatever you want; they would give you visual procedure- what landmarks to follow.

 

Note the airport I used (JYO is a GA reliever airport - this means it's not a field with high/sequenced traffic on an IFR day).

My final comment was also: "provided this is coordinated with the controllers, if the field is controlled." (So even if it were sequenced, it would still be possible, though not quite in line with courtesies to the flights behind you.  As an alternate example, if everyone was being sequenced to 1R at IAD, and I was flying that approach as a LOC approach and didn't see the runway until very late, I could just as easily sidestep to 1C because it is farther north, affording me more room to descend and land.)

 

While I understand this is the NGX forum, my posts here are clearly on a higher level of discussion than simply airline operations, specifically.  I usually avoid talking about specific airline procedures, specifically because there are some that grant crews a ton of latitude, and then there are others that are awkwardly parental and don't allow any manner of latitude at all (and much less than the regs would allow).

 

 

 

You're absolutely right, but Vernon's issue here (as it is with many of his posts - not that this is a bad thing - he's just learning things a little backwardly) is that he's lost in the fine details and not seeing the bigger picture.  Using specific and limited examples doesn't help to break that.  While JYO is specific, it isn't limited: no sequencing to worry about, it's uncontrolled (affords the PIC more latitude), and offers a unique perspective to why the MDA is minimum descent and not minimum decision altitude (the approaches are only to 17, and there's a need to get to 35 in many cases).

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Yea, living in Europe, I'm unfamiliar with US airports if we do not count the biggest ones, but google is my friend.

 

Anyway, I agree we presented many different details to create one big picture. Hope it was helpful for OP. :smile:

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Yea, living in Europe, I'm unfamiliar with US airports if we do not count the biggest ones, but google is my friend.

 

When I'm talking with local friends, we usually default to "if it isn't a code I recognize, it's probably a smaller field here in the States."  I always forget that, when talking to a worldwide audience, that's probably not the case.

 

 

 


Anyway, I agree we presented many different details to create one big picture. Hope it was helpful for OP.

 

Definitely.  Always good to have a well-rounded view of it all.  And thanks for using that VOR approach as an example.  I was struggling to think of one off the top of my head, even though I knew I'd be able to find one in the Rocky Mountains if I did a little searching.  There are a bunch there (and in Alaska), where you're at some weird angle (occasionally even perpendicular) to the runway at 1000+' AGL because of terrain.

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Thanks for painting the picture lol just needed the light shown on the MDA and MAPt i will continue reading.

 

Happy contrails.

One other thing, below in my drop box pict, there is grey boxes OCA can you descent to these alt at anytime during an app? And level off till the next fix and OCA

One other thing, below in my drop box pict, there is grey boxes OCA can you descent to these alt at anytime during an app? And level off till the next fix and OCA

https://www.dropbox.com/s/mz1gosjfi64h2dh/Photo%2003-10-2014%2016%2012%2050.png?dl=0

One other thing, below in my drop box pict, there is grey boxes OCA can you descent to these alt at anytime during an app? And level off till the next fix and OCA

https://www.dropbox.com/s/mz1gosjfi64h2dh/Photo%2003-10-2014%2016%2012%2050.png?dl=0

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One other thing, below in my drop box pict, there is grey boxes OCA can you descent to these alt at anytime during an app? And level off till the next fix and OCA

 

Yes and no.  Provided no other altitude exists that is higher and part of the procedure, you may.

 

Also: charge your phone  :P

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Iphone 5s you only get a blink of an eye when its fully charged then its dead lol

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Iphone 5s you only get a blink of an eye when its fully charged then its dead lol

 

haha - yeah, they can do that.  I'm usually pretty good about closing apps and all that, so this is me after waking up (and unplugging it) at 5:30 this morning:

IMG_4067.PNG

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My SGS3 battery is holding 2 days  :P  :P

 

Yes, as Kyle said, you can go down to MOC if you want, in your example for Edinburgh, after you pass D12 inbound.

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Yes. I only added that to be complete in my answer. Note how I specified what the MAP symbol looks like when included on charts (which would be the case here...)

 

 

 

 

...one of the many simisms out there.

 

Once you have a visual on the runway, you're flying a visual approach. So, if you spot the runway at 700 right over the threshold, and you determine that you can keep it in sight during whatever maneuver you need to make to get back into position for a normal approach, then you can do so. In fact, there are thousands of approaches worldwide in which the approach will dump you off at a very awkward angle to the runway such that you can't make a straight in approach, and are occasionally still at 1000' right over the runway.

 

As I say in one of my videos, approaches are simply instructions on how to get to the airport environment. If it allows a straight in approach, just thank the chart designer for making it easier for you.

 

 

Why not? Going missed means you're flying the whole procedure all over again. That's a lot of time and fuel. If you spot the runway at 700 and right over the threshold and determine that you can keep it in sight and make a safe approach from that point, then you should be able to do so.

 

As I always say:

Aviation is not as strict and formulaic as many simmers assume. There's a TON of discretion allowed to crews. This is one of those cases.

 

Here's one for you:

All of the approaches to JYO are for Runway 17. Wind favors 35. I hit the MDA, but don't have the runway in sight before the threshold. Should I initiate the missed right as soon as I hit the MDA, or, since I can wait until the threshold, should I wait until then?

 

Since the circling mins are the same as the MDAs on the approaches there, I can fly at the MDA/circling mins as I break off of the approach path and enter into a "traffic pattern" to land on Runway 35, provided I can keep the runway environment in sight during that maneuver.

 

As I mentioned in my last section:

Never forget that approaches are instructions to get you to the airport environment in general. They may reference a specific runway, but unless they say "circling approaches prohibited" (or circling mins are not published at the bottom), you can use that approach to land on any runway you so choose (provided this is coordinated with the controllers, if the field is controlled).

It's been a while since I hung up my CFII spurs, but a RNAV approach doesn't become a visual approach just because you get the airport in sight. I don't think a 360 is "normal maneuver" for a straight in approach. Some approaches are aligned with the runway but have no straight minimums, but that is the exception.

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It's been a while since I hung up my CFII spurs, but a RNAV approach doesn't become a visual approach just because you get the airport in sight. I don't think a 360 is "normal maneuver" for a straight in approach. Some approaches are aligned with the runway but have no straight minimums, but that is the exception.

 

As long as circling mins are published and you remain in the circling approach radius, you're pretty much given discretion as to how you'd like to get down.

 

You're right though that it's not a "visual approach" in the sense of a cleared visual - you'd still fly the missed approach procedure if you lost said visual references.

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