Where's the MAP on this, and why?

MAKG1 said:
No. There are quite a number of instrument approaches at not-very-long runways. You will never make it at KPAO GPS 31, for instance. That's a 460 foot straight-in minimum with the MAP at the threshold, and a 2400 foot runway. Or KRHV RNAV Y 31R (that one has a 1200 AGL minimum on a 2700 foot runway -- yikes!). Or O69 RNAV 29 (620 feet over a 3600 foot runway, for LNAV minimums).

You don't have to operate out of IAD to find instrument approaches anymore. They are at quite a lot of smaller airports.
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A standard C150 would easily land all of those.

edit: the RHV RNAV Y would be a bit hairy, but 620ft over 3600ft runway is easy. So is 460ft and 2400ft.
 
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midlifeflyer said:
It's so funny. There seem to be two "approaches" to the chart in this thread:

1. Learn how to read it.
2. whine about it not being the way you would write it.
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I think the conversation results from a lack of clarity in the FAA chart. RNAV approaches have a dedicated symbol for the MAP. But for the traditional precision approaches, the profile view depiction favors the precision vs. non-precision route. The Jepp chart example posted above seems clearer.

Btw aterpster, thanks for catching my error.
 
MAKG1 said:
You can't specify the MAP is the end of the runway if people may not be able to see it. You have to specify it some other way. Like DME.
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What are you talking about? As stated in the thread a lot of approaches have the MAP at the end of the runway.
 
dmspilot said:
What are you talking about? As stated in the thread a lot of approaches have the MAP at the end of the runway.
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True, but there has to be some way of identifying that point without seeing it out the window. Examples include an RNAV waypoint, a DME distance, or a timing table on the chart.
 
Palmpilot said:
True, but there has to be some way of identifying that point without seeing it out the window.
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No kidding. Still doesn't explain the point of the quoted post. Did anyone think you have to be able to see the MAP out the window? That would defeat the purpose of the concept of a MAP. The runway is the MAP in numerous examples and the GPS knows where the runway is.
 
WillFly4Food said:
I think the conversation results from a lack of clarity in the FAA chart. RNAV approaches have a dedicated symbol for the MAP. But for the traditional precision approaches, the profile view depiction favors the precision vs. non-precision route. The Jepp chart example posted above seems clearer.
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That's my point. I don't see the lack of clarity. I look at that chart and see the MAP is the runway waypoint and understand that on an FAA APV chart, whether LPV or ILS, the solid to dotted transition point approximates the location of DH on glidepath, and not the nonprecision MAP.

The nonprecision MAP needs to be identifiable and, whether the solid line in the profile continues all the way to the runway or not is pretty much irrelevant since it doesn't tell me that (that may have been the point of the "looking out the window" discussion). There has to be a means of identification other than the solid line in the profile.

Could the designer of the chart have made a different choice? Sure. Jepp made a different choice, making explicit what the FAA leaves implicit. Do I need to "like" one of them better than the other to understand both? No.
 
Palmpilot said:
Any idea what the reason could have been for equipping the ILS with its own DME, instead of using the one on the San Jose VOR?
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That has been the policy for many years, where funding is available. Funding is usually available at Part 139 airports. In most airline airplanes the DME is frequency paired with the VOR or LOC frequency; i.e., the DME cannot be tuned separately. Using the DME from the SJC VOR for the ILS would prevent both pilots from displaying the ILS. That is contrary to best operating practices. As more airline airplanes are equipped with RNAV, this issue has mitigated.
 
I didn't say there weren't short runways with approaches, I was just agreeing that most are longer. You find me an ILS at a place with less than 3000'. The Navion only needs 850' and the full flap/power off/gear down angle of descent is pretty fierce.
 
midlifeflyer said:
Could the designer of the chart have made a different choice? Sure. Jepp made a different choice, making explicit what the FAA leaves implicit. Do I need to "like" one of them better than the other to understand both? No.
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Jeppesen charts become a necessity rather than a "like" for flight operations outside the U.S. Also, the FAA won't chart special instrument approach procedures in the U.S. Finally, Jepp provides the airlines the option for tailored charts and a given carrier's manual is customized to their authorized airports. It's tougher for the corporate flight department that flies most of the world. Some of them have to subscribe to Jepp's worldwide service. $$$$$$
 
dmspilot said:
No kidding. Still doesn't explain the point of the quoted post. Did anyone think you have to be able to see the MAP out the window? That would defeat the purpose of the concept of a MAP. The runway is the MAP in numerous examples and the GPS knows where the runway is.
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My guess is that what I wrote was the point he was trying to make.
 
dmspilot said:
. The runway is the MAP in numerous examples and the GPS knows where the runway is.
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In ground-based NPA's without DME and off-airport nav aid, even the timing table knows where the runway is. :)
 
flyingron said:
I didn't say there weren't short runways with approaches, I was just agreeing that most are longer. You find me an ILS at a place with less than 3000'. The Navion only needs 850' and the full flap/power off/gear down angle of descent is pretty fierce.
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You find me an ILS with a MAP over the threshold.

The discussion was about MAPs, which means nonprecision approaches. Not ILSs.

LNAV approaches have multiplied quite a lot over recent years. There are A LOT of them at smaller airports.

Some of them have pretty high minimums, too, due to terrain or obstructions. KDVO GPS 13 is another one you won't make on a straight-in. The minimum is 1000 feet (both AGL/MSL) because the missed approach is forced over four 500 foot radio towers by terrain. 3300 foot runway notorious for squirrely winds (terrain, again).

Honestly, I've flown most of the local approaches around here, and having a nonprecision approach with a high minimum and a MAP directly over the threshold of a relatively short runway is not at all rare. About all you can do is CTL. Trying to slip 1000 feet onto a 1/2 mile runway is a great way to overrun.
 
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No need to even slip in the Navion. 3000 feet is more than enough with full flaps and gear out. Most of our MDAs are lower than 1000' anyhow. No, I agree that it's not a universal truth, but there are more runways where you can drop out of the MDA at the threshold and make it than not I suppose.
 
aterpster said:
...the FAA won't chart special instrument approach procedures in the U.S. ....
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No they won't, but Jepp isn't the only game in town, just the most expensive one. We found an outfit in Canada that did an NOS-style approach plate for one of our SIAPs, for a lot less than Jepp. In the end, I think we got Jepp to lower their price a bit and we switched back to them for the last update.
 
aterpster said:
In ground-based NPA's without DME and off-airport nav aid, even the timing table knows where the runway is. :)
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Yeah, it knows. About how "big" is the MAP when the approach is built? How much tolerance is there for pilot error in misjudging exact ground speed and time?
 
aterpster said:
Jeppesen charts become a necessity rather than a "like" for flight operations outside the U.S. Also, the FAA won't chart special instrument approach procedures in the U.S. Finally, Jepp provides the airlines the option for tailored charts and a given carrier's manual is customized to their authorized airports. It's tougher for the corporate flight department that flies most of the world. Some of them have to subscribe to Jepp's worldwide service. $$$$$$
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All true but not relevant to my flying.

Like many others, I learned with NACO and later developed a preference for Jepp (especially since the company was about a mile from my house and I had friends there). I switched back to FAA charts when the EFB came along and ultimately decided it didn't really make that much difference in my world,

I'm planning a recreational flight in Canada on an upcoming vacation. It's going to be with a local CFI and VFR but my curiosity has me taking the opportunity to familiarize myself with their charts. Plenty of differences but other than a couple of different acronyms here and there, I don't see a huge problem understanding them either.

I'm not special, except perhaps I don't get worked up over minor differences as much as some others.
 
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midlifeflyer said:
I'm not special, except perhaps I don't get worked up over minor differences as much as some others.
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...and you felt it neccesary to stop by and tell us all about it while adding nothing.

"everyone knows" how to identify a non precision map but no one can point to any document anywhere that tells how to positively identify the MAP on an faa iap. aterpster posted a text document that calls it out by name, but its not something i can buy at the local fbo. id bet most pilots have never seen anything like it.

Here's what im looking for: a link to a document, page number and paragraph that start with text similar to "The missed approach point may be located on instrument procedure diagrams via the.....". ive looked, and didnt find anything. i asked the " experts" here and still nothing except "just is".

i find that odd.
 
Mistake Not... said:
...and you felt it neccesary to stop by and tell us all about it while adding nothing.

"everyone knows" how to identify a non precision map but no one can point to any document anywhere that tells how to positively identify the MAP on an faa iap. aterpster posted a text document that calls it out by name, but its not something i can buy at the local fbo. id bet most pilots have never seen anything like it.

Here's what im looking for: a link to a document, page number and paragraph that start with text similar to "The missed approach point may be located on instrument procedure diagrams via the.....". ive looked, and didnt find anything. i asked the " experts" here and still nothing except "just is".

i find that odd.
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Here you go.

https://www.faa.gov/air_traffic/fli...aero_guide/media/Chart_Users_Guide_12thEd.pdf

page 83, Lower left hand corner.

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Sent from my iPad using Tapatalk
 
luvflyin said:
Yeah, it knows. About how "big" is the MAP when the approach is built? How much tolerance is there for pilot error in misjudging exact ground speed and time?
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Depends on the fix displacement error of the FAF. It's in Chapter 2 of 8260.3C. All missed approach points have fix displacement errors built in. Even for a DME fix, it is at least plus-or-minus 1/2 mile.
 
MAKG1 said:
You find me an ILS with a MAP over the threshold.

The discussion was about MAPs, which means nonprecision approaches. Not ILSs.
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Here's what TERPs says about the MAP:

MAP. The MAP specified in the procedure may be the point of intersection of a specific glidepath with a DA, a navigation facility, a fix, or a specified distance from the PFAF. A specified distance may not be more than the distance from the PFAF to the usable landing surface. The MAP must not be located prior to a VDP. Specific criteria for the MAP are contained in the appropriate chapters.
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aterpster said:
Depends on the fix displacement error of the FAF. It's in Chapter 2 of 8260.3C. All missed approach points have fix displacement errors built in. Even for a DME fix, it is at least plus-or-minus 1/2 mile.
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Grrr. But I don't wanna look it up for myself, lol. I was just wondering how big a difference there generally was between those based on "fixes" and those based on time. I'd think it was pretty big.
 
@aterpster, can you post two IAP source documents, the official regulatory documents that define the IAP fir a GPS and an ILS/LOC. They might help to understand the design of the charts and the location of the MAP.
 
midlifeflyer said:
@aterpster, can you post two IAP source documents, the official regulatory documents that define the IAP fir a GPS and an ILS/LOC. They might help to understand the design of the charts and the location of the MAP.
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You can go to the FAA's IFP Gateway, select the airport of your choice (including the "K"). When you get to your selected airport, then select the NDBR tab and the source will usually be there including abbreviated amendments, if any. I say "usually" because maintenance of the NDBR tab is less than 100%.

https://www.faa.gov/air_traffic/flight_info/aeronav/procedures/
 
Actually, it doesn't care if you put the K or not. Both forms of the identifier are in the record.
 
flyingron said:
Actually, it doesn't care if you put the K or not. Both forms of the identifier are in the record.
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Indeed so. I access the site everyday. It used to require the leading K. I have no idea when they changed it. Even when the leading "K" was required, it was not at other sites such as terminal instrument procedures and the digital chart supplement. As Alfred E. Neuman would say, "Go figure."
 
Mistake Not... said:
...and you felt it neccesary to stop by and tell us all about it while adding nothing.

"everyone knows" how to identify a non precision map but no one can point to any document anywhere that tells how to positively identify the MAP on an faa iap. aterpster posted a text document that calls it out by name, but its not something i can buy at the local fbo. id bet most pilots have never seen anything like it.

Here's what im looking for: a link to a document, page number and paragraph that start with text similar to "The missed approach point may be located on instrument procedure diagrams via the.....". ive looked, and didnt find anything. i asked the " experts" here and still nothing except "just is".

i find that odd.
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I followed the link Wally provided and looked at the source document for a familiar approach, an ILS or LOC where, as usual, the missed in the profile view starts at the approximation of DA although the LOC missed is at the threshold. Sure enough, the MAP is identified as being at the threshold.

So yes, while a Jepp specifically identifies it on the chart, what "everyone knows" is correct.

And, yes again, while I get as annoyed as anyone else when I see something on a chart that I can't find a legend item for, I guess there are some basics that "just is" and are part of learning how to read the chart.
 
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