RNAV, MAP

[scandinavian13 5,192]

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).

[g_precentralis 191]

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:

[scandinavian13 5,192]

 

 

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.

[Driver170 42]

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

[scandinavian13 5,192]

 

 

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 

[Driver170 42]

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

[scandinavian13 5,192]

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:

[g_precentralis 191]

My SGS3 battery is holding 2 days   

 

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

[Spin737 102]

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.

[scandinavian13 5,192]

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.

[Copper. 78]

So, how would you get down to the runway (RW08R) if you didn't acquire the required conditions until JUST PRIOR TO THE MAPt? Would you do a circling approach? You'd be too high to attempt a straight in?

 

Brian Nellis

 

http://www.ead.eurocontrol.int/eadbasic/pamslight-F96F8FB131D2478068D6D438DE5FB910/7FE5QZZF3FXUS/EN/Charts/AD/AIRAC/EG_AD_2_EGKK_8-4_en_2014-09-18.pdf

[Spin737 102]

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.

I'd have to see a quote to back that one up for Part91 ops. Part121 ops wouldn't go for it. My 3 airlines don't even allow circling approaches.

[scandinavian13 5,192]

I'd have to see a quote to back that one up for Part91 ops. Part121 ops wouldn't go for it. My 3 airlines don't even allow circling approaches.

 

Right but all the Part 121 stuff is all based off of the company-approved OpSpec, so that's the airline's prerogative, and it's their own call to not allow it.  Sure, it cuts out a lot of discretion that could end up getting them smacked with a lawsuit, but the blame can't be passed back to the FAA on that restriction.  The FAA makes no restriction on it, Part 91 or Part 121.  The operator is adding in "prohibited" or restricting it in some way, and the FAA simply approves that.

 

AIM 5-4-20 covers the basics, and here is an excerpt:

 

Pilots should remain at or above the circling altitude until the aircraft is continuously in a position from which a descent to a landing on the intended runway can be made at a normal rate of descent using normal maneuvers. Circling may require maneuvers at low altitude, at low airspeed, and in marginal weather conditions. Pilots must use sound judgment, have an indepth knowledge of their capabilities, and fully understand the aircraft performance to determine the exact circling maneuver since weather, unique airport design, and the aircraft position, altitude, and airspeed must all be considered. The following basic rules apply:

1. Maneuver the shortest path to the base or downwind leg, as appropriate, considering existing weather conditions. There is no restriction from passing over the airport or other runways.

2. It should be recognized that circling maneuvers may be made while VFR or other flying is in progress at the airport. Standard left turns or specific instruction from the controller for maneuvering must be considered when circling to land.

3. At airports without a control tower, it may be desirable to fly over the airport to observe wind and turn indicators and other traffic which may be on the runway or flying in the vicinity of the airport.

REFERENCE-

AC 90-66A, Recommended Standards Traffic patterns for Aeronautical Operations at Airports without Operating Control Towers.

4. The missed approach point (MAP) varies depending upon the approach flown. For vertically guided approaches, the MAP is at the decision altitude/decision height. Non-vertically guided and circling procedures share the same MAP and the pilot determines this MAP by timing from the final approach fix, by a fix, a NAVAID, or a waypoint. Circling from a GLS, an ILS without a localizer line of minima or an RNAV (GPS) approach without an LNAV line of minima is prohibited.

 

Also, 91.175's references treat it similar to the portion of visual flight at the terminus of any other instrument approach: maneuver as you must within the protected area, but you must maintain a visual on the airport environment.

 

The reference in 121 (121.567) simply refers to the airline's approved OpSpec.  Since Part 91 is so permissive, I'd argue that any operator could submit and get approved an OpSpec just using Part 91 as a basis.  It's easier to say circling approaches are not approved as an operator and not have to worry about all of that, though.

 

Note: the circling area isn't defined in the FARs - it's defined in all of the ACs that make up the TERPS standards, if I recall correctly, but it's a varying radius based on aircraft app category (and now altitude of the MDA, as it was changed in 2012).

 

 

 

Finally, as somewhat of a trump card / TL;DR catch all:

Why would they publish circling minimums for CATs A through E if they didn't expect them to be used?  CAT C and D aren't usually seen outside of the 121 realm.

[Driver170 42]

So, how would you get down to the runway (RW08R) if you didn't acquire the required conditions until JUST PRIOR TO THE MAPt? Would you do a circling approach? You'd be too high to attempt a straight in?

 

Brian Nellis

 

http://www.ead.eurocontrol.int/eadbasic/pamslight-F96F8FB131D2478068D6D438DE5FB910/7FE5QZZF3FXUS/EN/Charts/AD/AIRAC/EG_AD_2_EGKK_8-4_en_2014-09-18.pdf

 

 

Thats what i need to know. I recon if the weather minimums are that low they'll just shoot an ILS app CAT III or II

[g_precentralis 191]

So, how would you get down to the runway (RW08R) if you didn't acquire the required conditions until JUST PRIOR TO THE MAPt? Would you do a circling approach? You'd be too high to attempt a straight in?

 

Brian Nellis

 

http://www.ead.eurocontrol.int/eadbasic/pamslight-F96F8FB131D2478068D6D438DE5FB910/7FE5QZZF3FXUS/EN/Charts/AD/AIRAC/EG_AD_2_EGKK_8-4_en_2014-09-18.pdf

 

As Vernon said, you would probably try ILS if wx conditions are marginally low. Personally, I wouldn't even think of flying RNAV app with ILS available.

 

You'd probably be too high, depending on your aircraft performance. As I said, C172 can do it easily. There's no universal answer, it depends of country, airport, aircraft, operator, pilot, weather, traffic, judgment...