Jump to content

What is the correct procedure to fly a VNAV approach?


Recommended Posts

I'm trying the RNAV(RNP) Y approach to runway 31L at KPSP.  VNAV kind of works up until the point where the synthetic glideslope should be intercepted, provided one lowers the target altitude setting to below the runway altitude.  Most aircraft permit the target altitude to be set to the glideslope intercept altitude for this type of approach.  Is VNAV actually the wrong way to fly a VNAV(RNP) approach?  How does one select other approach modes?

Edited by cwjohan
Link to comment
Share on other sites

Unlike other aircraft types in the Collins auto flight system VNAV is a modifier on the standard vertical modes (VS, FLC, etc.). It basically instructs the system to respect altitude constraints in the flight plan, and if enabled, use speed targets from the FMS. When descending in VPATH on an arrival and initial approach, similar to an ILS, once the plane is flying towards the final approach point for the RNAV/RNP then one can push the APPR button and VGP will arm/capture. Once active the plane will descend on the final glide path below the preselected altitude. Hope that helps.

  • Upvote 2
Link to comment
Share on other sites

14 hours ago, cwjohan said:

I'm trying the VNAV(RNP) Y approach to runway 31L at KPSP.  VNAV kind of works up until the point where the synthetic glideslope should be intercepted, provided one lowers the target altitude setting to below the runway altitude.  Most aircraft permit the target altitude to be set to the glideslope intercept altitude for this type of approach.  Is VNAV actually the wrong way to fly a VNAV(RNP) approach?  How does one select other approach modes?

Just to clarify, it's an RNAV (RNP) The only other approach type available for PSP 31L is a VOR approach. Go to DEP/ARR to select the approach. What altitude did you originally have set, and did you arm the approach?

Link to comment
Share on other sites

Posted (edited)
On 3/22/2022 at 5:40 AM, JJM said:

Just to clarify, it's an RNAV (RNP) The only other approach type available for PSP 31L is a VOR approach. Go to DEP/ARR to select the approach. What altitude did you originally have set, and did you arm the approach?

If I recall correctly, I had the the altitude set for 4000 ft as the RNAV (RNP) Y approach chart indicates for TEVUC.  After passing TEVUC, I probably was too slow to reduce the constraint to 2900 ft.  Well before JISOP, I reduced the selected altitude to 2900 ft as indicated by the approach chart as the glideslope intercept altitude.  I immediately pressed VS and set a high descent rate to try to get down to 2900 ft before JISOP.  Shortly after pressing VS, I also pressed APPR to arm the glideslope capture, which never happened since the actual altitude never got below the red glideslope dot.  So, my actions probably prevented the glideslope capture from happening.  However, I wasn't actually asking if I did the correct thing -- only what the correct procedure actually is.

So, if I understand What Pils said above, the procedure for an RNAV (RNP) approach is:

  1. Fly this procedure with FMS1 or FMS2 selected as the navigation source.
  2. Before TOD, select altitude setting to glideslope intercept altitude or altitude assigned by ATC, since this acts as a constraint on descent,
  3. Press VNAV to engage VNAV mode
  4. Optionally, press VS and set a descent rate.  VNAV mode will respect the altitude constraints (and optionally speed settings) in the flight plan.  Probably not needed.
  5. Before the glideslope intercept, press APPR to arm VGP, the synthetic (computed) glideslope or glidepath.
  6. When the glideslope is intercepted, VGP will activate and the aircraft will descend along that path.  Once VGP activates, the altitude constraint indicated by the selected altitude will be ignored.

Cheers and thanks for the feedback.  I will try this procedure now and see how well it works.

Edited by cwjohan
  • Like 1
Link to comment
Share on other sites

On 3/22/2022 at 5:40 AM, JJM said:

Just to clarify, it's an RNAV (RNP) The only other approach type available for PSP 31L is a VOR approach. Go to DEP/ARR to select the approach. What altitude did you originally have set, and did you arm the approach?

I guess it's a VOR approach because HIXOV is PSP104/10.2 and TEVUC is TRM272/10.7.  I hadn't noticed that on the approach chart.

Link to comment
Share on other sites

54 minutes ago, cwjohan said:

One thing I unsure of is whether step 3 is optional -- that is, whether the descent will happen without pressing VS and setting a descent rate.

If you do nothing then you’ll descend in VPATH similar to a Garmin navigator. However if you want to use VVS or VFLC that’ll work too. VPATH would be SOP as far as I know.

Edited by Pils
  • Upvote 1
Link to comment
Share on other sites

39 minutes ago, cwjohan said:

I guess it's a VOR approach because HIXOV is PSP104/10.2 and TEVUC is TRM272/10.7.  I hadn't noticed that on the approach chart.

VOR or NDB approaches can be flown with the same procedure. It’s fancy!

  • Upvote 1
Link to comment
Share on other sites

I tested the above procedure today (without invoking VS or setting descent rate) and it worked fine.  I waited until the glideslope intercept altituded was reached before pressing APPR.

Link to comment
Share on other sites

I'm going to put in my two cents worth, and my procedure will differ somewhat from what the "schoolhouse" teaches. 

Let's talk about the easiest scenario, which is an RNAV (GPS) or RNP approach to LPV or LNAV/VNAV line of minima. The minima for these approaches are specified as a decision altitude or DA.  They provide the same TERPS or PANS-OPS protection for a momentary descent below the DA as does an ILS approach.  From the initial approach fix (IAF) inbound, you should have VNAV selected.  You may use VVS, VFLC, or VPTH to descend the aircraft through the initial and intermediate segment step down fix altitudes, and VNAV will honor all of them.  However, the easiest is to fly VPTH and let the VNAV track the vertical path through each of the stepdown fix altitudes to the final approach fix crossing altitude.  You may select the APP button at any time after the final approach fix.  Once selected, the Vertical Glidepath (VGP) mode will be armed (shown as a white VGP in the FMA) and will become the active mode during the in the intermediate segment sometime past the (IF) fix. There are two important things about the VGP mode:

1.  It will not honor the altitude preselector set altitude.  If you're not cleared for the approach, if VGP has captured, it will descend on the final past the FAF.   Once VGP is annunciated in Green, you can set the missed approach altitude just like on an ILS 

2. On very hot days, e.g., 40C plus, VGP may not honor intermediate segment stepdown altitudes.  The reason for this is that VGP mode from the IF fix inbound uses SBAS to compute the vertical path, which is not affected by non-standard temperatures, and like an ILS glideslope will take you below the intermediate segment stepdown altitudes on a very hot day.  So, on a very hot day, you might want to stay in VPTH mode until passing the last stepdown fix in the intermediate segment, then press the APP mode.  You might have to use VS to vertical speed down to capture the VGP path from above. I do not know if X-Plane or Hotstart models this behavior, but this is something to watch out for in the real Collins SBAS equipped airplanes. 

Past the FAF, you would descend to DA in VGP mode and at DA, if the runway is not in sight, press the go-around mode and then climb out and execute the missed approach. 

On an approach with the LNAV/VNAV line of minima, the procedure is the same; however, VGP vertical guidance is based on Baro-VNAV.  You must honor the low and high temperature limits published on the approach, but you don't have to worry about the VGP path going below the published intermediate segment stepdown altitudes. 

An RNAV (RNP) AR or RNP AR approach is pretty much the same thing. However, I am not sure if the Collins system uses SBAS guidance for the vertical in the final approach or if it is using just LNAV/VNAV.  RNP AR approaches are a strange breed because use a "Vertical Error Budget" or VEB for vertical obstacle clearance, which was originally based on Baro-VNAV use.  I actually believe it does use SBAS guidance inside the FAF/FAP, but I need to check on that. 

The next scenario is if you are flying an RNAV (GPS), RNP approach, or a conventional approach (VOR or NDB) using the FMS.  The minimums are all based on a minimum descent altitude or MDA, which is a hard altitude that you cannot go below during the approach without the runway environment in sight.  For an RNAV (GPS) or RNP approach (not RNP AR...easy to get confused since ICAO has muddled the terminology), you would fly the approach to the final approach fix (FAF) described as above except that you would remain in NAV (LNV) and VNAV (VPTH) mode. Approaching the final approach fix, you would set the altitude preselector to the MDA.  In the CL300/350 PL21, when you dial the altitude preselector down by 1000' increments, it will have an increment that matches the BARO setting on the PFD.  I don't know if the CL650 has the same feature, but suspect that it does.  In VPTH mode, the aircraft will level at MDA that is set in the altitude preselector.  However, there's a problem...

If you are descending on the VNAV path in VPTH from the FAF to the runway threshold crossing height, if you level even for a moment at the MDA, you are now above path. if you suddenly see the runway, there is an urge to "go for it", and that's how runway excursions and landing overrun accidents occur.  With the constant descent final approach (CDFA) concept, you never level off at MDA.  Further, you add a height adjustment to the published MDA to account for the transition from CDFA or VPTH descent to the missed approach climb.  In some European States, that height additive is specified by type in the AIP (e.g., France).  In other States, it's left to the operator.   If you have to determine one, a good rule of thumb is the USAF's 10% of the vertical speed anticipated on final, which is shown on the Jepp charts for the goundspeed expected in the final segment. For 3.0 path, that will be about 60 feet for most CAT C aircraft.  A descent path more than 3 degrees may require a larger additive.   If you don't apply CDFA in Europe, the approach minimums are increase by a meter equivalent of approximately 1/4 SM for CAT C and CAT D aircraft so that you will see the runway before you get to the nominal 3.0 descent path to the runway. That way, they ensure that you see the runway before the nominal 3.0 degree descent point.   No such rule in the US where CDA is encouraged, but it is voluntary. 

Most schoolhouses teach setting the altitude preselector to MDA (with or with additive) when either on VPTH or level in ALT with VPTH armed when approaching the FAF, then using NAV (LNV) and VNAV (VPTH) to descend and level at MDA.  My preference is to fly it like an RNAV (GPS) approach with LPV or LNAV/VNAV minima or an ILS approach.  I set the BARO to the MDA plus the additive and then use VGP mode since I'm never going to level at the MDA+additive.  When the voice says "minimums, minimums", if the runway is not in sight, it's a missed approach just like LPV, LNAV/VNAV, or ILS approach.   This falls into "technique", but it does drive some instructors nuts because they want to show me the system. I want to show them how I'm going to fly the airplane!

A VOR or NDB approach is similar; however, the FMS will warn you that it is a REF APPR only, meaning that from the FAF to the missed approach point (MAP), you must have a VOR needle or CDI or at the NDB/ADF needle displayed and that it must also be used for primary course guidance in the final segment.  Otherwise, the procedures described above are the same. 

I don't know if this answered your question, but I hope it helps.

Rich Boll

 

 

 

 

 

 

  • Like 5
Link to comment
Share on other sites

On 3/28/2022 at 11:30 PM, richjb said:

Most schoolhouses teach setting the altitude preselector to MDA (with or with additive) when either on VPTH or level in ALT with VPTH armed when approaching the FAF, then using NAV (LNV) and VNAV (VPTH) to descend and level at MDA.  My preference is to fly it like an RNAV (GPS) approach with LPV or LNAV/VNAV minima or an ILS approach. 

Yep I believe most school house want *first* to emphasize to young pilots the conceptual difference between non precision approaches (2D Apps) and precision approaches, where for ages everybody did the same way, ie dive to the MDA and maintain it until the missed approach point. The schools don't want pilots to confuse between approach types and may teach [the traditional] different techniques to make the pilot behavior help differentiate APPs types. I would bet it's a pedagogical approach rather than a complete course an all the developing stories on how to fly an approach with CDFA to MDA + addendum.

Then later in the airlines, and depending on SOP and budget, the CDFA may be seen as a supplementary technique to teach in order to bring commonalty of operation for all approach types, but the aware pilot still is able to discern between the various approach categories.

On 3/28/2022 at 11:30 PM, richjb said:

This falls into "technique", but it does drive some instructors nuts because they want to show me the system

Maybe just reassure them that you have perfectly understood the underlayin concept... and nevertheless will apply CDFA techniques.

Also, in accordance with the evolution of flying techniques, private providers and State chart depictions may differ for the same approaches.

1985696943_Capturedu2022-03-3010-36-28.png.db559994d937ea0a6cd1a376b58f116a.png739619162_Capturedu2022-03-3010-36-53.thumb.png.74afc0f06d760d102fc157347bd217c9.png

 

 

Approach_minimums_LIDO_Jeppesen.pdf

  • Like 3
Link to comment
Share on other sites

13 hours ago, XPJavelin said:

Yep I believe most school house want *first* to emphasize to young pilots the conceptual difference between non precision approaches (2D Apps) and precision approaches, where for ages everybody did the same way, ie dive to the MDA and maintain it until the missed approach point. The schools don't want pilots to confuse between approach types and may teach [the traditional] different techniques to make the pilot behavior help differentiate APPs types. I would bet it's a pedagogical approach rather than a complete course an all the developing stories on how to fly an approach with CDFA to MDA + addendum.

Then later in the airlines, and depending on SOP and budget, the CDFA may be seen as a supplementary technique to teach in order to bring commonalty of operation for all approach types, but the aware pilot still is able to discern between the various approach categories.

Maybe just reassure them that you have perfectly understood the underlayin concept... and nevertheless will apply CDFA techniques.

Also, in accordance with the evolution of flying techniques, private providers and State chart depictions may differ for the same approaches.

1985696943_Capturedu2022-03-3010-36-28.png.db559994d937ea0a6cd1a376b58f116a.png739619162_Capturedu2022-03-3010-36-53.thumb.png.74afc0f06d760d102fc157347bd217c9.png

 

 

Approach_minimums_LIDO_Jeppesen.pdf 4.24 MB · 2 downloads

Jeppesen began publishing the "DA/MDA (H)" several years ago when ICAO and EASA adopted the "Aerodrome Operating Minima" concept, which you see by the "Standard" annotation in the upper left corner (cut off here in this graphic") is applied to this procedure. It is one of the approaches where the pilot, if they do not have use CDFA techniques, they must add visibility penalty to the approach's minima, which also affects the approach ban.  

The attached Jeppesen Briefing Bulletin from 2015 was written by Ted Thompson, Jeppesen's former Direct of Standards and Corporate Technical Lead. I worked with Ted a number of years in various FAA and industry groups.  Ted was able to explain how Jeppesen came to charting the DA/MDA minima on their charts. 

Rich 

 

Briefing_Bulletin_JEP_15A_Aerodrome_Operating_Minimums_Web_Version.pdf

  • Like 2
  • Upvote 1
Link to comment
Share on other sites

Quote

 

Thanks for your precisions, I did source this briefing  when I made my empirical review of minimum depiction above. It was intended as no more of a parenthesis in this topic and didn't intended to elaborate very more...

  The change was documented indeed. Nevertheless in between, Jeppesen had a confusing move by charting DA/H on NPAs that people knew for years charted with MDA/H. The mention CDFA is now more clear, when accompanied by the read of the 2015 bulletin. But take a look at LGSA 13-3 chart. It was only in June 2021 than the AOM conversion with appearance of the CDFA text happened, it stayed with the sole half-baked "DA" for years, explaining why I've read confusion on the the internet for such a VOR app.

On 3/31/2022 at 12:26 AM, richjb said:

if they do not have use CDFA techniques, they must add visibility penalty to the approach's minima

Here I'm listening... I didn't catch that before. "They" ? Who ? Pilots ?

If I take LGSA VOR approach, it's not intended for CDFA in the State AIP (which pictures a dive and drive profiles and an OCA/OCH), so I would either

Fly this CDFA with MDA1310+addendum 50= Derived DA 1360. (In the Challenger with the FMS Derived vertical path that would be my natural choice after careful check of the angle encoding).

Or fly this the old fashioned way (but nevertheless legal) dive and drive to the MDA 1310 feet (= State OCA if no further limiting parameter apply from my aircraft or airline), Vis2400m. I don't see where I would apply a penalty anywhere here as pilot ? Or maybe the 2400 meters seen here are exactly the application of the Standard AOM (as they don't show up on the State chart), and that may be what you call a penalty ? (I will continue reading here https://ww2.jeppesen.com/publications/ to check that myself and learn)

From the 2015 briefing I can read

...State-published visibilities and, if necessary, compare them to the ICAO-based values. When available, State AOM will always be depicted. State AOM may be supplemented with higher ICAO AOM values and noted accordingly.

So the only visibility penalty that I understand here is when Jeppesen draws a chart, it can write a bigger visibility minimum (from ICAO guidance, as "standard" moved from ECOMS to ICAO AWOM) than what is published by the State.

Caution : that has changed between 2015 and the new Jeppesen briefing of 2019 !

Quote

State-provided AOM will always be depicted as published by the State. State-provided visibilities may be lower than the visibilities determined according to ICAO’sAWOM. The determination of lower values by the State is not precluded by ICAO if such values result in an acceptable level of safety. Therefore,the State-provided visibilities will not being raised to match the visibilities from the tables in ICAO AWOM. If the State does not provide AOMfor “ALS out” condition, ALS out visibility values will be determined according to the rules and tables in ICAO’sAWOM, butnot belowany State-provided visibilities for operational approach lights. “Provided by State” means either,minimum visibilities are published on procedure source,within the Aeronautical Information Publication (AIP), or aspecific AOMconcept has to be applied within this State.
b. Where aState does not provide anyAOM, Jeppesen will determine visibility values according to the rules and tables in ICAO’sAWOM.

That 2019 new policy explains in my view what I see on the LGSA 13-3 chart : not "standard" but "Std/State".

Jeppesen is really playing the valse since the 2000s, changing their charting.

 

Briefing-Bulletin-JEP-15-A-Announcement-AOM-Concept-23-AUG-19 (1) (1).pdf

Edited by XPJavelin
  • Upvote 1
Link to comment
Share on other sites

I have never really bothered about Jeppesen "standard" as I don't use this provider usually but now that I am lead to dig info about it, I am learning things.... Those 2400 and 3600 meters in the circling minimums boxes are indeed not from the State but applied by Jeppesen (and Lido) from the AMC7 CAT.OP.MPA.110Table 7 of the Jeppesen paper about -EASA AIR OPERATIONS (~ ICAO AWOM). 

I have seen also a reference to a penalty. U.S. OPSPEC requirement for non-CDFA penalty applies of the jepp charts provided are based on TERPS, but that very US I guess, as a European simmer, I would need to dig more to learn what is TERPS, but chances this is becoming outdated and not very required, as we transition to the ICAO AWOM world wide at Jeppesen, and this is the flavor we get with Navigraph.

Edition : also on the aesa doc for a VOR app I can see some non CDFA penalty, the max RVR is According to AMC5 CAT.OP.MPA.110 Table 5 if flown using theCDFA technique, otherwise an add-on of 200m for categoryA andB aeroplanesand 400m forcategoryC andD aeroplanesapplies to thevalues in AMC5 CAT.OP.MPA.110 Table 5 but not to result in avalue exceeding5000m.

But this not applies to LGSA VOR Y 29 which is my template study here, here I understand AMC5 CAT.OP.MPA.110 Table 6.ACAT I, APV,NPA
Minimum and Maximum applicable RVR
 applies to provide the maximum RVR of 1500m/2400m charted by Jeppesen (and Lido for cat C and D acft). (Edition : The TERPS table does not cut the maximum RVR at 1500m/2400m, an equivalent of this table 6 does not exists for the FAA)

So I can confirm, with standard ops, no  eed to worry about non CDFA penalty I guess, I can fly dive and drive or CDFA to the same numbers (and the private provider like Jeppesen can draw the same chart and mins being valid for both techniques). In AESA ops, penalty does exist, but only for approach not fulfilling the criteria in AMC4 CAT.OP.MPA.110 a.1.(ii). (Ie, more than. 3.77 angle for cat C and D, final track of the approach more than 15° off runway track....)

I interpret better now what you meant by the term "penalty". Politically speaking, I interpret (from the Jeppesen publication about AESA ops) the fact that more thrust is placed in CDFA technique for those last approaches than the old school dive and drive which get a visibility penalty.

Now if you don't have a private company like Jeppesen that did all the calculation in application of those pages and pages of tables, and you use the State charts (without RVR, visibility minimum like at LGSA) I would be bothered to do all the digging and calculation myself in the cockpit. I now some pilots fly only with the State charts, and this is legal and even the only legal source, but then, if you don't pay attention, you could fly an approach not complying to AMC4 CAT.OP.MPA.110 a.1.(ii) with less than legal RVR without realizing it.... Isn't it ?

I have checked on my LIDO manual (from 2013!) And they say their minima are AESA ops based. (Similar to ICAOM AWOM except that in this later, the concept of visibility penalty for a niche of NPA approaches has not be retained). I wasn't able to find a more recent lido chart legend manual.

Edited by XPJavelin
  • Upvote 1
Link to comment
Share on other sites

Hi Javelin,

Excellent research.  The August 2019 Jeppesen Briefing Bulletin is attached below for the benefit of others. Pardon the extensive highlighting.  Bad habit of mine. 

Here's my take on it.  Referring to the following document: Annex to ED Decision 2012/018/R:

AMC4 CAT.OP.MPA.110 Aerodrome operating minima CRITERIA FOR ESTABLISHING RVR/CMV

(a) Aeroplanes

The following criteria for establishing RVR/CMV should apply:

(1) In order to qualify for the lowest allowable values of RVR/CMV specified in Table 6.A the instrument approach should meet at least the following facility specifications and associated conditions:

(i) Instrument approaches with designated vertical profile up to and including 4.5° for category A and B aeroplanes, or 3.77° for category C and D aeroplanes where the facilities are:

(A) ILS / microwave landing system (MLS) / GBAS landing system (GLS) / precision approach radar (PAR); or

(B) APV; and where the final approach track is offset by not more than 15° for category A and B aeroplanes or by not more than 5° for category C and D aeroplanes.

(ii) Instrument approach operations flown using the CDFA technique with a nominal vertical profile, up to and including 4.5° for category A and B aeroplanes, or 3.77° for category C and D aeroplanes, where the facilities are NDB, NDB/DME, VOR, VOR/DME, LOC, LOC/DME, VDF, SRA or GNSS/LNAV, with a final approach segment of at least 3 NM, which also fulfil the following criteria:

(A) the final approach track is offset by not more than 15° for category A and B aeroplanes or by not more than 5° for category C and D aeroplanes;

(B) the final approach fix (FAF) or another appropriate fix where descent is initiated is available, or distance to threshold (THR) is available by flight management system / GNSS (FMS/GNSS) or DME; and

(C) if the missed approach point (MAPt) is determined by timing, the distance from FAF or another appropriate fix to THR is ≤ 8 NM. (iii) Instrument approaches where the facilities are NDB, NDB/DME, VOR, VOR/DME, LOC, LOC/DME, VDF, SRA or GNSS/LNAV, not fulfilling the criteria in (a)(1)(ii), or with an MDH ≥ 1 200 ft

 

To use Table 6A, for a NPA approach CDFA techniques must be used.  Table 6A is attached below. 

From Table 6A at the bottom:

For NDB, NDB/DME, VOR, VOR/DME, LOC, LOC/DME, VDF, SRA, GNSS/LNAV: - not fulfilling the criteria in in AMC4 CAT.OP.MPA.110, (a)(1)(ii), or - with a DH or MDH ≥1 200 ft Min 1 000 1 000 1 200 1 200 Max According to Table 5 if flown using the CDFA technique, otherwise an add-on of 200 m for Category A and B aeroplanes and 400 m for Category C and D aeroplanes applies to the values in Table 5 but not to result in a value exceeding 5 000 m.

Since paragraph (a)(1)(ii) states "Instrument approach operations flown using the CDFA technique", if you do not use CDFA technique even on these approaches where the vertical path falls within the maximum values specified, there is a 200 m (CAT A & B ) or 400 m (CAT C & D) applied.  

I can see where it might be interpreted the other way as well. That's what makes this so dang confusing.  When I see CDFA on the approach, I interpret that to mean that I need to use CDFA on that approach.  As US based operator, we do not use the State charts or the AIP.  We rely on Jeppesen to figure this out for us, which is the value added service of using a provider like Jeppesen or LIDO. They provide standardized format regardless of where you fly in the world. 

 

To be honest, the who concept of AOM has been confusing as hell to US operators.  We don't have to worry about this in the US because US TERPS defines the visibility minimums for every approach based on runway/approach lighting, obstructions in the visual segment, the published MDA or DA, etc.  They apply to all operators.  That said, back in 2010 or so, there was a change in US TERPS to allow the promulgation of visibility minima in 1/8 SM increments specifically to support the ICAO SARPS and EASA rules supporting CDFA.  A European operator flying a US non-precision approach to a MDA and not using CDRA would have to increase the published landing minima for the approach by 1/8 SM for CAT A and CAT B aircraft, and by 1/4 SM for CAT C and CAT D aircraft.  That's why we see approaches in the US with strange visibility minima like 7/8 SM or 1 3/8 SM.  We never used to do that.  

Because US operators had to apply CDFA in Europe and other ICAO States that adopted the Annex 6 SARP, the FAA published AC 120-108 providing operator guidance on the application of CDFA.  CDFA can be used voluntarily in the US.  It's not required.  

You've piqued my curiosity.  I may need to do further research.  It's been a while since I have looked at the EASA operating rules. 

Thanks,

Rich 

1 hour ago, XPJavelin said:

app

 

Table 6A.JPG

Briefing-Bulletin-JEP-15-A-Announcement-AOM-Concept-23-AUG-19 (002).pdf AC 120-108 Continuous Descent Final Approach.pdf 1065467017_AnnextoEDDecision2012-018-R.pdf

  • Upvote 1
Link to comment
Share on other sites

Rich, YOU picked my curiosity and I spent the whole afternoon researching and learning. I now want to write my new or updated simplified guide to minimums for the simmmer, because I m sure many use those without realizing the backoffice. 

29 minutes ago, richjb said:

by 1/8 SM for CAT A and CAT B aircraft, and by 1/4 SM for CAT C and CAT D aircraft.  That's why we see approaches in the US with strange visibility minima like 7/8 SM or 1 3/8 S

Gives me headache, not used to imperial units, looks like ancient Greek to me. (Actually I can better read ancient Greek that this stuff). I would hate to be the european transatlantic pilot doing commuts with the US......

Thing is, as a PilotEdge simmer, I'll come across that for sure...

Edited by XPJavelin
  • Like 1
Link to comment
Share on other sites

1 hour ago, richjb said:

As US based operator, we do not use the State charts or the AIP.  We rely on Jeppesen to figure this out for us, which is the value added service of using a provider like Jeppesen or LIDO. They provide standardized format regardless of where you fly in the world. 

And also carry errors or "interpretations".

I have seen military guys saying they purposely avoid in the Air Force private providers and exclusively use  State Aip worldwide. So.... 

I'd would be an airline manager,  I'd use LIDO, far more clearer an constant presentation over the years.... ... than jeppesen....  At EDDF ILS z 07L, jeppesen makes no mention of the LTS cat 1 minimums as described in icao doc 9365.... Lido does. Same for lfpg ils 27L. However, I like the recent evolutions at jeppesen, effective 2020, were the mention "vnav DA instead of MDA is operator dependent" now explicitely appears on revised CDFA 2D approach charts. It required at least5 years of charting wigwags at jepp, but at least now itsbetter.

Screenshot_20220403-174307_X-plore.thumb.jpg.4dbe65777580cc17f195e209452852db.jpg

A last thing about LIDO, I said it was based on AESA, it's true but in fact two flavor are available, AESA OPS worldwide, or US customers flavor, which has TERPS within Canada and USA territories.

Since I see TERPS minimums in Aerosoft Lido KBOI charts for instance, I conclude that Aerosoft is distributing the second option...

Which is not bad, to have FAA rules in FAA land.

I'd be curious if a more recent documentation of Lido still references AESA OPS or doc 9365...

Edited by XPJavelin
  • Like 1
Link to comment
Share on other sites

4 hours ago, XPJavelin said:

Rich, YOU picked my curiosity and I spent the whole afternoon researching and learning. I now want to write my new or updated simplified guide to minimums for the simmmer, because I m sure many use those without realizing the backoffice. 

Gives me headache, not used to imperial units, looks like ancient Greek to me. (Actually I can better read ancient Greek that this stuff). I would hate to be the european transatlantic pilot doing commuts with the US......

Thing is, as a PilotEdge simmer, I'll come across that for sure...

Hi XPJavelin,

There is an RVR equivalent to the 1/8 and 1/4 mile as well.  Many airports in the US do not have RVR, so we're more dependent on prevailing visibility as opposed to runway visibility. We still do things in imperial units, through.  Feet instead of meters. 

It is one of the things we have get used to crossing the pond or flying down into the Caribbean where some islands follow the EASA PANS-OPS rules!

Rich 

 

 

 

Link to comment
Share on other sites

4 hours ago, XPJavelin said:

And also carry errors or "interpretations".

I have seen military guys saying they purposely avoid in the Air Force private providers and exclusively use  State Aip worldwide. So.... 

I'd would be an airline manager,  I'd use LIDO, far more clearer an constant presentation over the years.... ... than jeppesen....  At EDDF ILS z 07L, jeppesen makes no mention of the LTS cat 1 minimums as described in icao doc 9365.... Lido does. Same for lfpg ils 27L. However, I like the recent evolutions at jeppesen, effective 2020, were the mention "vnav DA instead of MDA is operator dependent" now explicitely appears on revised CDFA 2D approach charts. It required at least5 years of charting wigwags at jepp, but at least now itsbetter.

Screenshot_20220403-174307_X-plore.thumb.jpg.4dbe65777580cc17f195e209452852db.jpg

A last thing about LIDO, I said it was based on AESA, it's true but in fact two flavor are available, AESA OPS worldwide, or US customers flavor, which has TERPS within Canada and USA territories.

Since I see TERPS minimums in Aerosoft Lido KBOI charts for instance, I conclude that Aerosoft is distributing the second option...

Which is not bad, to have FAA rules in FAA land.

I'd be curious if a more recent documentation of Lido still references AESA OPS or doc 9365...

 In fairness, I've seen error with interpretation and application with both providers.   I work with both Jeppesen and Lido representatives in my day job.  Don't get me wrong, they both do a good job of presenting aeronautical data.  Lido has done some really good work with their charts.  The ground movement charts are some the best. 

They are still reliant on State AIP information, which can be difficult to interpret and sometime can be in error. 

When flying internationally, it is something that bears watching!

Rich

Link to comment
Share on other sites

5 hours ago, richjb said:

When I see CDFA on the approach, I interpret that to mean that I need to use CDFA on that approach. 

I understand better what you say here, after some thinking,  provided Jeppesen applies state minimums in priority,  which by the way are TERPS in you country. Otherwise, doing dive and drive you would apply a visibility penalty under TERPS rules.

Panops don't. Earlier today I concluded easa don't also but I'm confused to ight by a jeppesen doc saying also with aesa the penalty for noon cdfa.

 

Link to comment
Share on other sites

Just now, XPJavelin said:

I understand better what you say here, after some thinking,  provided Jeppesen applies state minimums in priority,  which by the way are TERPS in you country. Otherwise, doing dive and drive you would apply a visibility penalty under TERPS rules.

Panops don't. Earlier today I concluded easa don't also but I'm confused to ight by a jeppesen doc saying also with aesa the penalty for noon cdfa.

 

In the US, the FAA does not apply any visibility penalties if the pilot/flight crew uses "dive and drive" verses CDFA.  It is the EASA-driven, State operating rules that require European operators to increase their visibility minima for an approach if they elect to not use CDFA and "dive and drive" instead.  There is some school of thought with the US and FAA that "dive and drive" is still appropriate for NPA.  I agree with that when circling is required.  However, for most NPA straight-in approaches with straight-in landing minima, CDFA is more appropriate. 

Rich

Link to comment
Share on other sites

3 minutes ago, XPJavelin said:

Sure, some State still retains old charting or procedure conception habits

Worse yet, they mix them.  Some states are using PANS-OPS for procedure development, but then not applying the requirements for those procedures during flight operations.   For example, PANS-OPS in some circumstances requires the use of an alignment hold to enter a procedure turn or teardrop course reversal.  There is one state in the western hemisphere that designs their approaches based on PANS-OPS with the alignment hold published, but when you say you're going to do it, it can throw ATC for loop because they are not expecting it. 

  • Upvote 1
Link to comment
Share on other sites

37 minutes ago, richjb said:

State operating rules that require European operators to increase their visibility minima for an approach if they elect to not use CDFA and "dive and drive" inste

Yes I was re re re reading the doc 9365. I don't believe it's the 200/400 addendum but the wave off of the 1500/2400m cutoff when no CDFA is applied.

Butthat not aesa doc, it's icao 9365... so why jeppesen publication in its system thesis table says 9365 does  ot requires a non cdfa penalty

142408300_Screenshot_20220403-220852_XodoDocs.thumb.jpg.59b1e60838fd6651cc472e1715bb8f9a.jpg

when I read 9365/6.5.22.. sure it's not the same penalty, but it is one I believe...

Now to the AESA part 

 

629303649_Screenshot_20220403-223111_OperaMini.thumb.jpg.bcd4515595c5c6a2fb3142824b153450.jpg

Indeed I add 200m or 400m depending of my category. 

No that's not quite I took hours to conclude earlier today :

8 hours ago, XPJavelin said:

So I can confirm, with standard ops, no  eed to worry about non CDFA penalty I guess, I can fly dive and drive or CDFA to the same numbers (and the private provider like Jeppesen can draw the same chart and mins being valid for both techniques). In AESA ops, penalty does exist, but only for approach not fulfilling the criteria in AMC4 CAT.OP.MPA.110 a.1.(ii). (Ie, more than. 3.77 angle for cat C and D, final track of the approach more than 15° off runway track....)

The more I work, the less the picture is clear...

Practically, if I fly the LGSA y 29 with dive and drive,

1232559335_Screenshot_20220403-223808_NDPCharts.thumb.jpg.a49fa4fe16f78a57959c4eeb64eff039.jpg

I use 2800 m rvr, not 2400 ? As charted ? Oww...

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...