A320 OEI Approach (Early Stabilzed)

[eiffel]

On the A320, what is the recommended technique, for an OEI early stabilised approach ? (VOR or RNAV with a level off segment)

During the final level off segment, would you be fully configured before your FDP (final descent point) ? (let's say using NAV/FPA)

What about if you're overweight after an immediate return OEI ? Would you keep CONF2 until you reach your FDP and then Gear Down, Flap3, Flap Full ?

(Where is it mentionned on the FCOM/FCTM ? )

Thanks

[Fursty Ferret]

Configure to conf 3 and gear down (if performance permits). You can either land in conf 3 or take flaps full once established on the final approach.

If you establish on the inbound course at conf 1 and S speed, then at TOD - 3nm take flaps 2 -> gear -> flaps 3, you’ll find yourself maintaining idle thrust or close to as you start the descent.

Or just fly it managed and do a normal decelerated approach.

Edit: this is covered in the FCTM and touched on in the QRH.

[PilotLZ]

There are two QRH procedures related to the matter. One is ONE ENGINE INOPERATIVE - CIRCLING APPROACH, the other one is ONE ENGINE INOPERATIVE - STRAIGHT-IN APPROACH. The first procedure has a table with the maximum weight for circling in config 3 with gear down. If you're above this weight, you need to delay gear extension and plan for a flap 3 landing. The second procedure prescribes a flap 3 landing if a level-off is expected on final.

Further on performance, go-around climb gradient needs to be checked from your performance calculation programme. That's not written up in any of the ECAM or QRH procedures, but is usually mentioned as a company policy in the OM-B. As for the landing distance, don't expect to find anything about an ordinary engine failure in the QRH in-flight performance section. I've seen people reach for the QRH in the sim with the good intention of calculating a dedicated landing distance with engine failure, only to find out that there are just two very specific scenarios covered in the engine section - REV UNLOCK with buffet and SHUTDOWN with ENG FIRE pushbutton pushed and ice accretion.

One final point worth mentioning is that on some old aircraft you cannot use FINAL APP with one engine out as the autopilot version is not certified for it. Whether that's the case with any of your fleet, check in the FCOM - Limitations - Automatic flight.

[eiffel]

Thank you.
Still a bit unsure about the "OEI Straight-In Approach" procedure in the QRH...
Let's say you have an Eng. Failure on T/O at 72t. You are coming back straight away for a VOR (2D) approach.

For overweight landing (QRH Overweight), you can (...and it is recommended at this weight) land with Flap Full. But as you have to "level off" at the platform for your 2D VOR App, the QRH (OEI straight in approach) tells you to land Flap 3....
Would you go gear down/Flap3 just before your Final Descent Point, then Flap Full in the descent after FDP?
How would you fly it?

[FlightDetent]

Keep looking and reading properly. That is the tough part.

FCOM ABN Straight-in:
If NO level off expected during final approach:"
- DELAY CONF FULL UNTIL ESTABLISHED ON FINAL DESCENT

The way we'd fly it is according to company manuals, and whatever is the preferred consensus of the instructor pool this month (not necessarily the same thing).

For discussion here and to learn, in order to avoid picking any unwanted habits or awkward convictions, it's best to restrict one's self to what does the OEM say in FCOM / FCTM.

[Rt Hon Jim Hacker MP]

Regardless of twin engine type, I would try to avoid flying level with the gear down and landing flaps. It requires a lot of thrust and trim changes, making it harder work than is really needed.

Not flown a three or four engine type, so can’t comment on those.

[MENELAUS]

The issues are not dissimilar; if only to make one’s life a bit easier, try and avoid a level segment with gear down and landing config.

[Check Airman]

eiffel

Not sure what's meant by a 2D approach, but it sounds like you're talking about some sort of dive and drive. Why not just fly it using a CDA?

My personal technique is to leave the gear and flap (3 or full) retracted until I'm on the final glidepath that I need.

[MENELAUS]

Think he’s referring to the new categorization of approaches. Ils etc considered 2Dimensional.
3D RNP AR / LPV SBAS etc.
Happy to stand corrected.
it should really make too much difference OEI although 3D approaches tend not to have level segments.

[goeasy]

Doesn’t logic say, that flying level s/e for more than a few seconds is best with less drag? (Vls relative)

Why rush to add more until final descent is starting?
The rules of physics are often more penalising than those in manuals!

[Check Airman]

Globocnik

It seems that 2D and 3D refer to approaches without and with vertical guidance.

https://www.icao.int/Meetings/PBN-Symposium/Presentations/Workshop%20B/1.%20Flight%20Operations%20Requirements%20Forum/F04%20-%20Miguel%20Marin/PBN%20Symposium%20-%20Flight%20Ops%20Workshop%20Approach%20Classification.pdf

Seems a CDA would be easier. The odd time I need to do a loc approach, that's my preferred technique.

[vilas]

Eiffel

Most VOR/NPA approaches have a level platform altitude. This segment you fly gear down and Flap3. And after leaving the FDP select full flaps. There's is no confusion. The restriction to land with Flap3 is not for level flight at platform but any level off below that as would be the case in dive and drive approach which I don't think exist any more.

[pineteam]

Unless doing deccelerated approach with the Final Approach Mode, any NPA we are required to be fully configured before the FDP. Horrible to hear the engines screaming and burning so much fuel but anyway. I wonder in the case of very heavy aircraft in a hot day with a sudden engine failure right at that moment if the aircraft would be able to maintain altitude.:*
I know it’s very unlikely and we should be level off less than a 1 min while fully configured but just wondering.

[compressor stall]

Check Airman

The terminology hasn't spread everywhere (yet) but to clarify CDA and 2D are not mutually exclusive.

Very simply:
A 3D approach is where you have vertical guidance to follow - eg a glideslope in the screen infront of you. Half scale deflection is your tolerance.

A VOR is 2D in that you still fly a Constant decent angle but the PIC needs to continuously check the distance to run vs the altitudes and adjust the rate of descent to ensure terrain clearance (as you always have).

@Pineteam - from Airbus it is a recommendation - not a requirement - to be fully configured before the FDP. Of course your company may say otherwise.

[FlightDetent]

Check Airman Used to be NPA and PA. The precision standing for "providing electronic vertical guidance", the only other option had been visual for long ages (as in PAPI, VASIS). The arrival of various add-ons able to provide vertical steering commands typically on some sort of RNAV kit changed the terminology landscape.

Hence the new labels, NPA - PA duo redressed to 2D and 3D.

3D now contains the old school ILS as well as the newish baro-APV which could not have fitted inside the previous designator's definition of "precision".

As a matter of fact, nothing has changed.

2D is the same as NPA = pilot needs to figure out the altitude profile by reading the chart but never relying on the FMS profile (you do the alt/dist checks)
3D is the same as PA = pilot will follow the displayed vertical guidance; after verifying system's accuracy on a certified installation.


My 2c? New name, same tricks, old dogs. PAs now a sub-set of 3D approaches. As pointed out, flying a profile without a level-off, by a personal choice or regulatory enforcement, does not really attach to this topic either way.

Bonus points for you researching what date the new 2D/3D naming convention became effective. :ok:

[FlightDetent]

No screens of the old gospel, this is the intermediate version:

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/601x303/snippet_old_de62c65243e7a15ec7f61dc9969e3a9022421351.png

and the new
https://cimg0.ibsrv.net/gimg/pprune.org-vbulletin/600x195/snippet_new_27589bacf6ff1f34385cf8ff320387f130dddda6.png

[FlightDetent]

https://cimg9.ibsrv.net/gimg/pprune.org-vbulletin/592x324/snippet_old_2__ea95356fb06caae8c1ff66ebc6801271df29d907.png

[Check Airman]

FlightDetent

Thx, but I wouldn’t call what I did “research”. I did manage to learn something new though, so there’s that.

[FlightDetent]

Lost in the translation, none assigned yet. :} About 2013.

For anyone still wondering, the full text of PANS-OPS ICAO Doc 8168 has some good didactic value. In the quote that follows, some dead wood was cut by yours truly. Prior to the introduction of PBN procedures, there was a simple relationship between instrument approach procedures and instrument approach operations: a) non-precision approach procedures (NPA) were published which were flown as a two-dimensional (2D) operation; and b) precision approach procedures (PA) were published which were flown as a three-dimensional (3D) operation.

With the introduction of a variety of PBN vertically guided approaches which are not precision approaches (for example, the APV baro-VNAV approach and satellite-based augmentation system (SBAS) APV-I approach) there is no longer a simple relationship between the approach procedure and the type of operation. From an operational perspective, the classification of different instrument approach procedures into precision, non-precision, etc., is no longer relevant. The important classification is whether the approach is operated as 2D or 3D.

There are two methods for flying instrument approach operations, 2D and 3D. In a 2D approach operation, only lateral guidance will be displayed to the pilot, for example, in the form of a very high-frequency omnidirectional radio range (VOR) needle or ILS lateral deviation scale. A 3D approach operation will also provide vertical guidance in the form of a vertical deviation scale. The nature of the instrument approach operation depends on both the instrument approach procedure and the technique used to fly the procedure.

The CDFA technique can support either 2D or 3D approach operations and is a method of flying a non-precision approach. There are two methods of flying the CDFA: a) using a manually calculated descent profile (rate/angle of descent); and b) using a descent profile calculated by the on-board equipment such as baro-VNAV or SBAS. Apologies for the thread creep. Once vilas reads the FCOM to someone, it is officially answered anyway. :D

[Check Airman]

I'm convinced vilas works at Airbus as either an attorney, or a translator, because there doesn't seem to be a word in the manuals that he hasn't read. :)

[Vaclav Winski]

Hi! Maybe that explains why VOR approach OEI may not performed like RNAV appr OEI - AP OFF/ FDs ON. in FINAL APP mode?
maybe I'm wrong?

[CMpilot1]

eiffel

Dive and drive technique and the level-off segment on reaching MDA associated with this technique doesn't exist anymore. Since the NPA are flown using CDFA technique there is no level off segment on reaching MDA. Hence you would fly gear down/flap 3 before your FDP, then flap full after FDP. However, you may notice that this technique doesn't strictly qualify as an "early stabilized approach".
Here is what the FCTM has to say about EARLY STABILIZED APPROACH : "Early stabilized approach refers to an approach where the aircraft reaches the FDP in the landing configuration at VAPP. This technique is recommended for NPA(LOC FPA, NAV FPA and TRK FPA)". By reading this line alone one would assume that the airplane should be in landing configuration and VAPP before reaching FDP regardless if OEI or not.

However the QRH ONE ENGINE INOPERATIVE-STRAIGHT-IN APPROACH checklist would call for delay config full until established on final descent if no level off expected during final approach. (Implying CDFA)

[galdian]

How about you discuss with the other pilot your thoughts about delaying gear/flaps etc?
Hopefully he'd agree - or maybe say "what about xxxx consideration...." and you might say "yeah, fair point".

When you both agree a course of action off you go. Simples! :ok:

The books - QRH/FCOMS etc - will give you great procedures but cannot cover everything, very occasionally you may have to size things up and be responsible for the decisions you make and the reasons.

Of course if you've an uncontrollable engine fire and the wing's about to fall off slightly greater immediacy of actions. ;)

Cheers