Selected and managed approaches. Questions (airbus related)

[z.khalid]

Firstly, I read somewhere that doing "selected" precision approaches don't usually make sense to do, and they should and usually are managed, is this true?
If you are radar vectored until your interception of the localizer, you are turning(selecting) headings until you can ARM the "approach" and intercept both loc and g/s, is this not selected precision?

I assume you can only do a managed approach if you are cleared for the approach from the start.

Also, on non precision approaches.
I don't quiet understand the difference between selected and managed modes here.
I was reading how on a selected approach you will on FAF engage the trk/fpa and then put a 3 degree slope and decent to your MDA.
Quiet confusing to me.

Could someone please care to explain?

Thank you

[gblen]

Theres a bit of a mis understanding here.

Selected precision approach? As in get vectors to an ILS and fly the approach? Thats the normal situation. You can manage NAV to a waypoint on the extended center line, then arm the LOC and GS. Youll nav to the intercept point, then pick up loc. You can sort of call that Managed but its not really. Youre just in NAV to a waypoint instead of a vector.

Managed and non managed refers to non precision approaches. Ie NDB, LOC only RNAV and VOR. In this respect, doing them managed or selected is down the the SOPs of the company and what the crew decide on the day. Managed reduces workload. Selected is no harm as you need to be able to do them in case a managed mode fails for whatever reason. Theyre always flown with autopilot in or else youre into raw data.

Getting vectors to intercept an ILS which is autopilot flown is the norm.

Managed non precision is when the autopilot takes care of the lateral and vertal guidance. AP will keep you in the profile while you monitor the height checks and tracking.

Selected is when you decide the vertical with V/S or FPA. Lateral is controlled by Heading or Track. You will not stay on the profile and will constantly have to modify selections as you are only following a radial and are not locked on to anything.


In terms of what you said about only being able to do a managed approach only if youre cleared for an approach. Doesnt really make sense, ATC wont have a clue if youre managed or selected. Or care either. Once you are cleared for the APP you fly the approach in whatever way you had planned.

Think your understanding of what these modes mean is a bit off the mark or what is done day to day. Hope this helps

[CAT3C AUTOLAND]

Just to add a couple of points.

With single engine operations most Airbus models cannot do single engine fully managed approaches with the AP, so selected guidance must be used.

Selected is no harm as you need to be able to do them in case a managed mode fails for whatever reason. Theyre always flown with autopilot in or else youre into raw data.

This is not quite right. You can still fly a fully managed approach without the AP and the ATHR. The flight director will give the pilot the vertical and selected guidance required to fly the approach as long it is coded in the FMGC with FINAL APP mode engaged on the FMA.

Another thing to understand is that when the A/C is flying an ILS, with the flight director the aircraft is responding to signals from the LOC and G/S transmitters, i.e. raw data. With a fully managed approach, as long as you have an operative GPS, the ground NAV aid i.e. VOR does not need to be working, but as mentioned above the lateral and vertical coding in the FMGC must be correct.

[Bus Driver Man]

With single engine operations most Airbus models cannot do single engine fully managed approaches with the AP, so selected guidance must be used.

This has been recently changed in our FCOM. Except for older A320's, it is now allowed to fly managed non-precision with single engine.





z.khalid:
Selected Non-Precision: You operate the AP in TRACK and FPA. (You pull hdg/track and vs/fpa). You select whatever the airplane has to fly and you have to correct for any deviations.
Managed Non-Precision: You operate the AP in APPR NAV and FINAL mode. (You push the appr pb). The AP will follow the programmed lateral and vertical profile from the FMGS.


You can also fly a selected ILS approach, by selecting a TRACK and FPA to follow the ILS signal and correcting any deviation by adjusting track and fpa on the FCU.
Indeed, this doesn't make much sense as you can just press the APPR pb to intercept and follow LOC and G/S.
If I remember well, you have to fly a selected ILS if for some strange reason the AP doesn't intercept the ILS signal.
However, it makes much more sense to fly a manual approach in this case, instead of fiddling with the AP.


So if you are being vectored for an ILS appr, when cleared, just press appr pb to arm loc an g/s. The AP will then make the interception an follow the ILS.

[CAT3C AUTOLAND]

Bus Driver Man,

It is all dictated by the MSN, it has nothing to do with age.

[Bus Driver Man]

Indeed, it depends on the MSN.

Where I work, the A320's with lower MSN (so older A320's) are not certified for single engine managed non-prec, while the higher MSN's (newer A320's) are certified.
Hence my statement regarding age.

[PT6A]

I think it would be better to say age and or MOD status....

[titaniumwings]

Hi,

I seen a set of procedures which says that RNAV approach can only be conducted in managed mode if the missed approach point is inside the runway. Else it has to be in selected mode (vertical profile in vs or fpa)

However there is no such restriction for a VOR approach. Meaning the VOR approach can be conducted in managed mode regardless of the position of the missed approach point.

Does anyone have a similar set of procedures in their operations? Does anyone know the reason why for this requirement?

Thank you very much for your comments.

[Greenlights]

Firstly, I read somewhere that doing "selected" precision approaches don't usually make sense to do, and they should and usually are managed, is this true?
If you are radar vectored until your interception of the localizer, you are turning(selecting) headings until you can ARM the "approach" and intercept both loc and g/s, is this not selected precision?

I assume you can only do a managed approach if you are cleared for the approach from the start.


a bit a while I did not fly airbus yet, but from memory, to be simple :

managed : you let the a/c do. You "just" monitor.
selected : you are still master, you use the A/P but you are more active coz you decise your speed, your heading etc

Manage mode, it good to save fuel, but when I flew I did not use a lot...coz under radar vectoring you use mostly selected mode of course. Because you have to change speed, heading etc many times.

IN manage mode, the plane follows your FMGS ! You can not do an approach from the start as you said, under managed mode, if your approach is not in the FMGS.
IN Asia, many times we had to fly under selected mode even from the start of the approach.

Airbus philosophy is to use manage mode the most possible... for them, the pilot is out of the loop.

In reality, and where I was, we can not use it most of the time. Many things do not go like in a book. There are many unexpected things .

Even if you fly a 320 you have to create radials yourself...so....

[Amadis of Gaul]

Hi,

I seen a set of procedures which says that RNAV approach can only be conducted in managed mode if the missed approach point is inside the runway. Else it has to be in selected mode (vertical profile in vs or fpa)



You "seen a set of procedures"? Seen where?

[titaniumwings]

It is my company's SOP. Which I believe is adopted from the airbus. Nobody seems to know why is the restriction.

Does you company have a similar SOP? Anyone care to share their company's SOP? Anyone knows of the reason for this?

Thanks very much.

[titaniumwings]

As you have mentioned, most of the time for ILS approach it is basically 'selected'. The lateral tracking would be 'selected' heading to intercept loc. Vertical profile would be 'selected' altitude to intercept glideslope. At best the speed can be managed.

We are training for our RNAV approaches. It is best done managed.

But why can't we do managed when the missed approach point is positioned before the runway?

Anyone?

Thank you very much.

[titaniumwings]

This is with reference with my company's SOP which I believe is migrated from Airbus.

Anyone with similar or different SOP for comparison?

Thanks a lot.