Airbus FLS Mode

[Capn Bloggs]

Airbus FLS mode has been mentioned in another thread. Could somebody explain what it is? :D

[maggot]

FMS generated loc and glide slope indications that respond like an ILS display to fly NPAs, whether rnav, NDB or vor etc

Edit: it's awesome :)

[Capn Bloggs]

Thanks Maggot, would I guess right FLS=FMS Landing System?

[maggot]

Yeah I think so. I've been off type for a little while now and too many TLAs!

[747-8driver]

Same as IAN on the B748 I suppose?

[maggot]

Well if you elaborated we'd know

[ACMS]

Capn Bloggs:

Try this link. Go directly to page 38 for FLS description.

http://www.dream-air.ru/new/pilotam/NON-PREC-APPR.pdf

[Capn Bloggs]

Thanks ACMS. Ironically, page 37 has a proof of the 13R RNP at JFK. D'oh!

[Denti]

Is that an user option? I was used to IAN on the 737 and found the managed approaches, especially the LOC approach, a step backwards on the minibus.

[infrequentflyer789]

Currently standard on A380 & A350, optional on others. Only available/certified for 320 since 2010 and there are some specific equipment requirements, so I imagine that operators with fleets that don't (all) meet the requirements will have choosen not to (retro)fit.

[Denti]

Thanks, hope an airline with a fairly new fleet will eventually use it.

[aterpster]

Thanks ACMS. Ironically, page 37 has a proof of the 13R RNP at JFK. D'oh!

Note the proof reader goofed. The inset labels the RWY 13R waypoint as 13L.

BTW, this RNP AR IAP does not meet FAA RNP AR criteria because the DA is in a turn (still in the last RF leg). Thus, it is a special only for those operators who have specific training in this procedure. At one time that was only Jet Blue. Don't know about today.

[Cough]

I think FLS is the GLS equivalent, not IAN...

[Denti]

Not according to the Link provided by ACMS above. GLS does not necessarily need a database coding as the approach geometry is transmitted on the selected channel and decoded and compared against the corrected GPS position in space in the MMR and the result shown as normal ILS position. FLS seems to use a FMS database coded procedure to construct an ILS lookalike lateral and vertical path. In that it is very much like IAN which uses a FMC database coded NPA for the same thing.

And of course GLS approaches are "just" normal precision approaches, albeit currently only approved to CAT I although they have been tested to CAT IIIb with very good results. Accordingly, autoland is possible from that. No idea if FLS allows autoland, boeing IAN, at least in the 737, on NPAs levels off at 100ft and an autocallout "AUTOPILOT" reminds one to disconnect the autopilot.

[maggot]

^^^ that's right. Disconnect at mins, it's still an NPA.

[maggot]

Is that an user option? I was used to IAN on the 737 and found the managed approaches, especially the LOC approach, a step backwards on the minibus.

Yeah the 'brick' is certainly retrograde! What is IAN?

[eckhard]

Integrated Approach Navigation. A way of flying an NPA with lateral and vertical guidance. Like FINAL APP in the Airbus.

Lateral mode is “FAC” (Final Approach Course);
Vertical mode is “GP” (Glide Path).

Provided that the final approach (from the FAF to the MAPt) is a straight line, we can use IAN by loading the approach from the FMC and using the “LOC/FAC” button on the MCP to capture the FAC, then the “APP” button to capture the GP.

The PFD/HUD displays pointers (triangles) to show FAC and GP deviations, like an ILS (which uses diamond-shaped deviation pointers).

For a LOC only approach, you can use “LOC” and “GP”, instead of “FAC” and “GP”.
In that case the lateral pointer will be a diamond and the vertical pointer will be a triangle.

[maggot]

Thanks
How does it display? Generated ILS like indicators, NPS, or?
The ILS like display on the 350/380 is what really makes it.

[eckhard]

ILS-like display, but little isosceles triangles (wedges) instead of diamonds.

[Denti]

In the 737NG i was flying there was actually no difference at all to the ILS display, same diamonds display. And the same behavior, the pointers became more sensitive the closer one was to the runway. The display was not dependent on the FD being on, so flying an approach manually without FD in a way similar to raw data based on the IAN pointers was possible. Only downside were the frequent GPWS „GLIDESLOPE“ callouts, as the computed vertical glide path is based on baro information it often was off on short final. Which shouldn’t matter as below DA one has to fly visually anyway, but the path is computed until 50 ft AGL and can trigger GPWS warnings. Only difference for LOC was the FMA, which showed LOC/GP instead of FAC/GP.

In my view therefore quite different to the old FINAL APP on the airbus, but probably very similar to FLS. Not to mention that FINAL APP is not available for LOC/BC approaches on the minibus.

Now, i stopped flying boeing three years ago, so there might have been changes in the meantime of course. Avionics wise the A320 was a step back in time, as an everyday office i prefer it.

[ACMS]

Maggot: How does it display? Look at page 38 of the document I hyperlinked above

[maggot]

Thanks, but I thought you were linking an airbus display. I was asking about the IAN. Answer received too thanks :)