about IAN(integrated approach navigation )system

[flying800]

:confused: hello all!
i'm learning about IAN approach,but only a little information for this ,anyone can give me some more detail of IAN? such as:IAN's background, merit and demerit，restiction,authorization of EURO or FAA etc. thanks !

[Flutter speed]

I assume you found this (http://www.boeing.com/commercial/aeromagazine/aero_22/737approach_story.html#3) link already?

Also, this (http://www.airbus.com/fileadmin/media_gallery/files/safety_library_items/AirbusSafetyLib_-FLT_OPS-GEN-SEQ02.pdf) pdf has a wealth of information.
If I remember correctly, IAN is a Boeing term, but the principles are applied by Airbus as well (something like FMC LOC and FMS G/S).

[Denti]

IAN is in my opinion just a simplification of procedures, instead of using different procedures for all kind of approaches one can use the same procedure for nearly every kind of approach. Instead of LNAV/VNAV or LOC/VNAV one simply uses the APProach mode same as on an ILS.

However there are still some differences, for example IAN does not allow dual channel approaches (quite correctly) and therefore has a green single channel indication instead of yellow, it creates an autocallout "AUTOPILOT" at 100ft RA to remind the pilots to take over manually and IAN cannot do RNP AR approaches. And of course one has to be careful which navaids are tuned since tuning an ILS can prevent IAN from doing its thing.

We use IAN since it was introduced by Boeing on the 737 and it is our standard procedure for non precision approaches, no idea if we needed another certification for it, however all crews received simulator training in its use, same as we did for CAT IIIb instead of CAT IIIa (both came for us at the same time).

[flying800]

：OK：thank you two guys .i'm a pilot of B787,and going to about IAN training,but IAN section is not detailed in B787's FCTM .speed's link is very useful. if possible , i want know more limitation and authorization . thanks!

[Intruder]

Denti:

Tuning an ILS does NOT "prevent IAN from doing its thing"! The I in IAN stands for "Integrated", and the system chooses the best available NAVAIDs for the approach. If an RNAV/GPS approach is loaded, and an ILS is available for the same runway, the system simply uses the LOC and G/S for guidance, once captured, since they are more accurate than LNAV and VNAV.

flying800:

Just think of IAN as integrating the Approach Mode into RNAV/GPS approaches in addition to ILS approaches.

Limitations and authorizations depend on the specific airline. In general, you can eventually expect the same RNAV approach to DH, and Cat II/Cat III authorizations the airline already has.

[Denti]

@Intruder, sadly if any ILS is tuned, even to another airports runway it will prevent the approach mode from activating the non precision approach, only exception of course is the LOC or ILS G/S out approach.

Common mistake is to never retune the NAVs and let them on the ILS of the departure airport and then being puzzled why the plane simply continues straight through the extended centreline without any interception. Not a big issue, one just has to be aware of it. Funny enough, never had that issue with a GBAS channel number, but it is much more rare to use those anyway.

[Intruder]

That should not happen if the ILS is left to auto-tuning. Once the approach is loaded via the DEP/ARR page, the ILS for that runway will be tuned, if available. There should be no conflicting ILS receivable in the terminal area.

Our procedures include deleting any manually tuned NavAids when climbing through 10,000'. If that is not a procedure at your airline, you may consider making it a personal one...

I have not tried manually tuning an invalid ILS before attempting an IAN approach, so I cannot confirm that it happens as you say. I HAVE loaded an RNAV approach and allowed it to automatically tune and capture the ILS for the same runway. Works fine.

[Fabo.sk]

I can imagine a situation when you are re-cleared from ILS to a non-prec approach that uses a different ground track, e.g. a VOR approach with VOR off the centerline. (sorry, can't remember how are those properly called).

Your airplane would not fly the VOR app track, but would try to intercept the ILS loc, even if you only planned to use that for reference. If the VOR approach is angled some 5° off the LOC, you can already run into quite a bit of distance error mid approach.

[Denti]

@Intruder, i was talking about the NG of course, the airplane where boeing introduced IAN. With autotuning on recently certified planes things may be different.

[Intruder]

The OP noted 787, which I assume is more similar to the 747-8 that I fly. I've never flown the NG; so I am not aware of its capabilities/limitations, and "of course" is not applicable...

When you're seeking/giving information, it's always a good idea to specify the airplane type, and specific avionics/engine where applicable...

[Intruder]

I can imagine a situation when you are re-cleared from ILS to a non-prec approach that uses a different ground track, e.g. a VOR approach with VOR off the centerline. (sorry, can't remember how are those properly called).

Your airplane would not fly the VOR app track, but would try to intercept the ILS loc, even if you only planned to use that for reference. If the VOR approach is angled some 5° off the LOC, you can already run into quite a bit of distance error mid approach.
In general, I don't know why you would fly a VOR approach if the ILS was operational. If for practice, Parking the ILS would be a good option.

The example I'm familiar with is Rwy 22L at JFK. The RNAV approach overlies the ILS localizer with a 225 course, but the VOR comes in at 232, crossing the extended centerline near the MAP. If the ILS (or G/S) was inop, the RNAV approach would be a better alternative than the VOR. However, I have gone into JFK when only the VOR approach was available, for whatever reason. It's been a while, but I suspect the ILS was out of service, so capturing the LOC would not be an issue.

[flying800]

fabo：

In B787 FMC always automatic tunes the VOR or ILS freq,once you re-choose a VOR insdead of ILS approach in DEP/ARR page . it will auto tune VOR freq ,and IAN also intercept VOR'S FAC.


Now, my question is :
1. Any limitations for GP angle？ as you know ILS is 2.5-3.25.
2. If in radar vector ,can i fly directly some waypoint after FAF,and if able,how and when does the RNP change into 0.3?
3. How to disengage IAN'S APP mode ? the same as ILS ?
4. Do i need go-around,if lost raw data in IAN app?
5. Can IAN do G/A with A/P? what's the differrent of IAN's manually G/A and autopilot G/A ? such as FMA's change.

By the way the NG what you said is B737-NG?

[Denti]

I'm sorry, I missed the 787 part and I'm probably a bit complacent as the 737 until last year was the only Boeing type in service that used IAN, therefore I went my merry way down the wrong path. Yes, with NG I do mean the 737 NG which served in the last 10 years as line-testbed for new flightdeck stuff now being rolled out on new types, like IAN, VSD or the ISFD.

But the 737 has some disadvantages, mainly because some big customers (for example a big US low cost company) wanted it that way to maintain communality with older variants, so there is no stuff like auto tuning or EICAS, although both are technically possible.

[Intruder]

Now, my question is :
1. Any limitations for GP angle？ as you know ILS is 2.5-3.25.
2. If in radar vector ,can i fly directly some waypoint after FAF,and if able,how and when does the RNP change into 0.3?
3. How to disengage IAN'S APP mode ? the same as ILS ?
4. Do i need go-around,if lost raw data in IAN app?
5. Can IAN do G/A with A/P? what's the differrent of IAN's manually G/A and autopilot G/A ? such as FMA's change.
Does your FCOM not have the information?

For the 747-8:

1. 2.75-3.77 deg.

2. No.

3. Yes.

4. What raw data? Look at the approach plate. If a VOR or LOC approach, or DME required, then yes if not visual. If an RNAV approach, then no.

5. Yes. AP/FD FMA will be LAND 3 or LAND 2 or NO AUTOLAND or CMD or FD, as appropriate.

[FlightPathOBN]

Denti,

Quite right about RNP AR...was validating a few procedures for CYLW in the full motion sim, and for the hell of it we tried out the IAN system....

good thing it was in the sim!

[flying800]

Intruder:
Thanks for your answer!

I'm just beginning to learn B787 FCOM and not familiar with this . by the way what section is this information in B747-8 FCOM?

For question 5, IAN cann't do autoland ,so PFD will not display land 3 or land 2.keep A/P displaying down to 100ra then changing to NO AUOTOLAND.

[FlightPathOBN]

at least with the 787, you will have quite a bit of time to study and learn before being able to fly one... :{

[Intruder]

For question 5, IAN cann't do autoland ,so PFD will not display land 3 or land 2.keep A/P displaying down to 100ra then changing to NO AUOTOLAND.
If the LOC and G/S are captured, even if the original approach setup was for a VOR or RNAV approach, then AUTOLAND 3/2 WILL be displayed! Remember what the "I" stands for!

Get familiar with the FCOM. Limitations, Normal Procedures, and Autoflight are good sections to start with for IAN...

[Intruder]

Which approach were you cleared for? Which did you brief?

YOU fly an approach, using the guidance given by NavAids and the FMS. YOU decide whether or not the guidance is valid for the approach YOU are flying.

In the 744 and 748 you can manually "Park" (disable) the ILS; but why would you want to, if it is giving valid guidance for the approach? Even without IAN, the 744 will tune and capture the ILS when an RNAV or VOR approach to the same runway is loaded. It's not a new concept...

I see the ILS X Rwy 12 mins at KEAT as 318/1, and the RNAV (RNP) Rwy 12 as 769 / 2-3/4...

What are you currently flying? IAN should not be that much of a mystery. It's merely a slightly more automated method of flying non-precision approaches.

[aterpster]

ok465:

edit: Does the air traffic approach clearance verbiage consist of "cleared for whatever approach the box decides to do"

which box, the FMS or the burning battery? :)

[whale2guppy]

my question is the use of IAN on an RNAV RNP approach with RF legs. Can you use IAN? My understanding is Boeing says it is not recommended in descending turns as the descent profile is not assured. Does anyone have any more information on this? Would appreciate any references

[Fursty Ferret]

If an RNAV/GPS approach is loaded, and an ILS is available for the same runway, the system simply uses the LOC and G/S for guidance, once captured, since they are more accurate than LNAV and VNAV.

Not convinced by this. Do you have an FCOM reference?

Common localiser frequencies for the reciprocal runway would cause an RNAV approach to end in tears.

[ScepticalOptomist]

whale2guppy

No, IAN is for straight in approaches. Think NDB/VOR or RNAV Z approaches. RNP with curved legs should be flown using LNAV / VNAV as per the FCOM.

[8che]

Fursty Ferret

Of course he doesn’t. It’s not possible to get a reference for that kind of rubbish​​​​​​…

[vilas]

IAN is a way of using FMS vertical glide path when ILS glide path is not available. Airbus has a similar system and calls it FLS or Flight management Landing System. It may be a VOR approach where vertical guidance is not coded in FMS, what's called managed in Airbus or using ILS localiser only approach because GS is not available. It cannot be that IAN will use ILS when you want to do a VOR approach. because which minima will you use. It helps flying a non precision approach ILS like with FD LOC and GS indications but from FMS. It cannot be used for RF leg approach.

[B777Heavy]

whale2guppy

No, IAN is for straight in approaches. Think NDB/VOR or RNAV Z approaches. RNP with curved legs should be flown using LNAV / VNAV as per the FCOM.


what is the definition of a “straight in approach”? I saw somewhere that this is around 3degrees of centerline. Is that correct? Does that mean you shouldn’t do an IAN on an OFFSET approach?