Role of "Minimums" in Autoland/LAND 3

[zachlog 18]

If the minimums are not set or not set properly (RA or BARO), will it cause the cancelation of "Autoland" and force a manual landing ? I understand that the "Minimums" callout will not be heard. Thanks,Zach

[badderjet 181]

As long as the minima are set up they should be heard. What I observe however, is very often after a go-around the callouts that were played on the first approach won't play on the second one. Not sure if they set some sort of "played" flag to the sounds, I don't know. The panel state files suggest something like that, but it's pure speculation on my part. Also, depending on how 'close' the minimum is to a 'usual' callout altitude (e. g. 100), the one might play but the other not. Other than that, it has nothing to do with autoland. Minima apply for every approach, no matter how they are performed (excluding CAT IIIB approaches without DH obviously) and you need to adhere to them no matter if you fly, the guy on the right seat or George.

[zachlog 18]

As long as the minima are set up they should be heard. What I observe however, is very often after a go-around the callouts that were played on the first approach won't play on the second one. Not sure if they set some sort of "played" flag to the sounds, I don't know. The panel state files suggest something like that, but it's pure speculation on my part. Also, depending on how 'close' the minimum is to a 'usual' callout altitude (e. g. 100), the one might play but the other not. Other than that, it has nothing to do with autoland. Minima apply for every approach, no matter how they are performed (excluding CAT IIIB approaches without DH obviously) and you need to adhere to them no matter if you fly, the guy on the right seat or George.

Etienne, Thanks for the reply. I understand the significance of "Minimums". The reason for my question was that I am still getting "No Autoland" so I am looking for candidate problem areas so I thought this might be one of them. Both radios tuned to the ILS Freq., Localizer, G/S, CMD B, Flaps at VREF, SPEED set to VREF+5....all are working fine except that right at the end, Autoland cuts out. There must be something I am missing. Thanks,Zach

[Petermuc3 8]

Zach,did you set both course selectors? Regards from EDDMPeter

[zachlog 18]

Zach,did you set both course selectors? Regards from EDDMPeter

Hmmm....I think I did but not 100% certain. I will retry and report back as soon as I have the opportunity. Thanks again,Zach

[badderjet 181]

Ahh, you were that, with the NO AUTOLAND issue. Forgot about that. Anything else, did you enable random failures? All failures checked and cleared? Everything set up, also on the overhead, electrical power distribution, both generators online? In case of fail-op equipment, ISFD aligned and operating? Two IRSs? No flags or other indications? Maybe you could post a large screenshot showing your entire panel when you get the message. Or maybe two more, of the overhead and the aft electronics panel too. Plus your location and intended runway of course. Maybe we can figure it out after all.

[zachlog 18]

Ahh, you were that, with the NO AUTOLAND issue. Forgot about that. Anything else, did you enable random failures? All failures checked and cleared? Everything set up, also on the overhead, electrical power distribution, both generators online? In case of fail-op equipment, ISFD aligned and operating? Two IRSs? No flags or other indications? Maybe you could post a large screenshot showing your entire panel when you get the message. Or maybe two more, of the overhead and the aft electronics panel too. Plus your location and intended runway of course. Maybe we can figure it out after all.

Etienne, When I confirm the setting of both CRSs (a couple of posts up), if I still get the "NO AUTOLAND", I will post a few screeshots. One question- Can you provide additional information on this one. >> ISFD aligned and operating? Thanks again,Zach

[bozflyer 5]

Etienne, Thanks for the reply. I understand the significance of "Minimums". The reason for my question was that I am still getting "No Autoland" so I am looking for candidate problem areas so I thought this might be one of them. Both radios tuned to the ILS Freq., Localizer, G/S, CMD B, Flaps at VREF, SPEED set to VREF+5....all are working fine except that right at the end, Autoland cuts out. There must be something I am missing. Thanks,Zach

I had same problem , i was used for my preference to change the "instrument transfer swithches" position. It MUST be all in CENTER position otherwise AIII do not arm.I was getting crazy but finally i coght the solution.Hope this help you.Paolo bozzetti

[badderjet 181]

When I confirm the setting of both CRSs (a couple of posts up), if I still get the "NO AUTOLAND", I will post a few screeshots. One question- Can you provide additional information on this one.

Probably bad wording on my part, but for fail-op operation you obviously need the ISFD to be working as your third "inertial source", although that's a bit of a joke, also the ISFD uses heading info from one of the IRSs so it's not truely a standalone source if you ask me. Anyways, if you simulated a failure of it and cleared the failure, it needs 90 seconds to align again. For a full fail-op landing it needs to be operational. If it's not working you should definitely see some sort of message, at least NO LAND 3. BTW Does anyone know what would be correct in the following scenario: Fail-op equipment, perform autoland. Anytime below 1500R, at least with LAND3 announced, fail the ISFD. NO LAND 3 appears on EICAS, other than that LAND3 remains enabled. Is this how it should be? Edited October 10, 2011 by badderjet

[zachlog 18]

I had same problem , i was used for my preference to change the "instrument transfer swithches" position. It MUST be all in CENTER position otherwise AIII do not arm. I was getting crazy but finally i coght the solution. Hope this help you. Paolo bozzetti

Paolo, Thanks for the suggestions but I don't know what this is referring to ==> "instrument transfer swithches" ? Zach

[badderjet 181]

They are on the overhead. If e. g. an IRS or DEU fails you can set all instruments on the remaining device, as usually for instance IRS L drives CM1's DUs while IRS R drives CM2's DUs.

[RYR738 9]

BTW Does anyone know what would be correct in the following scenario: Fail-op equipment, perform autoland. Anytime below 1500R, at least with LAND3 announced, fail the ISFD. NO LAND 3 appears on EICAS, other than that LAND3 remains enabled. Is this how it should be?

Just below 1500 ft and while the localizer and glideslope are flashing amber ( performing a self test )........If you RESET the ISFD at this exact moment you will see Land 2 announced instead of land 3.Land 2 still has rollout and flare and is a full autoland. Fred.

[badderjet 181]

Well, I know that. But I talked about what should happen if the ISFD fails after the self test, with LAND3 already announced. What it does on the NGX, as indicated above, is I get a NO LAND 3 annunciation, but other than that LAND3 stays enabled. I was wondering if a NO LAND 3 indication at that time would downgrade the active LAND3 to LAND2 for example, or if LAND3 is 'locked' by that time, apart from severe malfunctions obviously like an IRS failure or so.

[zachlog 18]

Ahh, you were that, with the NO AUTOLAND issue. Forgot about that. Anything else, did you enable random failures? All failures checked and cleared? Everything set up, also on the overhead, electrical power distribution, both generators online? In case of fail-op equipment, ISFD aligned and operating? Two IRSs? No flags or other indications? Maybe you could post a large screenshot showing your entire panel when you get the message. Or maybe two more, of the overhead and the aft electronics panel too. Plus your location and intended runway of course. Maybe we can figure it out after all.

Etienne, LAND 3 finally worked for me and apparently I was not doing anything incorrectly. I was practicing my landing skills over and over at KDTW Rwy 22R/ILS 111.95. There must be a problem with this rwy because when I switched to rwy 22L/ILS 110.7 next to it, and did not change anything else, LAND 3 worked like a charm. Thanks for all your feedback (and the rest of the people in this thread),Zach

[badderjet 181]

Yeah maybe something's wrong with the AFCAD here and there. Freqs tend to change every once in a while... maybe you might check the data for that particular runway.