4 minutes ago, aniiran said:

YES IT IS!  It did a perfect Autoland. I'm telling you its a PMDG problem. GO TO KSJC and try it for yourself or .... off

I couldn't tell you how many fail passive autolands I've done in the PMDG, and I can tell you it does work correctly.  You did not autoland out of that approach; the airplane flew itself into the ground.  I understand you saw the thrust reduce, as the autothrottles will always do that.  

I'll pick on PMDG for some things, but they've got this all exactly right.  Unless perhaps a bug has been introduced in the latest version that I've not used, but I doubt it.

Edit for clarity: "single channel" will never be an autoland.  If both autopilots were correctly engaged, your autopilot annunciation would be a green CMD instead of the amber Single channel, and you would also have a white flare annunciation under the active GS vertical mode, indicating flare is armed.

Edited February 11, 20251 yr by Stearmandriver

2 minutes ago, Stearmandriver said:

I've tested it enough to know how both systems work, using our level D sims at work.  Our fleet is configured with fail passive autoland and so that's what I fly in the real airplane, but I've also taught on the fleet and so I've explored options in the sim for my own enjoyment. 

Fail passive very definitely works correctly in the PMDG and does give you appropriate autoland annunciations (which are different from fail operational, but you do get a flare annunciation).  

That is not the premise of the thread.  This is specifically related to KSJC in MSFS not a real 737.  And yes here it is at KSFO performing in FAIL PASS.  It just doesn't work in KSJC.

 

10 minutes ago, anavsun said:

Thanks. For the FAIL OP option, what kind of failures will it detect?

Fail operational uses a third autopilot channel for yaw (and requires the ISFD standby instruments).  It provides rollout guidance after touchdown and so is another way to achieve lower landing minimums.  It's not typically used on fleets that have the HGS though as the rollout mode of the HGS gets you those same lower minimums and more versatility besides.  The name comes from the fact that if one autopilot channel fails, the system gracefully degrades into a 2 channel autoland approach (what you normally have in a fail passive system).  In other words, autoland remains operational if you experience a single failure.

None of this is relevant to making the plane autoland.  No need to worry about it for now.

6 minutes ago, aniiran said:

That is not the premise of the thread.  This is specifically related to KSJC in MSFS not a real 737.  And yes here it is at KSFO performing in FAIL PASS.  It just doesn't work in KSJC.

 

If one mode doesn't work in SJC, the other wouldn't either.  The only explanation (if fail operational worked) is that you had something set up incorrectly when you tried the fail passive.  Like I said, every FMA indication in your screenshot shows a single channel coupled approach.  You never had autoland armed at all for that one.  🤷‍♂️

9 minutes ago, Stearmandriver said:

autoland remains operational if you experience a single failure

Ok just so I understand. The main difference between Fail Op and Fail Pass is --in the former there is auto backup for auto-landing whereas in the latter there is no auto backup and therefore the latter requires pilot intervention (which I did not do in failed attempts at auto-landing).

1 minute ago, anavsun said:

Ok just so I understand. The main difference between Fail Op and Fail Pass is --in the former there is auto backup for auto-landing whereas in the latter there is no auto backup and therefore the latter requires pilot intervention (which I did not do in failed attempts at auto-landing).

Well... Kind of.  In fail op, if an autopilot fails you can continue the autoland (to slightly higher minimums).  In fail passive, if an autopilot fails you're back to a single channel approach and no autoland.

Neither system can "fix" things for you if you've got something wrong, nor will either system decide when to go around for you or anything.  They're just going to follow the beams to ground and apply some flare logic when they get there. 

Like I said above, there's no case where one would work and the other would not.

47 minutes ago, aniiran said:

Well it does, have you tested it for yourself know-it-all?   Are you a programmer can you delve into the code for us? Or you just want to sit there and tell everyone how it should work?  

He is a real 737 pilot for Alaska Airlines who knows how it works. He has spent considerable time trying to help you, and your attitude in response leaves much to be desired. 

21 minutes ago, JRBarrett said:

He is a real 737 pilot for Alaska Airlines who knows how it works. He has spent considerable time trying to help you, and your attitude in response leaves much to be desired. 

My ire for Stearmandrivers posts comes from the same place as all the other forums in this god forsaken hobby.  God forbid someone actually try to help someone with the actual problem.  Instead some "expert" with a few other "experts" come along and pile on the idea that the OP or people with a problem don't know what they are doing and offers all of these non helpful suggestions. Then 2 weeks later PMDG comes out and says our bad there was a problem with our NAV DATA packages or you need to reinstall Navigraph and update.  

18 hours ago, martinboehme said:

An alternative would be to start the approach at BORED -- this would then also allow you to fly the initial approach in LNAV, if that's your preference.

@martinboehme I tried it. Nice!  I thought the BORED waypoint might be a little boring (get it? :-)) being a bit longer route, but to the contrary, those mountains actually made it a little more interesting. Much better than what I was using earlier which was KSFO to KMRY (Monterey) which is about the same distance but over the ocean and definitely less interesting and even boring.

The bad news it is still IAN. The good news is I'm now able to auto-land. Progress.

Thank you.

It's not IAN if you got an autoland; there will be no flare logic associated with an IAN approach.  If you saw a Flare annunciation, you had a good autoland.

The reason the always-enabled IAN is a pain on the PMDG is because of an issue with the simulator itself - ILS range in the simulator is unrealistically short.  That makes it easy to end up in IAN if you're just a bit too far out.  It wouldn't happen in reality, but it makes IAN mode inconvenient in the sim when combined with that issue.

Okay, I owe Stearmandriver an apology, I was aggressive, rude, and dismissive and was convinced I was doing it right but must not have been.  I'm getting auto land to work every time at KSJC 30L in FAIL OP and FAIL PASS.  

I noticed that every time I had the problem I clicked CMD B and CMD A was clicking off automatically Therefore, giving me single channel and ILS guidance but not Autoland.  (still not sure why it acted like it auto landed)  it even flared without my input, strange.

Not sure why clicking CMD B turns off CMD A sometimes but not always.  If I hit APP>CMD B while coming onto the localizer at 30 degrees, CMD A is no longer illuminated but the aircraft will get aligned with the localizer.  Do I need to be aligned with the localizer and then click CMD B? I have tried it like 10 times with inconsistent results even when hitting the same sequence of buttons. The only thing I can do is make sure both CMD A and B are illuminated and then it works.  But then APP sometimes isn't illuminated after that even though the Aircraft is still following the LOC/VOR and G/S.  Very confusing.  

I also noticed Autoland does not come into play until 1500 feet about then it goes to CMD from SINGLE CH. 

I watched a video years ago and have been flying the PMDG the same exact way for 15 years so I thought I was doing it right.  

To be clear there is no problem with autoland at KSJC.

 

Edited February 11, 20251 yr by aniiran

1 hour ago, aniiran said:

 

Cross-posted; disregard.

Edited February 11, 20251 yr by Stearmandriver

@aniiran I wonder if the IAN thing is getting you too.  It still gets me in the PMDG, and it's not really their fault (except it would be nice if you could turn it off!) but made troublesome by the fact that in the sim the ILS range is only like 8 miles or something.

As far as the autopilots swapping - that's what happens whenever you select the other autopilot, except if you're in approach mode on an ILS.  In every other case, only one autopilot can be selected, so pressing the other button will just swap to that autopilot.  In approach mode on an ILS, it understands you want to autoland and both autopilots will show selected. 

So in the sim, what can happen is, you get yourself on an intercept and select approach, but if you're too far out for the sim ILS signal, you'll end up in IAN, which looks real similar to an ILS, it's easy to not notice.  But then the second autopilot won't take.  I've been there in the PMDG and didn't realize I was in IAN until I had that exact problem.  It's an insidious combination. 

Anyway, not saying that's for sure what happened; I wasn't there to see it.  But it's just an idea, it can get anyone.  It's cool that PMDG modeled IAN, but I REALLY wish they'd allow an option to turn it off!

 

26 minutes ago, aniiran said:

I noticed that every time I had the problem I clicked CMD B and CMD A was clicking off automatically

Thank you for mentioning this. It happened to me many times. It's very confusing for someone new to auto-landing the 737.

I'm wondering if it's an issue because of the airport, the airplane, MSFS, some combination of the three or something else.

Not-a-pilot generalizations and takeaways:

1. Just because the computer says so, doesn't mean it's always right.
2. Now I know why IRL pilots can't drink hours before flight.
3. Now I know why IRL pilots are supposed to be well-rested before flight.
4. There'll likely be two pilots always flying the in the future. See above. How else can a plane auto-land? I have no idea if single-pilot biz-jets or GA aircraft can auto-land. Can they?
5. This s* is not easy.  No wonder it's study-level. 🙂

I need more practice.