O.K., I'm new to the Airbus world on MSFS. (I had the Aerosoft A320 on P3D.)  Before going to the Fenix, I have been trying to get through FBW's tutorial flight using the experimental version (so I can get working VNAV).

I've flown it several times already, and always have the same problem.  Everything is fine until I'm on final.  Approach phase selected and confirmed, APP mode selected, both APs on, gear down, flaps dropped to 3.  I drop the flaps to the final detent...and the aircraft seems to forget anything about managed speed, drops the airspeed to somewhere around 100, and triggers the Alpha Floor protection.  Once, I was able to drop the nose, regain airspeed, and switch the autopilots back on before TOGA LOCK kicked in, and was able to complete the landing with the approach speed manually selected instead of managed.  The other times, I went into full TOGA before I could correct it, so did a go-around, flew a circuit, but, when I turned back onto the runway heading from about 10 miles out, although the G/S indicator came alive, the LOC indicator was still showing it off the charts to one side or another, although the RAD NAV is set correctly, as if it's somewhere else other than right in front of me (which it is, visually).

Any idea what I am (or FBW is) doing wrong?  I've gone over hours and hours of YouTube streams of FBW flights, and I can't see a single thing that isn't the same as I've been doing.

Edited June 4, 20224 yr by JDWalley

Well, i am surely no expert but do you by any chance have not set up the W+B during preflight? Its the second page of the INIT where you do set up your ZFW/CG and Fuel load. I am pretty sure the FMGC calculates speed using these data.

Thats the first thing i'd think of.

Best regards,

Tom

2 hours ago, JDWalley said:

O.K., I'm new to the Airbus world on MSFS. (I had the Aerosoft A320 on P3D.)  Before going to the Fenix, I have been trying to get through FBW's tutorial flight using the experimental version (so I can get working VNAV).

I've flown it several times already, and always have the same problem.  Everything is fine until I'm on final.  Approach phase selected and confirmed, APP mode selected, both APs on, gear down, flaps dropped to 3.  I drop the flaps to the final detent...and the aircraft seems to forget anything about managed speed, drops the airspeed to somewhere around 100, and triggers the Alpha Floor protection.  Once, I was able to drop the nose, regain airspeed, and switch the autopilots back on before TOGA LOCK kicked in, and was able to complete the landing with the approach speed manually selected instead of managed.  The other times, I went into full TOGA before I could correct it, so did a go-around, flew a circuit, but, when I turned back onto the runway heading from about 10 miles out, although the G/S indicator came alive, the LOC indicator was still showing it off the charts to one side or another, although the RAD NAV is set correctly, as if it's somewhere else other than right in front of me (which it is, visually).

Any idea what I am (or FBW is) doing wrong?  I've gone over hours and hours of YouTube streams of FBW flights, and I can't see a single thing that isn't the same as I've been doing.

Hm could be a lot of things you did wrong. Since it happns only once you go full flaps - are you by any chance in flaps-3-landing-mode? (perf APPR page) Could be that the FBW goes haywire if you enter a flaps 3 landing, but then go full flaps on approach.

17 hours ago, ThomseN_inc said:

Well, i am surely no expert but do you by any chance have not set up the W+B during preflight? Its the second page of the INIT where you do set up your ZFW/CG and Fuel load. I am pretty sure the FMGC calculates speed using these data.

Thats the first thing i'd think of.

Best regards,

Tom

I definitely set both of those.

17 hours ago, Fiorentoni said:

Hm could be a lot of things you did wrong. Since it happns only once you go full flaps - are you by any chance in flaps-3-landing-mode? (perf APPR page) Could be that the FBW goes haywire if you enter a flaps 3 landing, but then go full flaps on approach.

That occurred to me shortly after I posted...but I checked just now and it appears to default to a Flaps Full landing.

Apologies for not knowing the correct terms. I had the same experience. I found I had to 'dial in' the landing speed during the approach, 140 knots for example. Disengaging the 'managed' auto thrust. This solved the problem

That is definitely odd behavior. If you could provide a screenshot of the PFD when it first occurs, or even better yet, a video, it would help in tracking it down.

Have you got thrust levers on CLB position and auto thrust on?

1 hour ago, Virtpilot said:

Have you got thrust levers on CLB position and auto thrust on?

Yes and yes.

I tried several more approaches tonight, and, in each of them, I either had the speed on final drop through the Alpha Floor, or, at about the same point, the A/T disconnects and the engines spool up to what feels like TOGA without the Alpha Floor being triggered.  On a couple of occasions over the last two days, I was able to remedy the matter by, as Andy675 said, simply dialing in the V_app manually but, in one case, it simply ignored the set speed and dropped down below Alpha Floor again.  And in none of the many flights I've tried was I able to simply go through the standard approach steps, as seen in various YouTube or print tutorials, and not have it all go sideways on final.

I'd be happy to provide a video if possible.  Which replay/record add-on do you recommend?

Edited June 5, 20223 yr by JDWalley

I wouldn't use a replay tool like the MSFS build-in one. Or like FlightControlReplay. They may not use all settings you did, when doing the approach originally.

I rather would make live recording during your approach. You can use record tools like the one implemented in Nvidia Experience, or something like OBS Studio.

 

I've had exactly the same thing happen to me.  I've spent two or three weeks trying to learn this plane.  Countless hours  of YouTube tutorials, FBY Beginner's Guide, etc.

I have learned everything up to the final approach.  It seems the controls just disappear.  I am way right of the runway, my speed is way to high, and all the things you have described. That Alpha Floor thing comes on and I don't even know what that means.

Also on takeoff, if I don't engage the AP then, I can't get it to come on later.  I'm pretty sure this is something that I just haven't learned yet, but it adds to the confusion.

So, yesterday, I gave up and decided to try to learn another plane. (CJ4) From day one I have been flying GA and I wanted to move up to the big jets.

Roy

3 hours ago, JDWalley said:

I tried several more approaches tonight, and, in each of them, I either had the speed on final drop through the Alpha Floor, or, at about the same point, the A/T disconnects and the engines spool up to what feels like TOGA without the Alpha Floor being triggered

I've had this happen to me also last night. I just realized that I did not update the AIRAC for MSFS, although I did for the Fenix. So basically, I have 2 different databases. I wonder if this could be the problem?

 

43 minutes ago, airlinejets said:

I wonder if this could be the problem?

No.

2 hours ago, Roy Warren said:

I've had exactly the same thing happen to me.  I've spent two or three weeks trying to learn this plane.  Countless hours  of YouTube tutorials, FBY Beginner's Guide, etc.

I have learned everything up to the final approach.  It seems the controls just disappear.  I am way right of the runway, my speed is way to high, and all the things you have described. That Alpha Floor thing comes on and I don't even know what that means.

Also on takeoff, if I don't engage the AP then, I can't get it to come on later.  I'm pretty sure this is something that I just haven't learned yet, but it adds to the confusion.

So, yesterday, I gave up and decided to try to learn another plane. (CJ4) From day one I have been flying GA and I wanted to move up to the big jets.

Roy

https://www.aviationmatters.co/alpha-floor/

On the Approach page, did you enter the correct QNH, Temp, wind etc ... ?