A350 just took a nose dive into the runway on ILS

[gary.mc88]

Landing at Tel Aviv on rwy 26. The plane followed the ILS down to about 100ft before dropping onto the runway at a rate of -1400ft+

Is this normal or a bug or something? Maybe user error? First time doing an ILS landing with this thing - Used to using a 320 and following similar procedures so I don't think I messed anything up.

[gary.mc88]

To add

Did some testing today at GCTS. It seems that the plane struggles to keep with the vertical guidence of the ILS. It will drop below and try to climb back, but then go far and nose dive etc etc. We get this oscilation and for me its starting around 5nm from the runway. Seems it was this oscilation that caused me to nose dive at the runway originally.

This was all on A/P with A/T - I made no input just so I can see how it behaves.

[haza2]

22 hours ago, gary.mc88 said:

To add

Did some testing today at GCTS. It seems that the plane struggles to keep with the vertical guidence of the ILS. It will drop below and try to climb back, but then go far and nose dive etc etc. We get this oscilation and for me its starting around 5nm from the runway. Seems it was this oscilation that caused me to nose dive at the runway originally.

This was all on A/P with A/T - I made no input just so I can see how it behaves.

Would you be able to provide a video if able? Thank you very much.

[gary.mc88]

I did record a clip at the time to try and catch it.
It has no audio and It turns out I was only recording a part of the screen because I forgot to resize it, but you can see it going up and down. It's super obvious if you watch it sped up!

Here you go. 

I'll have to learn to use that replay tool!

[nmrdude]

I also see this exact behavior ~50% of the time.  Two flights today one OK the other last second dive city. Sometimes the speed gets set automatically rather close to the top of the low speed [.  With wind input to appr that should be padded a good bit and that might be 8 or 10 kts above the sometimes showing magenta ball.  This is on autoland properly set. Thing is it happens so fast almost impossible to disable AP and react to  try and correct and control movement with AP on is ignored completely.   Only thing I've found to help is to add speed to be ~20kts above top of [ indicator even in mild winds from any direction.

[Ollie_forum365]

I have this behaviour 100% of the time I don't fly manual landing. Exactly the same as the video quoted:

On 4/2/2025 at 8:24 AM, gary.mc88 said:

Here you go. 

Normally I would fly manual but I was just landing into Dubai with limited visibility so left it on autoland. At around 500ft the plane starting oscillating up and down (attack angle would go from 1% to 7% and back again) with massively varying throttle.

Checked all the inputs and this was fine. I can replicate this 100% of the time at any airport (confirmed it happens at Manchester, Heathrow, Hong Kong). However it did not happen until about 3 weeks ago, and the initial build would land flawlessly. 

Happens on 900 & 1000. I've not tested 900ULR yet. 

 

edit: just realised this is the 2024 forum. This is happening on 2020 as well. 

Edited Tuesday at 09:02 AM by Ollie_forum365

[Ollie_forum365]

Update: I think this is something to do with activating approach phase and managed speed. I've just done 3 landings in Dubai in the A350-1000 and the first one I activated approach phase, but for the next two I didn't and just used LOC/APPR. 

First landing - wild oscillations at about 500ft

Second and Third - smooth autoland, no issues.