Weird 747-8F behaviour on landing

[Woc 21]

Hi captains,

A few days ago I made an ultra long haul with -8F (Cargolux livery). The flight was LEMD-VHHH (13h and 25m flying). Everything went ok except a couple things that I'd like to share:

1. When pushed TOGA button for takeoff, I've got an EICAS message telling something like "RUNWAY DIS" or so. I can't remember exactly the message beacuse I was busy with takeoff procedure. The message was shown in amber with an amber CAUTION and also had an aural warning. I pushed the master cution button and both the message and aural warning disappeared so I continued with the takeoff roll. Someone have seen this before? Many years flying T7 and the Queen and it's the very first time I see this (assuming this is only related to big Boeing birds).

2. This was my second 748 flight and the second time it happens: For landing I usually set throttle fully back when GPWS says "20", a bit of flare, touchdown and apply reversers. Nothing special on it except once the main landing gear hit the runway, the plane keep a nose-up position and it's impossible to slow down. The speedbrake was automatically set fully back and switching to an outside view, I've checked the slats are up and the reversers are also working but the plane is unable to slow down. Obviously the autobrake is armed.

The first time I've got this behaviour and hearing the RAAS screaming "400m remaining, 300m remaining...", I applied manual braking and bum! all my main landing tires died while the brakes got a bright (and extremely hot) orange color. Yesterday it happened again but this time I was able to do a touch and go, fly the published missapp procedure, prepare a second approach and land the plane. The second attempt everything worked as expected and I could vacate the runway at 20-30knots with all my tires and brakes in good shape. Someone else have got that kind of ungovernable aircraft situation during landing? What I'm doing wrong? Thanks and sorry for the long post.

 

[Woc 21]

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Item 1 is probably a panel state from an earlier version.  Use only new panels with the latest version. 

Dan, I already changed the panel state to one of the new version.

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Second item doesn't have enough information... important information on landing problems would include pax/freight version, LGW, Vapp and the actual speed when thrust is reduced.  Sounds like Flaps 25 and a little extra speed but it could be other things.

Obviously I can't provide such info with accurate numbers since that flight it's already done. I'll record all that info in my next flight and if this happens again, I'll let you know. What I can confirm is this happened with the Freighter version (Cargolux livery) and I almost always use Flap 30 for landing.

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You didn't mention if you had pitch control and what happened if you had pitch control when you applied nose down control input.

Yes, I had pitch and roll control of the plane. Both times this happened, the routine was the same: a couple NM from touchdown or so I disconnect A/P and A/T and fly manually the very short final and landing. Now you mentioned, I remember the first time it happened I pushed my yoke forward to get nose down but it was like the aircraft refuse to follow my input. It suppose that as the plane was slowing down, the nose gear will touchdown...

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  Also include how much rotation you use... only about 2 deg is required and that doesn't amount to much.

As the Queen is a long aircraft, specially the -8 version, I flare with 2-3 degrees as maximum.

[LRBS 943]

4 hours ago, Woc said:

except once the main landing gear hit the runway, the plane keep a nose-up position and it's impossible to slow down.

Ivan,

Sorry to hear about that issue. Something is happening and will be investigated. We had it during testing but it was fixed long time ago.

Apparently is back and some other customers are noticing this issue.

[BlueStar 323]

4 hours ago, Woc said:

What I'm doing wrong? Thanks and sorry for the long post.

Ivan,

I've made 15 flights totaling a little over 120 hours on the B747-8F, the longest was 12.5 .  All were MZFW and most were MGTOW flights and all were MGLW flights.  I haven't experienced any of the issues that you have mentioned.  The issue with the B747-8 not slowing down on landing sounds like the engines have not gone to flight idle caused by a hardware issue.  When disconnecting the autothrottle, make sure the throttle position arcs are moving and that the sim is responding to the movement of your throttle hardware.  

Grace and Peace,

[LRBS 943]

Ivan

I did 20 touch and goes and only on 5 I noticed some floating on landing but nothing of what you mentioned as to nose up and not being able to slow down.

That doesn't mean that it will not be investigated, especially that we had that issue before.

If anybody else is experiencing the problem mentioned by Ivan please step in for the benefit of everybody.

[downscc 1,327]

Nothing of the sort; however, I did notice that there is a difference in attitude landing Flaps 30 or 25.  I'd gotten used to F30 when I first started testing and then moved to F25 where I've stayed for most missions.  I notice with F25 that flare is negligible... 2 deg at most and then I do have to lower nose but never had a problem with floating.  In my experience if I float a landing it was because I had mismanaged the speed regardless of airframe.  In my opinion the -8 is a more enjoyable aircraft to fly than the -400.

[Woc 21]

Well...tonight I'll give it another try. I'll do another flight and will pay special attention to final app and landing procedures, write down all data and be back to you guys with final results regardless it would be successful or not. Thanks a lot, guys. Your feedback is very much appreciated.

[MattS 45]

I have seen that same issue (2nd one) in the 747 and 777, all models, so I don’t think that it is aircraft specific. In fact I had it on Saturday in the 77W. It only happens when I try grease a landing instead of properly flying it onto the runway. I wouldn’t be surprised if it is some sort of P3D limitation or something. As long as I don’t try and impress my passengers, it’s all good...

[MattS 45]

I should also mention, for me this phenomenon is very rare. 

Edited October 15, 2018 by MattS

[Woc 21]

Hi captains,

This morning I've made a short test flight (LEPA-LEBL, both payware sceneries. 133NM) slightly loaded and everything went perfect except an EICAS message telling me that seatbelts are OFF. No matter if I set the button to AUTO, ON or even OFF pposition. The EICAS message is still there. Even if I set the button to ON, then I see "SEATBELTS OFF" and "SEATBELTS ON". Both messages together on EICAS. (pic attached).

As per the test flight and as promised, here are the fuel loaded:

...the payload:

and the takeoff weight:

 

Today I did a Flap25 landing. I also made a video from the cockpit with all approach and landing but it's too heavy for share (almost 20GB...). Right now I'm on my way from VHHH to PHNL. Still 6h and a  half to go. I'll let you know if there's some issue.

PS: okay, I'll follow the instructions on the thread about how to fix EICAS messages that do not clear and will see what happens.

Edited October 16, 2018 by Woc

[Woc 21]

Well, to finalize this thread, I have to say that nothing is wrong with the -8 but me 😔 I simply need to practice since the -8 is notably different than the -400. And that's it. Thanks again PMDG for bring us another piece of software that is a true marvel. Happy flying, captains😎

Edited October 18, 2018 by Woc

[downscc 1,327]

18 hours ago, Woc said:

Well, to finalize this thread, I have to say that nothing is wrong with the -8 but me 😔 I simply need to practice since the -8 is notably different than the -400. And that's it.

The differences between the -400 and -8 are many but none as significant as the entirely new wing and engines.  I hope you enjoy flying her as much as I do... she is a very powerful and graceful lady.

[Woc 21]

On 10/19/2018 at 1:18 PM, downscc said:

I hope you enjoy flying her as much as I do

I will!!  😉

[Ephedrin 418]

Sometimes it‘s not the pilot and not the airplane... when you run into braking issues or sonething you can’t explain don‘t forget we are in a simulator environment... I haven‘t checked that for months but I had an issue with the FSL A320 landing and not braking in ORBX Bilbao LEBB. It turned out that the scenery developers have treated their runway with oil. No idea why, they said in the Ftx forums that it was made for some reasons to trick some issues. Obviously I though first there was an issue with the Airbus and together with some guys over at the FSL forum there was a long thread about it. Until I and someone else went to FTX and they promised a fix... this was under P3Dv3.4 and since then nothing has happened. No idea if it’s fixed by v4. There‘s so much involved into our sims that it‘s getting harder and harder to find any culprits or identify any bugs... So there might still be an issue with the 747 as it was said there were several „complaints“. Keep an eye on it and if it happens again everyone should feel free to come here and provide as much info as possible 😄 imho xD