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Sekkha

Autoland touchdown 500+ ft/min - updated groundeffect ? 744

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just tried my first autoland after the update and the plane touched down with over 500 ft/min....

so I tried another airport , but the same result...around 500 ft....this used to be very smooth before the update..

both landings with 0 wind ..

has the autopilot still to update his landing technique with the new groundeffect ?

best regards

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I don't know of any pilots that watch the VSI during landings,  and for your consideration anything below 800 fpm is problably a good landing.  One thing I know for sure, smooth landing is not a criteria for safe landing. 

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53 minutes ago, downscc said:

One thing I know for sure, smooth landing is not a criteria for safe landing. 

Too true! Go NAVY! 😉

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yes, ground effect has been reduced in this update. I have pointed out at first day when update released. but no one care. and the anwser is the ground effect is 300% before update, and now it is 100%. so, this is good news for 747-400, 747-400F, and 747-8, because they never float too far any more, all you have to do is start flare earlier and hold the nose up, And its is bad news for a max loaded 747-8F, it need more technique to land it properly.

I've tried 744 74f 748 748F landing after updated. the conclusion is new ground effect is more real world like, so I have to practise landing 747 as a new plane, espcially max loaded 748F.

I have to too say, this update is really huge and unexpected, it shocked me when I first landing 748F after updated.

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Haven’t done the update yet but I’m glad to hear this was done. In the real airplane I usually start the flare after the “40” callout... but in the sim that has always resulted in excessive floating. Sounds like this will be more true to life.

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Posted (edited)

I can tell you from firsthand experience the autoland in my aircraft at work is often “firm” to say the least. In fact, we hate it and don’t really trust it. In addition to it often landing hard, it will occasionally drop the nose at the runway, or fail to correct quickly enough in gusty winds. It can get really uncomfortable! It’s not uncommon at all for us to disconnect it in the flare and complete the landing if safe, or just go around. But, then there are days where it works perfectly... these machines are temperamental!  Now bear in mind my aircraft is based on a 747-200, so a much earlier version of the autopilot.

I think we are often spoiled in the sim with aircraft and systems that function to perfection all the time. In the real world these things age, have issues, and often act up. Just cause it can autoland doesn’t alleviate you from your duties as PIC or Captain. If the automation isn’t performing, disconnect it and fly the dang plane!

Edited by Jason_Peters

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When the B744 and B747-8 were certified by the FAA the maximum landing rate at max. gross takeoff weight is 6 feet/sec (360 fpm) and at max. gross landing weight it is 10 feet/sec (600 fpm).  

At approximately 35 feet agl, the autopilot will flare the aircraft approximately 3 degrees and the throttles will retard.  If the aircraft has not flared, the pilot flying will flare the aircraft the required 3 degrees and verify the throttles have retarded (simplified version). 🙂

Grace and Peace, 

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1 hour ago, Bluestar said:

 If the aircraft has not flared, the pilot flying will flare the aircraft the required 3 degrees and verify the throttles have retarded (simplified version). 

🙂

Grace and Peace, 

Just moving the controls or disconnecting the ap first? Sure, in reality this is not as difficult as in the sim as the yoke actually moves as it would if flown manually, but in the sim this would likely cause a „control warp“

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Posted (edited)

Thanks for your replies everyone !

I know very well  that a smooth landing is no criteria for safe landing and my question was not aiming at that at all. 

In about 5-6 test autolandings I did now the touchdown rate was consistently more than 500 ft/min, the last one at max landing weight was quite close to its certfied limit of 600 ft/min.  So I find it reasonable to ask if the RW autopilot is really designed to get every landing close to the limit (and I know that the autopilot is not designed to archive a smooth landing) or if it wouldnt flare a little bit more..... I mean with the ever so slightest windshear this limit will be hit.

In regards of handflying I am also very happy that they updated the groundeffect because my feeling also always was that the plane was floating too much (and many times lifted off a little bit again after first touchdown - hope that is better now, too)

 

3 hours ago, Ephedrin said:

Just moving the controls or disconnecting the ap first? Sure, in reality this is not as difficult as in the sim as the yoke actually moves as it would if flown manually, but in the sim this would likely cause a „control warp“

yes, that would be interesting how to do it

 

best regards

Edited by Sekkha

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6 hours ago, Bluestar said:

the pilot flying will flare the aircraft the required 3 degrees

to an attitude of ???? ......

 

1 hour ago, Sekkha said:

the yoke actually moves as it would if flown manually

it's not trimmed by the autopilot ??

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21 minutes ago, vadriver said:

 

 

it's not trimmed by the autopilot ??

The trim is not there to fly/steer the airplane. It is used by the AP during level flight but as soon as the FD requests another flight attitude like for a turn or to decent, climb, flare... it will use the normal controls, that‘s what they are there for.

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12 hours ago, Ephedrin said:

but in the sim this would likely cause a „control warp

Not in a $25 million CAE sim.  🙂

Grace and Peace, 

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5 hours ago, Bluestar said:

Not in a $25 million CAE sim.  🙂

Grace and Peace, 

Sometimes I feel my P3D might be very close to that amount 😂

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