Jump to content

Sign in to follow this  
Pineapple_Wizard

Landing the 777, what's going on?

Recommended Posts

18 minutes ago, downscc said:

You over rotated.. your rotation was at least 5 deg... keep it close to 2 deg. The nose should come down within a few moments, applying reverse thrust as mains touchdown also pushes nose down.

Dan, are you reading anything typed? Something has changed to cause this problem to happen, and several people have noticed it when it didn’t happen before.

When this happens I am unable to apply reverse thrust until the nose touches down. A clear indicator that the airplane does not think it’s on the ground. My flight last night ended on a normal landing, much to my surprise, and it was literally no different than the one in the video except everything worked as it should and allowed me reverse thrust as soon as the mains touched down and the nose came down naturally as it always did before this started happening. In fact, in my flight last night I purposely rotated more than I did in that video and it still worked perfectly.

Something is causing the issue and I came here to chime in with others to see if we could try to locate the cause. You may not have the issue, but there’s no reason to aimlessly keep suggesting everyone is doing something wrong in landing when, at least in my case, I’ve changed nothing in all the time I’ve flown the thing. Yet, the problem started a short time ago and still persists.

Edited by FDX016 - Nick

Thanks!
Nick Crate
Chief Executive Officer
FedEx Virtual Air Cargo

Share this post


Link to post
Share on other sites
38 minutes ago, FDX016 - Nick said:

Something is causing the issue and I came here to chime in with others to see if we could try to locate the cause.

I think it is pilot technique.  I land it like I do the MD-11 with 200-300 fpm touch down rate and have no issues with the B777 or the B744. 🙂


Beta Tester XM-26 Tow

Share this post


Link to post
Share on other sites

Just a thought, a controller issue? Maybe throttle hardware isn't calibrated and actually doesn't go to idle and overrides the autothrottle before you try engage reversers?


 

 

Share this post


Link to post
Share on other sites

If it is landing technique, could you please explain what physic make the aircraft perfectly stable with the nose up like this ?

Just to clarify, I've been flying realistic sims since at least 10 years (Level d 767, PMDG, FSLabs, Qualitywings 787), had made thousands of landings, and never encounter such problems so far. And you keep thinking it's pilot technique ???

It's not a problem of an uncalibrated throttle because I've checked it, specially while taxiing. The N1 settings wasn't rising at that moment, but the speed was "flashing" on the PFD between 0 kts and 130 kts (meaning it comes to 130 kts, then immediately to 0 kts, and immediately to 130 kts again).

I know it's a bug on the airplane. Specially when I discover that braking manually the aircraft stop that "wheeling effect". The wings lose lift and the nose start to come down.


Alf DAGNON - Flight enthusiast

VA France - AF024

Share this post


Link to post
Share on other sites

Sorry to disappoint, but the product has been out for years and event subjected to a second round of tests before releasing updates for P3Dv4 and there is not a bug with landing other than the already acknowledged one with lack of deceleration with nose gear in the air.

Thinking of you, the other day I was flying a B77L into PHOG  RNP Z 02 (6995 ft) and winds were 080/15G23 so I added 4 kts to my Vref of 137 such that Vapp increased from 142 to 146 KIAS. I used autothrottle, as is my norm for the 777, and had no problem cranking in reverse thrust as the mains touched down about 1500 ft along and I was able to slow for turnoff using autobrake 3 with about 600 feet remaining as predicted by TOPCAT.  If there were a bug I could not have done that.  I've performed this approach with both F25 and F30 without landing issues.

The one thing interesting about that approach was that because the default ND runway length display filter is 7000 there were repeatable false terrain warnings..no where in the documentation does PMDG tell us that this "display" setting also affects what the GPWS filters out.  Once the ND "display" setting was reduced to 6900 the false warnings went away.  I'll be suggesting a minor edit to the Introduction next time I get a chance.

Edited by downscc

Dan Downs KCRP

Share this post


Link to post
Share on other sites
1 hour ago, downscc said:

Sorry to disappoint, but the product has been out for years and event subjected to a second round of tests before releasing updates for P3Dv4 and there is not a bug with landing other than the already acknowledged one with lack of deceleration with nose gear in the air.

What do you mean the acknowledged bug for lack of deceleration with the nose gear in the air? In FSX or just P3D? That's exactly what we are talking about........

I did a flight the other night and did not record my landing, but I wish I did. Calm wind, planted the mains (I think it was -280 vs) and released all pressure from my controller to try to test this. I held in my button for rapid "F2" repeat and watched as the speed tape flashed about 6 times in 3 seconds between no v-speeds (like I'd touched down) and back to the VREF showing like I hadn't. It would not let me go into reverse and I GAINED 3 knots. Engines at IDLE thrust this entire time. I let it go for about 4-5 seconds before I reached and pushed the nose down so I would not run out of runway. As soon as the nose touched it was all back to normal. This being said, I'd done something like 6 or 7 flights in the last 10 days and only one of them resulted in a normal touchdown where I was able to start reverse thrust immediately while the nose was still in the air.

Dan, I'm not trying to cause an argument or disagreement but we will just have to agree to disagree. As I've said before you clearly do not have the problem those of us on the thread are having. We are having the problem (it's definitely a problem) and came here to try to find a solution, whether it be a bug in the 777 or another addon that is interfering with the airplane and causing this.


Thanks!
Nick Crate
Chief Executive Officer
FedEx Virtual Air Cargo

Share this post


Link to post
Share on other sites
5 hours ago, AF024 said:

-snipped-

I know it's a bug on the airplane.

-snipped-

I am not sure it's the airplane just yet. I have some questions:

  • Would you mind listing what addons are in use while you are flying the 777?
  • Are you on FSX or P3D? What version?
  • Do you use FSUIPC?
  • Do you have addon scenery for where you fly? What about just AFCADs?
  • Does this happen every single time or have you had times where it does not?

Just trying to see if we have some similarities that might be the culprit.


Thanks!
Nick Crate
Chief Executive Officer
FedEx Virtual Air Cargo

Share this post


Link to post
Share on other sites

I confirm there's something out of order in this regard with the B77W which wasn't there before, it just happened to me today. I've been using the Triple Seven since the FSX days and never noticed this before. Then recently after several months away from the plane I returned to it noticed a few glitches that weren't present before.


Best regards,

 

Wanthuyr Filho

 

qpwqa8-6.png

Share this post


Link to post
Share on other sites

After seeing this post a couple of months ago, I had this Issue happen to me for the first time tonight.

I am not even in doubt that there is something wrong here (i've flown both the PMDG777-200 and the 300 a lot) The way the aircraft behaved after the main gear touched down was completely different to anything i have seen before and exactly as described by others in this post. This was into 30L in OMDB and the 77W usually stops fairly quickly. But this time it just kept the nose up by itself until like 2/3 down the runway making the nose come down just in time for the brakes to work making the aircraft stop just short of running off. i touched down with a 200fpm'ish landing just on the touch down marker.

i will try and see if i can make some footage of it.

P3D V4.3.


Frederik Pedersen

Share this post


Link to post
Share on other sites
13 hours ago, Chok said:

I am not even in doubt that there is something wrong here

I don't have any problems with it and one of the guys I play beer league hockey with flies my sim from time to time and he doesn't seem to have any problem with it.. 

If the airplane is flared prior to the engines going to flight idle, it will float and the engines will not go to flight idle.  I hold the deck angle constant from about 100 agl until the engines start going to flight idle and then increase the deck angle no more than a couple of degrees will help.  


Beta Tester XM-26 Tow

Share this post


Link to post
Share on other sites

I was always taught to “fly the nose to the ground”.

 

When flying a jet that is ~75m long, a simple let go of the control wouldn’t work. On the real airplane, if you don’t fly thennose to the ground it will slam on it. 

Because when the spoilers are deployed after the main landing gear touched down, the center of pressure of the Wing changes and the airplane will have a tendency to pitch up. Exactly like what it would happen when in the air except this time fBW is in direct law and won’t help you to correct it. 

Usually this pitch up moment is canceled as the autobrake begin to apply braking and the reverser are deployed. But this “pitch up after touch down” has happened to me in real life and I had to help to nose to come down by actively flying it down including putting in slight forward pressure on the control column. 

 


Wing Lai

i7 6850k OC to 4.0GHz / Asus x99-Deluxe II / CORSAIR DDR4-3200 64GB

EVGA GTX 1080 / SAMSUNG NVMe SSD 950pro 512GB / Samsung 850 pro 512GB 

3x EIZO FS2434 24" Displays

Share this post


Link to post
Share on other sites
41 minutes ago, Driverab330 said:

I was always taught to “fly the nose to the ground”.

My hockey buddy says you need keep pulling back on the yoke of the B777 to hold the nose off of the ground or it will slam down. 🙂

 

Edited by Bluestar

Beta Tester XM-26 Tow

Share this post


Link to post
Share on other sites
37 minutes ago, Bluestar said:

My hockey buddy says you need keep pulling back on the yoke of the B777 to hold the nose off of the ground or it will slam down. 🙂

 

Initially, we relax the back pressure to help to nose to come down, because if we keep pulling back the nose will stay up in the air until the elevator loses the lift then slam down.

basically, we all fly the nose down in a consistent rate of de-rotation until just before the nose wheel touches down then we sort of do a "little flare" to cushion the last bit. 

As to how much you need to pull back depends on the CG and Autobrake settings, in A/B 4, we will need to pull back a bit more at the last stage to arrest the "slamming motion" of the nose. A/B 3 or less requires much less effort. 

What I just talked about was the moment just after the main gear touched down, at some condition the nose will tend to come up after the spoilers are deployed, so we relax the back pressure but we don't think what we do in real life before we do it, just like a rotation on take-off, just do what we need to keep the rate of de-rotation consistent. 

 

**A little story just happened to me recently on Take off on an A330, I rotated normally but when the pitch attitude went passed 12.5 deg, the nose suddenly pitch up dramatically, and I had to give it a push forward a bit very briefly on the side stick to arrest the pitch up. Therefore, it is important to look outside and just react to what we see. ** 

 

This de-rotation technique on landing is no different on the Airbus, just fly the nose down. 

 

The whole idea is to do whatever we need to do "to keep the nose coming down at a controlled and fixed rate of de-rotation"

 

Having said that, throughout my whole career as an airline pilot I only ever fly FBW jets, so unfortunately I am not sure how the old jets behaves on landing. Because FBW airplanes (both A330 and 777) behaves quite similarly and have a very consistent handling chariteristics in all flight phases. 

 

However, I have never heard of people including those who used to fly the “classic 747-100/200 or Tri-Stars” complain about the 777 de rotation, therefore the technique must have been the same. 

Edited by Driverab330
  • Upvote 1

Wing Lai

i7 6850k OC to 4.0GHz / Asus x99-Deluxe II / CORSAIR DDR4-3200 64GB

EVGA GTX 1080 / SAMSUNG NVMe SSD 950pro 512GB / Samsung 850 pro 512GB 

3x EIZO FS2434 24" Displays

Share this post


Link to post
Share on other sites

On the real 777, your autobrakes kick in on main strut compression. You will always have to hold the nose off the ground to prevent it from coming down. Even with the autobrakes off, the deceleration after landing will (at a slower rate) cause the nose to drop towards the runway fairly quicky. The term fly the nose on to the runway simply means, to control it’s touchdown as you would the mains. It doesn’t mean you need to push the nose down, otherwise the nose takes forever to drop.

  • Upvote 1

Xander Koote

All round aviation geek

1st Officer Boeing 777

Share this post


Link to post
Share on other sites

I want to chime in support of those who are encountering this problem. May 30, 2017 was a big day for me in my long-ish flightsim career (FS1 on MS-DOS is my beginning and Flight Assignment ATP was my introduction to my love of tubeliners). That date (May 30) was a big one as 64-bit P3D meant that my love affair with long-haul was back on the menu.

As soon as the 777F and 744F (God, please please please convince PMDG to bring me my MD11F to complete the trifecta) were made available in P3Dv4, I've stuck to the following pattern nearly perfectly except for travel, illness, or some other uncontrollable circumstance: I fly 2 days on the B744F and 2 days on the B777F and then take a break for a day.  I've got the flight logs to prove that the joys of legs like EGLL to KLAX (last night's journey) are available to me.  With auto step-climbs, pause at TOD, and auto tank-to-engine, PMDG has really afforded me to fulfill my desires by letting me studiously plan a journey, prep the flight, fly to cruise, and then go to bed.  I wake up, put on coffee, and study what the descent and approach will be like.

This is a highly fulfilling pattern for me and I am VERY GRATEFUL to PMDG for making this a reality for me.

So, that long preamble was meant to establish the following:

  • I fly the 777F anywhere from 2 to 4 times per week
  • I bought the paper manuals from PMDG back in 2013 and study them often - I am familiar with all recommended techniques and speeds; even if I am an average pilot, I am in good practice
  • I get to land in a variety of conditions

With that preamble and those caveats I would like to fully support the OP's (and Nick's) observations that something isn't right at all. I experience everything described and it is seemingly at random.  This behavior OFTEN ruins flights and I've tried about everything (reset couatl after pushback, reset traffic, etc.).

Here is an illustration: using the manual and TOPCAT I should be able to land on Runway 5 at RJTT with in a B777F.  However, this floating non-deceleration made for a HAIRY situation there just a few nights ago for me.

Nick, one thing I can perhaps think of is that P3D remains somewhat "squirrelly" the longer it runs.  I've had numerous "black hole of newfoundland" problems in the past thanks to Couatl. Indeed there are many "dances" I feel I have to do to keep this sim running correctly (deleting shaders when the video card drivers are updated comes to mind).

So, in addition to your list, I would put forth the simple act of being airborne for 8+ hours.  This is not a support forum and we will likely need to submit a ticket.  However, just as is the case with Lockheed Martin, many support encounters end with the vendor seeking to isolate their products from others - which is understandable.  So, PMDG will want you to strip down to just Vanilla + PMDG to really take your problem seriously. Lockheed Martin will expect you to reinstall or clear all files such that you are effectively reinstalling.  So, i think the "gumbo" of add-ons we use to heighten realism - FSUIPC for the things that require it, Active Sky to get real-time weather, shaders to make her look prettier, EFB add-ons to monitor progress, and so on - these things all add to the "mystery tour" that is successful outcomes.

The recent update from last week did not erase these issues as my RJTT experience was the day after I applied the update.

So, yes, something is rotten in Denmark and we got trouble, right here in river city.

Lastly, I find Dan to be often helpful, but he's giving well-intended answers that cover most "low-hanging fruit" cases.  Sometimes I wish we could take proficiency/competency tests and display badges that demonstrate that we have achieved this proficiency.  Otherwise, it is very difficult to calibrate what others know and don't and attempts to help are almost always all over the map (ranging from useful to apocryphal).

 

Edited by ahuimanu
corrections

Jeff Bea

I am an avid globetrotter with my trusty Lufthansa B777F, Polar Air Cargo B744F, and Atlas Air B748F.

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this  

  • Tom Allensworth,
    Founder of AVSIM Online


  • Flight Simulation's Premier Resource!

    AVSIM is a free service to the flight simulation community. AVSIM is staffed completely by volunteers and all funds donated to AVSIM go directly back to supporting the community. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. Thank you for your support!

    Click here for more information and to see all donations year to date.
  • Donation Goals

    AVSIM's 2020 Fundraising Goal

    Donate to our annual general fundraising goal. This donation keeps our doors open and providing you service 24 x 7 x 365. Your donation here helps to pay our bandwidth costs, emergency funding, and other general costs that crop up from time to time. We reset this goal every new year for the following year's goal.


    2%
    $705.00 of $25,000.00 Donate Now
×
×
  • Create New...