Jump to content

Sign in to follow this  
Guest EDSJ

double touchdown

Recommended Posts

Guest EDSJ

Hello Captains,i have a problem with my 800. If i touchdown on RWY every time i make a double touchdown. I haven't this problem with 600/700. i'll try all... Very Slow touchdown or anything... If talk about 2 other user's and they have the same problem, too. Is that a model problem?

Share this post


Link to post
Guest Exu

Hi;I noticed this too, when I do a full autoland in the 800/900, at touchdown, the aircraft bounces back up a bit, my autospoilers are armed (and deploy), autobrakes set at 2, comming in on Vref exactly spot on, and she bounces once, and this, on every landing.Not many pax cheer when I land.:-lolEric St-Louis

Share this post


Link to post

Funny I have never bounced! But really we are not in your cockpit and how you flew the 700 does not help since they are 2 different aircraft! General statements are not helpful please be more specific, what model 2d only? VC and cabin? What livery? What was your landing weight? Dual autoland? Ref speed is VREF + 5 MINIMUM! What flap settings on landing? Where were you landing? What season and what airfield? So please for us to help you be specific and give as much details as you can. [h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

Share this post


Link to post

Hi guys,Just made a short flight with a full dual A/P autoland with the -800 2D model. GW was 64 something tonnes and the Vref was 148KIAS for final. Not a single bounce. Spot on.As Randy said, some more facts would be great for us to see what's going wrong.Cheers,

Share this post


Link to post
Guest Exu

I tried it with the American Airline 800 2D and VC, GW was 137.5 thousand pounds. vref was caclculated (15 SM from touchdown) at 144 in the FMC at 30 flaps, RW 24R, CYUL. I am using Active Sky 2004, but I don't think this is the problem. Tried the landings first at Vref + 5, and vref, dual channel AP full CATIII autoland, still bounces.Also tried a landing in live spot view, and I could clearly see that she goes back up and then down. ( saw two puffs of smoke from the main landing gears).Am I doing something wrong??:-zhelpEric St-Louis

Share this post


Link to post
Guest EDSJ

Ok,i have try it on many airports with and without scenery. Air-Berlin 2D and Virtual Cockpit with WL. 130 Knots, flap 40 and with 100feet/min... Thats not only my problem. 3 friends of me have the same problems. I fly manuell without AP and very very slowly... But every time double touchdown... I've the same problem as Eric. :(

Share this post


Link to post
Guest EDSJ

Ok,i have try it on many airports with and without scenery. Air-Berlin 2D and Virtual Cockpit with WL. 130 Knots, flap 40 and with 100feet/min... Thats not only my problem. 3 friends of me have the same problems. I fly manuell without AP and very very slowly... But every time double touchdown... I've the same problem as Eric. :(

Share this post


Link to post
Guest EDSJ

Ok Guys,with 135XXX lbs and 20% left 5% center and 20% right, full flaps (40

Share this post


Link to post

I really don't know nameless :-((Pst, please sign your posts with your real name as per the forum rules)I have yet to see the bouncing since I haven't seen it on any landing I've done yet.Wanna take us through your landing, step by step? Exactly everything, and I mean everything you do while on approach and finally landing.Can you also provide the aircraft.cfg for the aircraft you are experiencing this with?Cheers,

Share this post


Link to post
Guest BernBear

Well,I never experienced bounced landings in the 6/700, but the 8/900 bounces on pretty much every autoland.Here are the details for my latest landingContinental 900, 2d only, ZFW 137,000 lbs, landing weight 145,000 lbsLanding at KLAX ILS 7L, Flaps 40, VREF 141, wind correction +5, FMC speed 146, Speed over the threshold 146 KIAS. Wind 090/11Both APs on, both NAVs tuned to the correct ILS frequencyA/T disarmed at 20ft RADIO, very hard touch down, bounce.I have a very hard time getting the 8/900 down on autoland without bouncing, althought the 900 is much more "bounce-prone".I try to follow checklists to the letter, always cross the threshold at VREF+5, always with flaps 40 (I hear that's how it's usually donw with the 8/900)Best RegardsMax (Bern, LSZB)http://www.hifisim.com/images/as2004betateam.jpg http://www.precisionmanuals.com/images/forum/800driver.jpg

Share this post


Link to post
Guest Exu

Hi RandyI also bounce with the 800/900. In spot view , I do see the flare and then the bounce. I don't have this problem with the 600 (didn't try the 700 since upgrade)RegardsEric St-Louis

Share this post


Link to post

EricNot to be rude, but you mentioned this in your first reply in this post. ;-)Better if you provide us with a complete listing of what you do when you land. And I mean everything! ;-) Provide screenshots of your main and ocverhead panel, aircraft.cfg, screenies from the bounce, lists of what you where doing. Anything that will help us narrow down the cause for this behaviour!Thanks,

Share this post


Link to post
Guest Lenny Zaman

guys, i just landed from a very long haulerEBBR KJFK with a stop in CYQRjust landed in JFK, rwy 31L(raaaaaaiiiiiiiny :() did it 100% by hand ,not a bounce but thats not the issue i guess!i also did some autolands earlier on and i never had the bounce issue... what were your framerate when passing over the thresshold?if low, then it is normal that everything slows a bit down including the autopilot input, thus getting a little bounce wouldn't be awkward then.

Share this post


Link to post

This is really a difficult issue mainly because some do not see this bounce, logic tells me that if the aircraft is bouncing it is coming down too HARD so then I am wondering if there might be some wind componate issue that the A/T cannot deal with over the LTP since the A/T are going to IDLE. I would REALLY like these folks to try it without weather so we can narrow this down..[h4]Best Wishes,Randy J. Smithhttp://www.precisionmanuals.com/images/forum/betaimg.jpgAMD 64 3200+ | ASUS KV8 DELUXE | GFORCE 5700 ULTRA @535/1000 | WD SATA 80 GIG | 512 DDR 400 |

Share this post


Link to post
Guest Exu

Randy;Tried a circuit with no weather, Delta Airlines 800, GW was 137.3 k pounds, FMC called for vref of 138 at flaps 40, came in at 143 and had the bounce. This was a full Autoland.Here is the weight and balance section of aircraft.cfg[WEIGHT_AND_BALANCE]reference_datum_position= 52.786, 0.000, 1.861 // Vector of Boeing RFP to visual mode centre !! People DO NOT TOUCH !!empty_weight_CG_position=-57.770, 0.000, 0.000max_number_of_stations=50empty_weight=91300.000empty_weight_roll_MOI= 1630328.70empty_weight_pitch_MOI= 2103844.05empty_weight_yaw_MOI= 1754301.78empty_weight_coupled_MOI=202.00//station_load.0=900.0, -57.450, 0.000, 1.050//max_gross_weight=173000.000CG_forward_limit=0.133CG_aft_limit=0.330station_load.1=12240.0, -57.450, 0.000, 1.050station_load.2=10604.0, -57.450, 0.000, 1.050station_load.3=9955.0, -57.450, 0.000, 1.050Mats:Sorry can't give you any screenies as I don't know how.Lenny:FPS was 29.9 locked at 30Thanks guys, for trying to help us with this problem.:)Eric

Share this post


Link to post

I finally got the FMC problem solved. It was in the route. It was not selecting the IAF. I think it's left for the pilot to select depending on conditions, etc.As far as the bounces: I did bounce also at published speeds and config's, BUT: when I replayed the video I pulled up over the numbers. I think this is due to the eye point view from the 2d panel. It looks like you're in a dive when in fact your already in a flare. My guess is when you do this the airplane at Vref still has enough forward momentum to keep flying for a while and even climb a little. Flying as a passenger in 737's for all of my 33 years I have also noticed that the airplane seems to be very "light on it's heels" if you know what I mean. I've bounced more than twice before while riding as a pax. I think the 737 is inherently "floaty" in my opinion.

Share this post


Link to post
Guest Panman

One trend that I have noticed is that people are mentioning their landing speeds but not their vertical speeds. I always aim for 200 fpm or less during the flare.Aaron-oOo-

Share this post


Link to post

You should not be watching VSI during the flare...Retard the throttles slowly at 30ft so as to be at idle when the aircraft touches down. At 30ft calmly raise the nose 2-3 degrees from the normal approach attitude and keep it there. Then accept the touchdown, don't try to adjust and finetune it anymore than that. That is how the landing is done IRL, and it should work here too.Tero

Share this post


Link to post
Guest thscholz

>> General statements are not helpful please be more specific,>what model 2d only? VC and cabin? What livery?>Randy,what livery?:-hmmm :-lol Did PMDG implement better or worse pilots depending on the airline?CheersThomas

Share this post


Link to post
Guest EDSJ

Hello there,ok tero i try it. Watch this Video... If i watch correctly, the model touchdown and after this the gear. You can saw it about sinkrate is stopping... Look here:http://www.cadp.de/video/pmdgland.mpg...without any ideasSwen

Share this post


Link to post
Guest aaron_huber

I think the question is not about manually landing but about the autoland feature. I can grease it down pretty well manually but I get a bounce every time when doing an autoland.Do you get a clean landing when watching from spot view when in full autoland?Aaron

Share this post


Link to post
Guest filip146

Maybe the spoilers did'nt deploy on touchdown?Because of an unknown reason, I cannot arm the spoilers anymore using SHIFT /, only by clicking on them I can. This is the case for all aircraft including the standard planes, excluding Phoenix Software A330/A340 which is working fine...I landed once with a -900 with spoilers armed illuminated but lever in the down position and.... no spoilers on touchdown and double bounce with alot of smoke.... So there was a mismatch between the indication and the position of the lever.It's too late know (01:50AM) here in Belgium... I am going to get some sleep and try some things tomorrow!Happy flying,Filip.

Share this post


Link to post

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  
×
×
  • Create New...