Speedbrake Deployment & Bounce Landing

[Guest wee_davie_2612]

Hey all,I bring with me new pics in the form of a slide show. This time a full autoland (actually the same setup as the previous pics - 700, no weather, max landing weight, flaps 30 etc) from the cockpit with an auxiliary window showing the bounce from outside aswell.The slideshow can be found [a href=http://www.ibsw08346pwp.pwp.blueyonder.co.uk/700slideshow/pmdg700fullcp/Cache Page.htm]here[/a]Have a good one,David

[Guest venquessa]

I'm in this too. After all my ranting I surrendered and bought the 800/900 upgrade.First landing and every landing since I bounce and float for about 3 seconds, at less than a foot AGL, then settle down. Two decrete sets of tyre marks and two puffs of smoke. Speed brakes and idle all appear to be working, A/T disconnects, spoilers deploy, autobrakes engage.Apart from the upgrade I changed nothing about my landing style. I haven't done a lot of the testing you guys have, except to ensure I am using the exact same procedure for landing, FMC Flap 30 VREF + 5 from about 5 miles out on GS, 30 degree flaps.Here's one thing I can add, as I was yesterday flying a lot in the 700 and then upgraded and spent all night flying the 900, I are a fresh set of eyes.I would swear it's diving for the T/D zone and flaring about 1 sec too late, it seems hurried, were as the 600 pre update was laid back about the flare. I think it is still flaring when it touches and it touches slightly too hard, so it skips and floats.I have to sleep now, but can I suggest those up for testing find a way to record the TD G load and V/S, trim settings and, if it's possible control (A/P commanded) positions?I might well be wrong, but I think the flare is heart of the bounce issue. The spoiler and A/T idle, RETARD problems I can't be sure of, I know mine cuts to idle about 30AGL and discos just after touch down.The spoilers don't fire on the first touch, but as the wheels are only in contact for 1/10th second or less, you probably wouldn't see them move at all anyway.In the meantime, while people test and diagnos the phenomena I will try flaring manually (or assisting when I think it's a bit hurried) and see if "I" can prevent the bounce.HTH

[Guest jacaru]

I having the same sensation with the flare. I will try with the 700 and compare. See if i can get that data for both situations.How do you notice idle throttle at 30' AGL??Jaime.

[Kosta 122]

Replying to the first post, to get the posts to appear on the left side again:To do some more testing, I did 3 absolutely same flights, except each flight was a different model: 600, 700 and 800.I acted the same in all 3 landings, 100% same procedure.All PMDG aircraft have the "same" load. Full PAX (single), 10 bags more than PAX (say if 180 PAX, then 190 bags, each bag 13KG). This should approximately yield the same results, or?To make it clear, this was all full auto landing (2 autopilots, S/B in armed position - armed manually with the mouse on the throttle console).Results and differences I noticed:737-600Pitch about 4-5 degrees up while on the glideslope, seemed pretty nice and right (I don't own AOM or so, so I can't say what's right). Flare lasted about 5.5 seconds, from 50ft anunciation until touchdown, speedbrake deployed OK. Upon initial touchdown, S/B extended alright, although I noticed a very very VERY minor bounce. Nothing I would notice if I wasn't looking for it.Also noticed throttle go to idle position prior to touchdown.All in all, OK.737-700Pitch was less, around 2-3 degrees. Flare was noticeably shorter (didn't measure, but I'd say for about 1 second shorter). At the touchdown, it bounced longer than the -600 model, what was very easy to spot, but after that one bounce, it extended the speedbrakes and settled down on the runway. I noticed throttle entered the idle position while in the bounce.737-800Pitch was almost 0 degrees. Flare was again shorter, but I can't say now if even shorter than -700 model, but definitely again shorter than a -600 model. At the touchdown, there was one very long bounce, I think there was even a 2nd bounce, but not sure now about that. Throttle entered the idle position much later than a -700 model, and that was actually when aircraft settled on the runway, after it bounced. But this time, speedbrakes didn't deploy. My guess is, if the throttle manages to enter the idle position before the touchdown (even if that includes while "in" the bounce), S/B will deploy.Didn't test -900.So, what do you think??? Randy?

[Kosta 122]

I have to correct myself.Pitch for 600 was 3-4 degrees.Pitch for 700 was 1-2 degrees.And pitch for 800 was around 0 degrees.I did another test flight with 800, now I set the speed manually to lower than Vref, and guess what: no bounce, S/B deployed, very nice flare.Although, it was too slow, because pitch at G/S descend was around 6-7 degrees and it flared at one point to long. But at least NO BOUNCE!My opinion is that the Vref is for some reason not being calculcated correctly, correct me if I'm wrong please!

[Guest wee_davie_2612]

Hey Word Not Allowed,Very nice results!I've only looked at the 6 and 7 so far (basically 'cause I don't fly the 8 and 9) but I concur with your results. Even at max landing weight the 600 lands perfectly and the 700 bounces. The description of the spoiler activation is spot on aswell. The 600 pops them straight off and the 700 waits until the bounce has landed.I'll get round to doing some more tests soon.CheersDavid

[Kosta 122]

Thanks, good to know that at least someone agrees! :DAnyone else? Would be nice to get to the bottom of this.

[Guest jacaru]

I have done similar tests as Word Not Allowed with the 737-600 and the 737-700 and here are my results:737-600:VRef+5 = 130Flare: from 4

[Kosta 122]

firefox? mozilla? not using that c**p :) :) IE forever hehe... now with SP2, pretty nice.I will try a clean install of FS2004, FSUIPC that comes with an installation, without any addons, then we'll see I guess if there's any difference.

[Guest jacaru]

Now that you are at it, please try the 700 before aplying 800-900 upgrade ;)Jaime.

[Kosta 122]

Maybe I'll try 700 before the upgrade.But I'll do that tomorrow or maybe later today. Not now...

[Guest steven van leeuwen]

I also tested several times, but can't get the spoilers up on T/D. The A/T disengages 2/3 seconds after T/D and after this happened, the throttle goes IDLE, not on flare. The spoilers only deploy when manually disengage the A/T en put throttles to IDLE. It is very strange, after the first post in this topic I did one flight where the spoilers worked perfect, now they don't work anymore. Another thing I want to mention is that PMDG didn't said they solved the spoilers problem in their last update:1) PMDG 737-800/900 SERVICE UPDATE 1:==================================This Service Update is a Required Service Update for all PMDG 737-800/900 operators. As listed earlier, the following items are addressed in this Service Update:This Update addresses the following items as reported to PMDG by operators of the 737-800/900:1) Eliminates a data corruption problem that was responsible for Unplanned engine flameouts2) Eliminates a data corruption problem that was responsible for Unexplainable electrical losses (lights/radios/etc)3) Eliminates a code problem that would cause the battery to die, thus triggering electrical problems.4) Eliminates a code problem that would cause the generators to become unresponsive to the switches.5) Eliminates a code problem that would cause certain types of asynchronous behavior in the lighting system.6) Enhanced behavior for holding pattern entry.7) Enhanced behavior for holding pattern exit.8) Algorithmic track calculation for wind correction angle in holds. (Airplane "learns" during holding.)9) Corrected errors in Cost Index Model10) Corrected Generator Disconnect Switch behavior.11) Updated behavior of electrical bus switching/protection logic.12) Updated generator logic and battery behavior13) Updated fuel system behavior to eliminate potential problems with fuel imbalance14) CDU Action keys included in keyboard commands15) Eliminated SPD REF selection CTD problem16) LOC Back Course tracking fixed17) Eliminated bug that causes CTD during aircraft changes.And at last, is there someone from PMDG who has something to tell about this? I haven't see any response from you yet? I bet you know if the spoiler problem should be solved in the last update, and if it is possible to solve it anyway?Regards,Steven