737 800NG Bounce

[avick]

This is my first post here and as I am not a real world pilot I figure I should outline my position.
I am using Microsoft Flight simulator with the PMDG 737-800NG software.
It’s an excellent bit of kit but the problem outlined below happens on almost every landing. I have been informed by a Pilot that it’s known for this but he is not flying the 800NG (Not yet anyway). He has been told this by pals that it is not uncommon in this type of aircraft.

I have spent some time learning this aircraft and its system but can’t get a clear answer to this problem.

Can anyone tell me if the 737-800NG has a reputation for giving a gentle bounce on touchdown when using the full auto land and flaps 40.

I also tried landing with flaps 30 but still get the same bounce regardless of conditions.

The only way I can avoid this “bounce” is to disengage the auto pilot and manually land the aircraft. This takes me much further down the runway then expected.

Thank you in anticipation!!

Alan

[ifleeplanes]

Nope sorry, I havnt know it to bounce!

[XPMorten]

The MSFS flightmodel physics is not very good.
If you want a better flight model, try X-Plane.

Cheers,

M

[avick]

Nope sorry, I havnt know it to bounce!

Any ideas as to how I can stop this!!

The MSFS flightmodel physics is not very good.

The PMDG 800 is not the same as the MSFS. After flying the PMDG you can realy see how far out MS is. PMDG is very complex, the main reason why most people don't like it and the one reason I do.

[+'ve ROC]

do you ensure that your V speed is the same as per calculated on the INIT REF screen on the FMC?

As well as that, you have to make sure both CMD A and B are active for the full autoland / flare to work

Autothrottle should disengage upon touchdown.

[avick]

Yes.
I have the V speed set correctly. Even tried it with V speed +5 to see what would happen but still the same.

The bounce is not very pronounced. More a case of the main gear touching the RW then lifting slightly before it settles down.

Both command A&B enabled and ILS established and confirmed with the green CMD in the EFIS.

Everything else is working perfectly after that A/T off / Spoilers / FMC end of route tone and message in the scratch pad.

[+'ve ROC]

I really dont know, I use the pmdg model for full autolands and i've never had the problem of a bouncing a/c.

If you flare / approach at above the V speed you dont get a smooth landing (obviously)!

using the correct v spd / flaps/ autobrake though it shouldnt happen.

are your weights / loadouts correct?

P.M me if u want further PMDG advice

[avick]

Hi
In relation to my problem,

The reason I put the post up in relation to the PMDG 800NG is due to the fact that I have tried the full auto land in the 6-700 and they work fine with no bounce. I figured the makers of the software tried to recreate the dynamics of the aircraft as closely as possible.

I also remember that PMDG 737 series got a glowing report from Boeing but for the life of me I can’t remember where I seen this report. Something about an 85% - 90% accuracies.

I have spent some time learning this aircraft (737-800) and its systems. So much so that I fly nothing else in the simulator.

Most of my information came from pilots who give me feedback on the aircraft and what I should be doing to get it as close to the real thing as possible. On more then one occasion I have heard from pilots that it is not uncommon for the aircraft to bounce on landing when using the full auto land. Not a big bounce, more a case of the main gear lifting up again until the aircraft settles down.

I decided to take a trip out to Dublin Airport and have a look for myself. As I watched a number of Ryanair 800’s coming in (11 in total) 8 of them had two puffs of smoke from the main gear. I was standing in a position that I could see the undercarriage.

8 out of 11 as far as I am concerned would be considered to be above average. As for the others it was hard to tell if it was a single or double main gear touch.

This did not seem to have any visible effect on the aircraft, more like going over a bump in the road.

I hope this gives you some idea as to where I am coming from.

PS do you fly aircraft for a living??

Sorry, that was ment for PM. Wrong Btn

[avick]

Thanks Shamrock
The profile I set is as follows.

737-800
about 3500K to 4000K fuel on landing
5000K PAX
Duel ILS
Flaps 40
Ref speed exactly
Autobreak 1
Spoilers armed

You won't notice it out the window but more in the sound!!

[bantios]

I am not too sure how accurate flight sim is, but speaking of the real world I could give you some advice.

The NG series is much more aerodynamic than the classics. They are harder to slow down than the classics. This bounce could be caused by a too fast approach speed. You should be aiming at anywhere between 120-140 kts IAS depending on weight.

Make sure you have spoilers on touch-down. Flaps 40 gives the plane more lift which tends to give it a higher nose up attitude during the flare, resulting in this bounce that you are talking about. If you aren't using a short runway, try flaps 30.

Good luck champ.
If you were in OZ, id take you on a real sim.

[avick]

I will give the autobreak 3 a go and see how I get on.

Will also report back hen I do!!

Thanks

Thanks Bantios.

Most of the runways I am landing on are between 7000 and 8000 feet. More then enough room for the 800NG. A flap 30 setting would not be a big problem considering the RW length involved.

The Aero dynamics of this aircraft are impressive to say the least. I no longer allow the VNAV to control my descent as it can cause a big increase in speed. (Not what you want when you are passing 10000) What I now do is LVL CHG down to 24000 at 0.80 level off and reduce to 0.65 or 290Kts down to 11000 reduce to 240 down to 4000. 160 passing OM Flaps 15 then set landing speed and configuration. This gives me about 1 mile to go where I am just sitting monitoring everything.

I find it’s the best way to get the thing down. For me anyway.

If you were in OZ, id take you on a real sim.
If only. :D

[avick]

Looks very good but the 737-800NG is for me. the 800NG is a good all round general aircraft for short hops or mid range flights.

had my eye on a nice A320 software pack but that can wait.
;)

[avick]

Good, Not the answer you want to hear but the one I wanted.
It was getting to the point where I was about to start throwing PAX overboard to get my weight down. ;)

Now to find a way around this problem.


By the way. You asked do I fly online with Vatsim. The answer is yes almost all the time.
Sorry I did not answer this question before Shane.

[avick]

I'm normaly on line Saturday Evening