A/T Problems

[kevinh 409]

The mcp speed set to 180kt, flaps 5 allready extended, the aircraft at the alt with gs armed. At this point a/t commands about 60-70% throttle because the aircraft produces a lot of drag, so we need much power to maintain 180 kt. Then a gs comes down, when captured I put gear down and set after gear extended flaps 20. The a/t commands late to decrease the throttle (because of gs capture and negative vert speed) and the speed of decreasing thrust is slow (very big engines) so in spite of the fact I was good established on approach when captured gs the aircraft accelarates because as mentioned above everything happens to slow. So the speed increases, than after finaly the a/t set the throttle idle the aircraft is fast (210-230) so it is very very difficult to decrease the speed and get a stable approach... Any suggestions?

You don't mention changing the MCP speed from 180. When you see the G/S moving, select Flap 20, gear down and reduce MCP speed to the "20" bug on the speed tape. When speed is stablised at that set the MCP to Vref+5 and select Flap 30. You should have no trouble decelerating in this configuration. If you are accelerating to 210-230 knots on the G/S then it is something else you have done which you haven't mentioned.

 

 

By the way yesterday I flew from Amsterdam, there was very bad weather with turbulance and windshear. In climb after passing 10000 the speed bug jumped to 290 kt in order to accelerate but the aircraft remained climd on speed of 235 kt which was very very soon from amber line (before stall). The throttles were in clb mode, the vert speed was 1750 ft/min, nose angle at about 8 degrees. All the way up until good weather I holded a hand on a throttle in order to disc a/t and set full trust if the speed decreases too much. After passing bad weather (about FL250) the nose goes down to 2-3 degr and the aircraft accelerated to speed bug... Is this the way how the aircarft flies in reality?

This is a problem with FSX turbulence. The aircraft becomes very unresponsive and AP can't control it so well. FSX also overdoes turbulence effects. I have maximum turbulence set to 30% in ASN (there are three different settings, so make sure you change them all as the default is 100%). This reduces the effects to a more realistic level and gives the AP a chance to work better. Note, in the climb the A/T is controlling thrust, it's the AP which is controlling speed.

[dimatrixxx 0]

Hi,Dimitri,

 

Three questions:

1) What are ALL of the settings in ASN regarding turbulence.  There are several.

2) What was the exact time of the approach to RJAA?  ASN can be set up to recreate weather at a given date and time.  Also, do you have the METAR from ASN during your approach?

3)  What was the gross weight on approach, and which 777 were you flying -200LR or 300ER?

 

I also want to remind you again that PMDG wants you to use your full first and last name in its forums.  I am not comfortable corresponding with someone who does not follow that rule.  If you don't want to publish your full name in a forum you can file a ticket with PMDG.

 

Mike

Hey Mike,

 

1. Now I found all three settings and set them to 50 (some of them were at 100)

2. The approach was yesterday between 03:00-04:00 z. I used rwy 34L for landing. I do not have metar anymore...

3. I fly always b777-300er

 

I plan to fly today at the night, I will check how it changes after changes in ASN settings, I write the result.

 

No big secret on my name, I'm Dimitri Bespalko :-)

[pcubine 143]

No big secret on my name, I'm Dimitri Bespalko

Set it up so that is done automatically. Try this - click on your user name in upper right corner, click on My Profile, click on Edit My Profile, click on Signature, in Edit Signature enter your first and last name, click save and your name will be on all of your posts.

[dimatrixxx 0]

So guys, after flying 3 approaches I can say that now the problem seems to be solved. The solution was like before many times mentioned- to decrease turbulance settings of ASN down to 30-50. I personally set all three setting to 35 and it seems to be ok for me. Thanks for your help guys!

[Alpha Floor 237]

Glad to hear that Dimitri!

[Mike777 163]

 

 

So guys, after flying 3 approaches I can say that now the problem seems to be solved. The solution was like before many times mentioned- to decrease turbulance settings of ASN down to 30-50. I personally set all three setting to 35 and it seems to be ok for me. Thanks for your help guys!

 

Glad to hear it's resolved, Dimitri!

 

Mike