Missed approach

[VIPERGTSR01 22]

Yesterday I was practicing some missed approaches / Go-arounds with the NGX and FS2Crew and had a small issue

 

I would call missed, press TOGA and throttle advance (then also re-armed A/T), asked flaps 15 and followed the flight director, asked gear up, asked FSCrew for heading select which went fine but when I asked for VNAV it would arm VNAV but it would dis-arm the heading select. I asked for command A and I would have to manually re select heading select (was runway heading).

 

I ended up trying it with LNAV which armed but when I asked for VNAV the LNAV disarmed and heading select armed instead and VNAV didn't arm.. I actually did 10 loops of go arounds one after the other and to my suprise one of them (around attempt 7) armed both heading select and VNAV as I requested. But I can't replicate it.

 

One thing that confuses me is why Heading select should be effected when VNAV is being amed and why Heading select replaced LNAV when VNAV was being supposed to be armed but didn't. This is what makes me think maybe there is some "wires crossed" in the background or am I doing something wrong?

[byork 2,259]

I'll pass the mic over to Damien.

 

That sounds some some logic issue in the NGX autopilot itself... it could be the way it is in the real unit or it could be a bug in the NGX itself.

 

Cheers,

[damienw 1]

Yesterday I was practicing some missed approaches / Go-arounds with the NGX and FS2Crew and had a small issue

 

I would call missed, press TOGA and throttle advance (then also re-armed A/T), asked flaps 15 and followed the flight director, asked gear up, asked FSCrew for heading select which went fine but when I asked for VNAV it would arm VNAV but it would dis-arm the heading select. I asked for command A and I would have to manually re select heading select (was runway heading).

 

I ended up trying it with LNAV which armed but when I asked for VNAV the LNAV disarmed and heading select armed instead and VNAV didn't arm.. I actually did 10 loops of go arounds one after the other and to my suprise one of them (around attempt 7) armed both heading select and VNAV as I requested. But I can't replicate it.

 

One thing that confuses me is why Heading select should be effected when VNAV is being amed and why Heading select replaced LNAV when VNAV was being supposed to be armed but didn't. This is what makes me think maybe there is some "wires crossed" in the background or am I doing something wrong?

 

Hi Jay,

 

Try this exactly as I tell you and we'll go from there.

 

 

Initiation

• Push TO/GA, flaps 15

• Verify go-around attitude

• Verify or adjust thrust as needed

• Positive rate of climb - gear up

 

 

Above 400 feet RA

• Verify LNAV or select roll mode

• Verify missed approach altitude set

• Verify route tracking

 

 

Acceleration height

• Retract flaps on schedule

 

 

After planned flaps set and at or above flap maneuver speed

• Select LVL CHG or VNAV

• Verify climb thrust

• Verify altitude capture

• Do the After Takeoff checklist

 

Some notes for you:

 

1) Pitch and roll modes cannot be engaged until above 400 feet AGL

2) When the flaps are retracted to the desired position and the airspeed approaches maneuver speed, select LVL CHG and ensure climb thrust is set.

3) If VNAV is used during go-around, the FMC missed approach profile should contain the appropriate holding speeds and altitudes.

4) For a manual go-around:

 

• rotate manually

• select or verify go-around thrust

• engage autopilot as needed

 

Let us know how it goes.

 

Regards

[VIPERGTSR01 22]

Thanks for the response guys, it is late here in Australia so I will follow those instructions tommorrow closely (though it seems I have been pretty much) and see how it goes after a bunch of attempts and report back with my results.

 

Just as a note I have never had a issue enabling any modes manually but just when I ask FS2Crew to do it it strange things have happened, I will do a with and without the help of FS2Crew. :)

[VIPERGTSR01 22]

Ok so I did a few go arounds following Damiens instructions exactly and the problem persists, however, I did go arounds with both FS2Crew and without and it happens without FS2Crew also so it is obviously a NGX thing.

 

When I select a vertical mode (VNAV or LVL CHG) after heading select or LNAV it always disengages/disarms the lateral mode (even with a fair time between selecting modes) and I have to re select it again. I have been selecting Lateral modes at about 800-1000 RA and vertical modes another 500 or so further on. As I said it happens with or without FS2Crew so it isn't a FS2Crew issue, thanks for the assistance guys :)

[skysurfer 76]

Hi Jay. Gues what, I have the same issues. I tryied all suggested steps but it did not work right. I even asked pilots at work maybe they could explain this, and they said that my NG was not save plane to fly. Have you posted this in PMDG forum yet?

[VIPERGTSR01 22]

Thanks for the response Ed, It's nice to have confirmation it isn't just me (not that I wish others to have the problem). No I never ended up posting it on the PMDG, you can if you wish and I will report my findings there also.

 

I am kinda suprised this problem hasn't been reported before (from what I am aware) I guess go arounds isn't too commonly done by flight simmers.

[skysurfer 76]

I will go ahead and practice again and see what it does. If no changes, I will post it in PMDG.

Thx