On go-around, if in LNAV, ngx drops back into HDG SEL when LVL CHG selected?

[Stearmandriver 2,244]

Pretty much says it all. I've noticed that during a go-around, it'll drop out of LNAV. I'm using our company profile which is pretty standard I'm sure: TOGA, flaps 15... positive rate, gear up, set/verify missed approach altitude... at 500ft, LNAV, flaps 5... clean up on schedule. Reaching clean maneuver speed, LVL CHG. At that point, the FMA indicates MCP SPEED for a pitch mode which is correct, but roll mode also drops back to HDG SEL. Only happens on a go-around, not on takeoff.

 

Anyone else experience this? Is there a setting or option somewhere that controls this behavior?

 

Thanks...

[downscc 1,327]

Yes, roll control on go around is an option. Set up same as other aircraft settings via OC or FMS. I don't remember exact wording for the option but it's in the Introduction.

[Stearmandriver 2,244]

Hmm ok thanks I'll check it out. I thought I remembered an option for roll control on takeoff - either wings level or heading select - but I guess I missed the go-around option. Thanks..

[Stearmandriver 2,244]

Well I've searched through the menus and I can't find an option relating to roll control during a go around. Thoughts?

[tcas_climb 45]

That option is only available on the pmdg 777 I'm afraid. You just have to engage lnav again.

[bjratchf 80]

I think it might be in the equipment options of the FMS- Wings Level or HDG mode are the two choices. 

 

What caught my attention was your company procedure of level change. I wish we did that at my shop!

[Stearmandriver 2,244]

That option is only available on the pmdg 777 I'm afraid. You just have to engage lnav again.

Gotcha, thanks. Oh well, it's a minor point but maybe one to add to the bug list then. Plane should not drop out of LNAV after it's been selected like that.

[tcas_climb 45]

Gotcha, thanks. Oh well, it's a minor point but maybe one to add to the bug list then. Plane should not drop out of LNAV after it's been selected like that.

Not sure it's a bug will have to check the manuals, but as noted it's usually an option purchased by airlines.

[Driver170 42]

This is a bug

[ALF1 15]

Was this after an ILS approach or RNAV approach ? Dont take my words for gold but I did a missed approach the other day at KSFO after an ILS 28R app. And engaged LNAV at 400 ft and no problem.

 

I am going to do some more today IAC and IAN and come back.

[scandinavian13 5,192]

Gotcha, thanks. Oh well, it's a minor point but maybe one to add to the bug list then. Plane should not drop out of LNAV after it's been selected like that.

 

Do you have a reference for that?

 

 

This is a bug

 

Reference?

 

 

 

We can't simply run off chasing everything some random person in the forum says is a bug. If you know it's a bug, please provide a reference to where the simulation is not in line with the real aircraft operation so that we can verify it.

 

If it's a customer option, then it isn't a bug. It's simply a feature we didn't model, similar to how we chose to model the software version of the FMC that's in there and not some other software version.

 

Finally - as always - if you believe you have found a bug, submit it via the support site. We aren't guaranteed to check every post here.

[Driver170 42]

It was brought up on this ages ago on my old thread. And alot of members said so. Will try and look for it

[JoeDiamond 67]

I have noticed that after selecting LNAV after a go-around the lateral mode will switch to HDG SEL when the missed approach altitude is captured and the vertical mode changes to ALT CAP. It seems that whenever the vertical mode changes from TOGA to anything else it kicks the lateral mode to HDG SEL. It definitely should not act that way.

 

LNAV on go-around is a company option. Our actual airplanes will have LNAV armed during the approach and will engage LNAV automatically when you select TOGA.

[Driver170 42]

Yeh its defo not simulated properly and should never kick you out of LNAV

[scandinavian13 5,192]

References and tickets, then.