ToGa Vnav?

[sas550]

Using the latest PmMCP, GC and CDU. When I take off I set to/ga mode and I see that HDG mode is autoselected. When I press lnav the plane keeps it hdg and neglect to follow the route until I choose vnav, flc or v/s. This can't be the right behaviour. Can someone confirm seeing this?

[Bob Reed]

It is right. When you push TOGA you activate the hdg. If you turn the hdg your ac will turn.

[Michael Carter]

Airplanes have come a long way.

The only thing the TO/GA buttons on the 727 throttle do is pitch the bat wings to the proper pitch attitude on the flight director!

[sas550]

Tnx for your answers.

It is right. When you push TOGA you activate the hdg. If you turn the hdg your ac will turn.

I can live with that but if I choose lnav during toga mode it doesn't work. I have to choose a different vertical mode before lnav kicks in. It shows lnav on the announciator but the plane doesn't follow the route. That is my problem.

[touwersl]

Hi,

Maybe an extremely stupid question; Do you engage the autopilot?
When you don't you will be in flight director mode and the aircraft will not follow the route automatically.

Regards,

[Bob Reed]

Lnav does not work from the ground.

[sas550]

Hi,

Maybe an extremely stupid question; Do you engage the autopilot?
When you don't you will be in flight director mode and the aircraft will not follow the route automatically.

No I don't activate the ap but the flight director should lead me on to the route as soon as I engage lnav. I usually engage lnav at 1000-1500ft and then it should work

[Bob Reed]

So you are not trying to get it to fly the plane, but direct you?

[sas550]

I usually hand fly the plane the first part of the departure. But the flight director is supposed to give lnav guidance when lnav is engaged but it doesn't until engaging vnav, flc or v/s. That's not logical.

[NicD]

Thats true, and most RL crews like to hand fly departures following the flight director ... often up to transition altitude. Flying would be pretty boring otherwise.

Cant check now - but I think there is a setting in the MCP.INI file that controls what mode is engaged on TOGA after liftoff.