No Flight Director when onside autopilot is in control - behaviour in autoland

[John H Watson]

I assume the APP light being illuminated is the only condition to allow the other A/P's to be armed. It's already illuminated when LOC and G/S are just armed, and not engaged yet.

I spent an hour or so on YouTube for 767 videos but found no clues on requirements... You can see the variations though... i.e. the 3 switches in CMD with APP selected, the one switch in CMD type with APP selected and the paddle type. On the "one switch in CMD" type, all the semi-manual approaches seem to be done with only one CMD switch selected.  i.e. they are not expecting to do an Autoland, so one A/P is sufficient for the ILS.

[United744]

APP is required to be armed only for multiple CMD engagement (assuming all other criteria for LAND 2 or 3 are met). The first engaged CMD is used for go around.

If the condition NO AUTOLAND exists, the additionally armed CMD will disengage.

NO LAND 2 or NO LAND 3 will annunciate if the conditions do not exist, but it will still allow a dual or triple channel approach.

If an autopilot channel has failed, it can't be armed. If two channels are engaged and everything is otherwise operating normally, LAND 2 will be annunciated.

This is just from memory - I'll dig out my manuals later.

[Hardy Heinlin]

If the option with the manual multichannel engagement is installed:

Once you arm a CMD (A/P) above 1500 ft, you cannot disarm it by a second push of that same CMD switch, correct? I mean when G/S is just armed but not engaged yet. (Of course, when G/S is engaged, the usual LOC/G/S disconnect rule is valid anyway.)

By the way, if you engage the three CMDs one by one below 1500 ft, you need to do these three pushes within 2 seconds, or else you will get a NO AUTOLAND or a NO LAND 3 caution. Or just push all three switches at once with three fingers if you have a hardware MCP. Well, not a problem anyway if you arm them above 1500 ft.


|-|ardy

[Hardy Heinlin]

The option "manual multichannel engagement" and that special removal of the FD during autoland are now available in PSX version 10.1.1:

http://aerowinx.com/board/index.php?topic=4020.0


Regards,

|-|ardy

[Sylle]

Hi |-|ardy,

Just tried beta14.

Two small observations:
- FD's are still displayed during multichannel approach below 1500ft AGL with the option 'no FD if AP on same source' selected on. Ticking and unticking this checkbox during the approach of the default.situ doesn't seem to change the FD behaviour?

- Once a model with the option 'manual ap engagement for multi-channel approach' has been loaded it sticks after loading one of the older model files (which do not contain this specific pin point programming in the file).
Any chance to force PSX to use the 'automatic autopilot engagement when pushing APP' (most commonly seen on 744s) every time a model is loaded that does not specifically contain this pin point setting in the .model file?

Regards,
Sylvain

[Hardy Heinlin]

Hi Sylvain,

1. Looks like I made a last-minute change that re-introduced the old behaviour.

2. This is not possible and also affects other new options introduced in the past two years. They all use the same bitmask variable (pin programming #2). It would be just as confusing if I made a default setting for all those new options (as there is no default really). But I will make a complete set of updated situ files that will replace all the situ files from the PSX DVD. This is also necessary because the nav database has changed over the years.


Regards,

|-|ardy

[Hardy Heinlin]

The removal of the FD during autoland is now fixed again in PSX version 10.1.1-beta15:

http://aerowinx.com/board/index.php?topic=4020.0


Regards,

|-|ardy