So I am re learning to program the CDU. I am doing ok but I have a couple issues and I am sure it is because I am missing something when I program it. All works well until I am in decent. My V Speeds go away and the Auto Throttle is hunting. So what am I missing here?
Hi Bob,
Couple of things to try;
-Do you have a STAR and arrival runway programmed in
-No discontinuities in the LEGS page
-On the PREF page, selected flaps/vref speed (Flaps 30 normal landing)
- Is there a speed / altitude restriction somewhere in the profile
Also, are you descending in VNAV?
What mode is displayed on the PFD? VNAV speed, or VNAV PROF
Note: I don't use PM so I'm not sure what differences it may have.
Thanks for the reply Kyle. I am not using VNav I am using LVL CNG. You may have hit on the flaps setting in the pref page. I will take a look as I am getting ready to work on the sim now.
Ok, so with LVL CH, the FMC should have nothing to do with it.
For a descent it should be setting the thrust to idle, and pitching for the speed set in the MCP.
And you are right. During decent everything works as it should it is when I go to APP mode that the trouble starts. I may still have a setting wrong. Been a long time since I set any of this up.
Ah ok, that makes more sense about the throttles hunting.
Make sure you make a clean ils intercept:
- Angle to runway heading less than 30ยบ and below the glide slope and in level flight
- Should be slowed such that you can extend flaps 5 before turning to intercept the localizer
- press the LOC button first, once you've captured the localizer (shows LOC on the PFD) then select APP mode
- once the ILS triangle is halfway between the top of the scale and on glide slope, select approach speed (Vref + 5), flaps 15 and gear down
- once the aircraft has slowed to below the MAX flaps 30 speed, select flaps 30.