Hi all,

 

I went through the initial tutorial flight on the NGX and did manage to get an autoland right once but since then, I have missed something even though I have gone thru this again in the tutorial...

 

Flying a STAR arrival procedure into a major airport for ILS approach, both nav radios tuned to the correct ILS frequency, both Course selectors set to the runway in use, Both FD's on, I intercept the localiser below the glideslope using LOC/VOR on the MCP. Aircraft stablises on the localiser and I press APP and then the second CMD button to activate dual autopilot. The aircraft intercepts the glideslope and flies the ILS approach but I have Single CH displayed and no autoland.

 

The obvious things are in place before final approach - ref speed, flap settings, gear down, spoilers armed, Autobrakes set. I have also set up the HDS on the center pedastal with landing elevation and runway length, and airfield elevation on the ovhd pressurisation panel.

 

From all this above, can you see what am I missing/not doing? I dont think it is an airfield equipment limitation?

 

Thanks!

HI Greg

 

Based on your narrative you're doing everything correctly and should be set up for the autoland.

 

Be advised:

 

The PFD will display "SINGLE CH" until aprx 1500-1400 feet AGL. At that time it will start flashing while it's performing the self check for the autoland capability. SINGLE CH will transition to "LAND 3" on the PFD along with "rollout" and "flare" armed in white. Flare will activate around 50ft and rollout at about 20ft and should track the runway centerline without a problem.

 

What approach are you attempting that you're having issues with?

Decision height?

then the second CMD button to activate dual autopilot.

 

So are both light illuminated? Then wait for 1500' - 500' RA. If you got fail-operational autopilot installed then everything will be like Paul descripted.

Different things happen depending on what system you use. Honeywell/Collins Fail Passive/Fail Operational The Honeywell system (Fail passive) at about 1500 switches to CMD and not LAND 3 I believe. The Collins fail op system goes to land 3.

 

I tend to use the honeywell system. For some reason I prefer the look and colours of it. Even if the system seems flakey at times.

 

Regards

What approach are you attempting that you're having issues with?

 

This is on FAJS [Johannesburg] Rwy 03R.

 

I do have the 737 configured with the Collins MCP, analogue sby instruments and the FAIL PASSIVE autoland.

 

I went with Fail Passive as it otherwise seems to force the glass standby instruments if you select Fail Operational. Could this be the problem?

 

Not sure if I set a decision height, but it was probably at a default 200 feet.

Fail-passive and fail-op at 500' to 1500' RA revert SINGLE CH to CMD and LAND3/LAND2 respectively if everything working and set-up correctly.

Fail-op uses ISFD and Collins MCP. Everything you described is ok.

And it doesn't matter whether DH is set or not, but for realism you should check the charts for it. For non-precision approaches and CAT I you set barometric MDA/DA and for CATII/CATIII you set radio altimeter DH/AH.

 

And my question again: does both CMD A and CMD lights lit? Or it's the same as here?

Definitely both CMD lights light up on the MCP. I have changed my config to the Fail Operational system and now I seem to get Autoland [LAND3] with no problem. I will stick with this for a while and see how it goes.