FMC VOR Auto/Route Tuning Behavior

[John H Watson]

Yes, understood.. I've already corrected my previous statement I think it was because they mentioned it at all that confused me. Why wouldn't it be simultaneous? Two radios, two slots.

Going back to my earlier Sydney example where I had deliberately programmed a route from London with a Heathrow SID... and the CDU Nav Rad page displayed Procedure and Route tuned stations in the left and right slots (respectively) applicable to Heathrow. I can't seem to find a solution on the flow chart. What would happen if, say, the aircraft was in the air and within range of a usable single DME station pair in the Sydney region. What should the displays look like (CDU and ND).

[Hardy Heinlin]

IRS aligned?

[John H Watson]

Too long ago to remember...

Procedure + Route Tune

Here's a Procedure tune plus manual tune (perhaps not on the same day.... different lighting). The radial is shown. I assume radials are only available with the IRUs aligned.

Procedure + Manual Tune

I did manage to find a short video showing identical stations autotuned. I remember systematically inhibiting regional stations, but it took some effort to get this result (I can't remember exactly how I achieved it). I don't think it comes naturally to the FMC. It may have been discussed during beta testing, but I can't find the message threads. The aircraft was on the ground and probably in the cone of confusion, too.

Video here:

Identical autotuned stations

[John H Watson]

Here's a combination I used to see in Sydney quite often...

Autotuned VOR-DME and Tacan

Bindook (BIK) and Richmond TACAN (RIC) were autotuned. Even though you can manually type RIC in the scratchpad and line select it successfully to the Right VOR, the station won't appear in the slot if you just let the aircraft autotune normally. I didn't have the Left VOR switch on, so you can't see the station (BIK) in the bottom left hand corner of the display (but is shown as a green icon on the display).