Dual FMC failure Boeing 737 ng

[Checkboard]

I asked you how to proceed to an RNAV point raw data, not by proceeding VFR or Dead reckoning.

... and it still startles me that you think this is difficult !! I was pointing out that the IRS is available by switching the IRS panel to track mode, which will give you a very accurate track - i.e. no wind calculations!

So, to spell it out:

1. FMC fails.
2. Select HDG on the Mode Control Panel.
3. Complete QRH checklist(s).
4. Inform ATC NON-RNAV.
5. Get chart out of folder and determine current position, from last recorded fuel check on the PLOG initially then by local VOR.
6. Obtain airway track from chart and maintain that using HDG bug, aided by current track from IRS panel on the overhead (IRS position drift is irrelevant).
7. Approaching RNAV position, dial up suitable fix combination - VOR/VOR or VOR/DME.
8. As the aircraft approaches the fix, it will intercept one of the fix criteria before the other (assuming you are slightly off track) - ie one VOR radial before the other, or the DME arc before the radial. Slightly adjust the HDG bug to track the aircraft along the first intercept until you are at the second (fly the aircraft into the 'V' of the fix)*,
9. at the fix, turn HDG to next track - correct tracking using the TRACK display on the IRS panel overhead.
10. Write down time at fix. Note Groundspeed from overhead IRS panel. Calculate time to next fix (or just use the PLOG planned times - but personally I would work out my own).

The saying is that pilot's earn their larger-than-bus-driver wage not when things are going fine, but when things go wrong. Personally I would be professionally ashamed to ask for ATC help to navigate my aircraft, when no Navigation equipment on the aircraft had failed - just the box that did the navigation thinking.

*,(I was going to mention the fix-to-fix thing (although I never called it that) but thought it too complicated. Good link, though.) I would use that approaching the RNAV fix point.