737 VOR/LOC button for VOR approach (both FMC fail)
Good afternoon everyone!
I would be so grateful if someone could explain me one moment with Boeing 737:
imagine we have both FMS fail so we need to revert to conventional navigation. We navigate via VOR and during flying SID (or any other route via VOR) we can use VOR/LOC so autopilot can maintain our preset radial. Right?
And now goes the questions: we start the VOR approach for runway with no FMC (only raw data).
1. Do we need to set to the same active freq on NAV1 and NAV2 for VOR we use for approach (for me it’s strange, we can choose VOR2 on EFIS)?
2. I found nothing in FCTM connected with VOR approach using raw data. The only recommendation for non-precision approach is to use the HED SEL or LNAV to maintain the radial, but why can’t we use VOR/LOC? It seems much easier. I noticed that Boeing has no recommendations to use VOR/LOC for VOR approach. Yeah, usually we have FMC so we only check the VOR needles and the route is set in FMC, but in case of FMC failures we don’t have all of this.
do I understand something wrong?