May 17, 200224 yr Rob, to be fair to people, the 737-400 (as modeled by DF) can track a VOR using VOR/LOC. Just because they are asking doesn't mean they are only flying default MS aircraft. I know I was initially surprised a 767 couldn't do what an older 737 could do. I wonder why Boeing removed this capability.Lee Hetherington (KBOS)
May 17, 200224 yr You are correct, the DF734 does have that feature, but the question is generally posed by people making the big "leap". I should not assume, however, that they have only used MS default.Maybe Ian or a pilot can comment as to why Boeing removed that feature....I am guessing the VOR/LOC feature became redundant with the FMC being able to handle the intercept.Rob.
May 17, 200224 yr You might be right. The DF 734 FMC can also handle the intercept as well.Lee Hetherington (KBOS)
May 18, 200224 yr >Maybe Ian or a pilot can comment as to why Boeing removed >that feature....I haven't been given any official notification, Rob, but I'd imagine that the FMC can track a pseudo(artificial)-VOR radial using LNAV more accurately than it can a real VOR radial in VORLOC mode. With the advent of GPS and DME-DME updating, a better postion fix is possible than one achieved by simply tracking a wobbly ol' VOR radio signal. As previously mentioned on this site, even ILS tracking no longer relies solely on the aircraft gliding down a pure radio beam (which may drop in and out or be deflected by passing traffic). A psuedo glidepath is generated within the autopilot computer ...and the aircraft glides down this, with the A/P constantly comparing the pseudo slope with incoming radio signals (to make sure the two don't vary for too long a period).Even with the VOR groundstation out of commission, the airplane can still follow that imaginary radial (It's easy to see the advantages in this case ;-)).Cheers.Ian.
May 18, 200224 yr Makes perfect since to me and very well said, as always. Thanks for jumping in here and offering a professional view.
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