Another LAND 3 Problem

[HenkA 0]

Hello everyone,A lot of posts and threads have been written about this. Searched for it, but did not find my problem.I want to make an autolanding at LSZH rwy 14 (CATIII). Both NAV's set at 108.30. Both courses set at 136 degrees. After having intercepted the localizer (VOR/LOC activated), a few moments later, I see the glidescope (open) diamond. After the glidescope is intercepted (filled diamond), I switch on the second AP, and as soon as the 737 is going down, following the glide-path, I get Single CH into the PFD. At approx. 1500 feet AGL, the self-test is carried out, and the Single CH changes into LAND 3.What I really don't understand is that I get the announcement Single CH. In my opinion it should be CMD or FD.What am I doing wrong?Thanks for feedback.RegardsHenk Altena

[Fabo 213]

Nothing. The indication in APP mode differs between SINGLE CH and CMD/LAND 3 depending whether one AP is coupled or both. Second AP is actually coupled after a self-test, somewhere in 1300 AAL range.

[Veracity 8]

That's correct behavior. The PFD will display "Single CH" until 1500 feet and then LAND 3 with rollout and flare armed in white.

[HenkA 0]

Thanks very much for the quick answer. Tutorial 1 tells me however that before LAND is displayed, i.e before the self-test, the PFD should display FD. That's what puzzles me.Henk

[Fabo 213]

That sounds strange. FD is indicator of Flight Director mode e.g. no AP s engaged, but FD are shown for reference.