Non precision question regard 'arming' 'hard altitudes'

[akafrank07]

In my notes of a non precision approach flown in a b737, whenever intercepting heading you go flaps 5 and then 'arm' LNAV or VOR/LOC.

Whta does it mean by arming the LNAV or VOR/LOC, is this just the same as selecting it i.e. activating the LNAV or VOR/LOC?

Also from my notes, when one mile out you set 'MDA/hard altitude'. What would hard altitude be referring to, a step down fix?

[Denti]

Depends a bit on the specific SOPs of the airline in question.

Hower, "arming" LNAV/VORLOC is exactly that. You press the relevant button and once it intercepts the final it will become active and intercept it. Before that it is armed (white indication on the FMA).

We wouldn't do either of those things above on a non precision approach, we would simply press the APProach button which arms the FAC (final approach course) and GP (glide path, not to be confused with a glide slope). No need to set the MDA either, especially as there are no MDA's according to EU OPS anymore, its DA's now.

Anyway, on a LNAV/VORLOC non precision we would set the DA, and at 500' above that the go-around altitude. Hard Altitude would be any other hard altitude limit above DA if needed.

[akafrank07]

Thanks Denti :ok: