Without VTF, the GPS will activate the relevant leg
Won't the GPS always activate (change to magenta colour) the nearest leg?
So if you don't have a VTF option then you just remain in the HDG mode until you are close to the final approach track line and it should turn magenta and then you press NAV.
I hope this makes sense.
I suppose a VTF facility gives you a much longer extended centreline, but should/would ATC ever give you an intercept onto the extended centreline which is so far out that it would be outside the original T-shape? Normally ATC give you an intercept which is too close rather than too far away.
there is a dogleg at PETIT (the final approach fix).
Would ATC ever vector you onto the extended centreline outside PETID (i.e. > 7.6nm away from the airport)?
If they would, are they working off some other chart which is unpublished?
@what next
....Sometimes they will also vector you to a point "inside" of the FAF at a lower altitude. Before they are allowed to do that, they have to ask you first if you can accept an X mile final.
Might I expect, in Europe, to be offered vectoring (with corresponding descents to "MVAs") to intercept a published RNAV(GNSS but not LPV) approach at the point past the Final Approach Fix?
No, they won't, because it will screw up the automatic GPS downscaling from 1NM to 0,3NM.
Shorty approaches (6 miles final) are usually offered on ILS approaches only. BTW, I have never been offered a shorty ILS outside Germany.
Can one manually change the scale to 0.3nm on a Garmin box?
You can on a KLN.
Incidentally, can one autopilot-intercept an LPV in both LNAV and VNAV after flying more or less onto it by hand? With ILS, this is highly system dependent.
Why can't one get a "short" approach (vectors to a point inside the FAF) with LPV? Surely the GPS doesn't care what altitude you are at when heading for the airport?
Shorty approaches (6 miles final) are usually offered on ILS approaches only.
You are probably right here, I start confusing things... Our stupid stone-age (or maybe bronze age) FMS only knows RNAV approaches so whatever approach we fly, we have to call up an RNAV approach otherwise we will see nothing on our navigation display.
No, they won't, because it will screw up the automatic GPS downscaling from 1NM to 0,3NM.
I am relieved to hear that,
because, in my opinion, consequences of such vectoring practices for non-precision let-downs could "screw up" MORE than just "the automatic downscaling" of GPS displays!
Incidentally, can one autopilot-intercept an LPV in both LNAV and VNAV after flying more or less onto it by hand? With ILS, this is highly system dependent.
If you mean can you activate the autopilot when almost on the approach laterally and vertically then the answer is yes. Will obviously depend on the autopilot parameters for capture but the GPS doesn't know whether the approach is being autopilot or hand-flown. No different in that regard than an ILS.
I am relieved to hear that, because, in my opinion, consequences of such vectoring practices for non-precision let-downs could "screw up" MORE than just "the automatic downscaling" of GPS displays!
Not just non-precision. In some ways I like the GPS preventing ad-hoc approach activation. Prevents temptation to cut corners ie a short final which can happen with ILS and other ground based approaches.
Why can't one get a "short" approach (vectors to a point inside the FAF) with LPV?
During approaches that provide continued vertical guidance (not just "an advice" as in +VNAV mode) such "shortenings" could sometimes be acceptable, although I prefer to stick to a pre-planned and better rehearsed "routines" :)
During let-downs without continued vertical guidance, confirming one's alttitude while passing over FAF is mandatory.
During let-downs without continued vertical guidance, confirming one's altitude while passing over FAF is mandatory.
Yes, although (while I wouldn't advocate it) the difference with a GPS approach is that you know more easily where you are ie on the final approach segment after the FAF and before the MAPT. With that knowledge you could safely descend to the MDA. Compare that to an NDB or VOR without DME.
