YPPH RNAV 21

[haughtney1]

Done a couple of these approaches over the past week or two, and with both of them it seemed to me that there is a bit of an offset to the west of the centreline.
Both times RNP was 0.11 actual was 0.05, so I'm wondering if it's a known thing in YPPH, or maybe a coding thing?
Both times I checked and re-checked, and both times it was on 777's with less than 1000hrs on each airframe.
All you PER based guys got any ideas? or seen anything similar?

[avconnection]

There is 1 degree difference between runway direction and the final approach course, which is listed on the charts. Would this account for it, or is it a great difference?

I'd be more interested to know, why so many Perth based operators are opting for the VOR over the RNAV or stating they're unable to accept the RNAV?

[haughtney1]

Av, yeah I guess that's probably part of it, plus after 11hrs across the Indian ocean I'm most likely a bit crossed eyed in any case :}
It just didn't seem that the final approach course was leading us directly to the threshold.....but I can accept my eyes could have been playing tricks....the glideslope was a thing of beauty...2 whites 2 reds all the way in :ok:

[clear to land]

Maybe you should have been using those 3 hrs in the CRC for zzzzz's rather than watching the latest (modified) releases on ICE ! ;)

[Aeromuz]

Maybe both pilots arent RNAV approved or the aircraft doesn't have the right gear or approval to do the approach. Thats just what we face in our fleet.

[Tankengine]

Rounding errors affect RNAV runway approaches, they are often a little offset.:8

[Capn Bloggs]

H1, what was your Flight Technical Error (CDI bar deviation)? The box/magenta line can be spot on but the autopilot may not be following it exactly/accurately enough for the eyes looking out the front.

[AerocatS2A]

haughtney1, was the other pilot offset slightly east of the centre line? :}

avconnection, I know that for one of the Perth operators, part of their fleet will fly the RNAV NPA nicely on the autopilot but the CDI isn't scaling properly on finals so you can't easily crosscheck the autopilot's tracking without looking at the xtrack on the box, and you can't accurately fly it by hand. There is a fix on the way supposedly, so hopefully you'll see more RNAV NPAs and fewer VORs.

[unseen]

Done a couple of these approaches over the past week or two, and with both of them it seemed to me that there is a bit of an offset to the west of the centreline.
Both times RNP was 0.11 actual was 0.05, so I'm wondering if it's a known thing in YPPH, or maybe a coding thing?
Both times I checked and re-checked, and both times it was on 777's with less than 1000hrs on each airframe.
All you PER based guys got any ideas? or seen anything similar?

ANP 0.05 is ~92m of possible lateral error (think i calculated that ok). How much were you offset by?

The runway at PER is closer to 195 than 196 - 1 degree is noticeable.

Was it a constant offset, ie flying parallel to centerline?

Or an angular offset, converging or diverging from centerline?

[haughtney1]

Bloggsy, it was all well within the tolerances, the FD's were not commanding any corrections.
Haha Aero...yeah probably.
Unseen it was a constant offset, it didn't appear to be converging on the threshold.
Again, don't get me wrong, at MDA it was a perfectly acceptable position from which to continue the landing, it's just not what I expected to see in terms of lateral guidance.