LPPT approach fun

[Jeroen Hoppenbrouwers]

Lisbon airport for a while now has been using an intermediate approach technique that is nice to see. Instead of eyeballing planes by an experienced controller who shoots the approaches, they send each arrival on a long arc around a centerpoint (near Caparica). On the arc everybody flies safe altitudes and probably about the same speed. Once the required approach separation has been achieved on the arc, the planes are called in to the centerpoint one by one at the same speed. This allows for very precise timing of arrivals on the single runway.

Only "modern" FMCs allow to fly such an arc on autopilot, so this is a relatively new technique.

https://www.flightaware.com/live/airport/LPPT

I'm not claiming this is unique to LPPT but this is the first where I see it in operation. I think LAX had something similar for Westbound arrivals already a long time ago, but then without the explicit arc being flown by the planes?


Hoppie

[macroflight]

I think this is called "point merge" - https://www.eurocontrol.int/concept/point-merge

I thought it was very common, but my frequent simulator flights to Oslo and Lisbon might have skewed my perception.

As far as I can tell, most (all?) such STARS use short straight line segments between the points in the "arc", not an actual arc. So they are probably usable for all RNAV capable aircraft.

Example: ENGM/ESEBA 4L

[Jeroen Hoppenbrouwers]

I'm obviously behind my operational awareness... that is what you get when you don't "fly" any more...

[Bluestar]

This is a common approach for RJAA for arrivals from the east. 

[macroflight]

Oooh, here's an interesting variant: WMKK (e.g GUPTA 1G) has two one-way arcs in different directions a small distance apart and with traffic in one direction limited to at-or-above FL180 and in the other direction limited to at-or-below FL170.

Most of the point merge STARS around the world seems to use a fixed altitude restriction from the beginning to the end of the arc, so regardless of where on the arc you are when cleared direct to the merge point, you will not be way too high due to letting VNAV do the thinking for you.

But there are some exceptions, e.g ZHHH PONUD 2P only has at or above restrictions, so I suspect descending in VNAV there could give you a nasty surprise if ATC clears you to the merge point early. Someone should flight test that.