Originally Posted by Say again s l o w l y
Does anyone know of curving approaches using PAPI's or if they can even be used like this? Could they be offset to give a wider "view"?
For example were PAPI's used at Kai Tak?
There were three approaches on my company's network in the 90's involving curved approaches and, oddly enough, they were all leading to a runway 13. Kai Tak was the most prominent, the second the Carnarsie (CRI) approach to the 13L/R at JFK and lastly the visual approach to 13 at Seychelles Mahé (SEZ).
With regard to the VASIs (forerunners of PAPIs) at Kai Tak, I seem to remember there was a caution not to use them until lined up on the final approach path (135ºM) - this is not to say however that they might not have been offset slightly towards the IGS "localiser". For those unfamiliar with the IGS, the inbound path was 088ºM, thereby offset by 47º from the runway centreline, (135ºM). If not visual on the IGS slope by the MM (2.2dme) then go-around was mandatory. This involved a right climbing turn to establish on the 135ºM inbound to TH (Tathong) VOR, at something like 4500' - then start again! If visual at the MM, the checkerboard would be seen ahead (on Lion Rock?) and the lead-in strobes would normally be seen, starting at the West coast of Kowloon and curving round towards the runway threshold. In misty conditions or at night the strobes could be dazzling and could be switched off at pilot request. The runway threshold for 13 was inset to give increased clearance over the washing lines in Kowloon below (!) and the VASIs were positioned appropriately. Tactics for this final turn varied but I favoured being slightly high and slightly left of the slope at the MM, which gave a much more leisurely right turn to the runway. I never tired of this great approach.
The approach to 13L & 13R via Carnarsie (CRI) VOR is also a visual curved approach. I cannot recall the setting of any VASIs but, as there is also a published straight-in approach to these runways, I doubt there would be any offset - but I stand to be corrected. Incidentally, it is worth noting that this approach was certainly the most challenging of the JFK approaches and it always seemed to be used in the most marginal conditions of visibility, cloudbase or crosswind!
The other curved approach was to 13 at Seychelles. Originally, we used to approach straight-in over the hills from the NW (SA 4000') but, following the installation of the Game Park Warning System (GPWS) this became verboten. I recall this followed a visual circuit until passing St Ann's island, then a turn on to left base before intercepting the offset inbound radial to the VOR on the field. I cannot recall VASIs but I expect they were there - and probably would have been offset the few degrees necessary toward the final approach path. It was an interesting approach at night - especially when the proximity of the rising ground was revealed the following morning!
Ah, happy memories ... !
JD
