View Full Version : Curving approach and PAPI's.

Say again s l o w l y
30th Aug 2007, 22:21
According to CAP168 PAPI's give vertical guidance at upto 15 deg either side of the centreline.

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?

Thanks in advance.

30th Aug 2007, 22:30
FNC (Funchal), PAPIs are offset out towards the downwind position in the bay.

30th Aug 2007, 23:20
Nice (LFMN/NCE) has offset PAPI's for the SAYLEA 22R arrival.


31st Aug 2007, 06:05
Ref Kai Tak,
I can only remember turning on the lead-in lights using a constant rate of descent till I got on the PAPIs (or whatever they were!). Pls forgive the brake (brain) fade. So, cannot remember the exact parameters for the Visual Appr Aid. Perhaps a CX pilut cud answer this. It sounds like the sort of question their Wonkas would ask.

Jumbo Driver
31st Aug 2007, 10:02
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 Mah (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 (135M) - 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 088M, thereby offset by 47 from the runway centreline, (135M). 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 135M 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 ... !


31st Aug 2007, 11:45
I can remember an approach into Ponape, (Central Pacific), it was a requirement to follow a line of white lights as they curved around to the threshold, don't think it was tied in to a PAPI though, just a visual alignment with the runway. Only when one subsequently did the same approach in the daylight did the significance of following the curved line of white lights become apparent! On the right was an enormous cliff towering above the approach path!

31st Aug 2007, 14:16
approach into Ponape, (Central Pacific), it was a requirement to follow a line of white lights as they curved
What year was that? I flew into Ponape (now Pohnpei) many times during the period 1976-1988 and there were no lead-in lights then. An Air Nauru pilot reported that the Ponape DME was working in reverse on his approach which fortunately was VMC. The FAA hurriedly checked out his report and sure enough it was true. It made the DME arc a bit trickly to fly...
Warming to the subject..at Tarawa a "new" VASIS appeared but not NOTAMMED. An F28 pilot landing at TRW (Bonriki International Airport) followed the VASIS light signals and finished up very low while still showing on glide slope. More reports came in and it was obvious something was a bit fishy about the new VASIS. An inspection revealed the "VASIS" was an antiquated apparatus of two red painted pillar box structures. The local DCA admitted it had never been flight tested but that Air Pacific said that "it looked OK!"
After strong representations from Air Nauru pilots who flew 737 and 727's into Bonriki, the truth came out. Some enterprising character had sold the locals an early crop-dusting type visual system. For several months the red boxes lay slowly rusting away in the cargo shed until a visiting FAA inspector from Guam happened to call in as he had heard about this mysterious "VASIS".
His jaw dropped when he saw the light boxes in the cargo hold and he said he would like to buy them and place them in an aviation museum in USA. Eventually the bits and pieces vanished - who knows where. Maybe it suffered the same fate as war relics of the Tarawa battle in 1943 where locals used long discarded US marine Garand rifle barrels or Japanese rifles to use with cooking pots over fires.