Originally Posted by
Airbubba
Thanks for taking a look, is it coded flyover in the FMS or on the chart in the tablet? Do you have RF capability in all of your Triples? Is your database in error perhaps? I found a miscoded constraint on a SID the hard way a few years ago.
As
bekoblokage said:
The chart linked on the Hong Kong Aerodromes site definitely has PORPA charted as a fly-by waypoint:
http://www.hkatc.gov.hk/HK_AIP/AIP/A...RASSE%20EF.pdf
The Hong Kong AIS bulletin announcing publication of the RASSE 1E and the other RF noise mitigating SID's has this:
http://www.hkatc.gov.hk/HK_AIP/supp/A19-11.pdf
That is indeed what the book says. From the pub linked above:
And that is my point; has this ‘agreement’ with the company been fully thought through in respect of the possibility that another operator using the CX callsign will be given the RF SID unexpectedly?
I found a miscoded constraint on a SID the hard way a few years ago.
That is why it is good procedure design/charting practice these days (not an ICAO requrement tho I don't think) to include the correct FMS coding, as the procedure designer intended, on the back of the chart (2nd page in the PDF). In the past it was left up to the FMS encoders to interpret what they thought the designer wanted the aircraft to do purely from the chart. Often Direct to Fix or Course to Fix were confused or fly-over/fly-by were not clear.
Even ignoring the PORPA symbol on the chart, you will see that the correct coding in the table on page 2 is Fly-by in the RF procedure. If Monarch Man's 777 really does show fly over, then their encoders have done it incorrectly.
As an aside, as the original AIP SUP noted, the nominal tracks for the RF SID "mainly" overlay the normal RNAV SID but there are subtle differences. The nominal track for the normal RNAV will make allowance for the along-track error of the PORPA fix and the roll in time and radius based on 15 degrees AOB.
On the other hand, the RF is basing that turn purely on a radius from a centre (as in the coding table) and the RF-capable FMS will automatically determine the roll-in point and bank angle to make good the arc, whether or not it has "reached" PORPA. Hence why it needs to be fly-by.
When flight testing it in the sim in OEI conditions it was a little unnerving for crews who were used to the normal roll-in point relative to the terrain on the right compared to the earlier roll-in of the RF, despite they both provide the same obstacle clearance. [ Before I get jumped on, I should clarify that PAN-OPS obstacle clearance presumes normal operations. The sim trials on OEI were for contingency planning only.]