Pierre95 14 Posted January 25, 2014 Share Posted January 25, 2014 Hello, I'm facing a question concerning EROPS alternates Wx suitability period. I've built a plan over Chine to VHHH. It includes an EROPS area because China has very little airports in a few regions. Reading the EROPS Definitions, I see the alternates wx suitability period starts 1 hours before the earliest ETA to the alternates and ends 1 hours after the latest ETA to the alternates. So the time range should be at least 2 hours. In my plan, the max range is 31 min 18:41 - 19:12. Could you help me to understand this point? Thanks I attach the EROPS part of my plan. Est T/O = 10:55 Best Regards Pierre Link to comment Share on other sites More sharing options...
dougsnow 50 Posted January 25, 2014 Share Posted January 25, 2014 Pierre My airline does ETOPS along the L888 airway. The suitability times are the earliest possible arrival time at the nominated alternate, and the latest possible arrival time at the nominated alternate. For US carriers under 121, I no longer need to protect the hour before and hour after, as long as the WX in the window is at/above mins, I'm legal. Before and after the window, it can legally be W0X0F and I am not required to care. Link to comment Share on other sites More sharing options...
Pierre95 14 Posted January 26, 2014 Author Share Posted January 26, 2014 Hi Doug, I'm not sure to well understand your explanations (Sorry) could you please detail? Thanks so much Pierre Link to comment Share on other sites More sharing options...
dougsnow 50 Posted January 26, 2014 Share Posted January 26, 2014 There is an image in my ETOPS training module I wrote for work I'll bring home tomorrow which will explain it... Link to comment Share on other sites More sharing options...
Pierre95 14 Posted January 26, 2014 Author Share Posted January 26, 2014 Thanks a lot Doug Cheers Pierre Link to comment Share on other sites More sharing options...
Pierre95 14 Posted January 29, 2014 Author Share Posted January 29, 2014 There is an image in my ETOPS training module I wrote for work I'll bring home tomorrow which will explain it... Hi Doug, Any news about this? Thanks Cheers Pierre Link to comment Share on other sites More sharing options...
dougsnow 50 Posted January 30, 2014 Share Posted January 30, 2014 Ive just been super busy at work with recurrent training - will have it tomorrow Link to comment Share on other sites More sharing options...
Pierre95 14 Posted January 31, 2014 Author Share Posted January 31, 2014 Ive just been super busy at work with recurrent training - will have it tomorrow Thanks so much. Kind Regards Pierre Link to comment Share on other sites More sharing options...
Pierre95 14 Posted February 5, 2014 Author Share Posted February 5, 2014 Hi, Any news Doug? Cheers Pierre Link to comment Share on other sites More sharing options...
belisar 126 Posted February 7, 2014 Share Posted February 7, 2014 Hello Pierre! Let's take airport XXZZ suitability time into consideration. Earliest time of arrival would probably be your time diverting from ETP1 to XXZZ via A. Latest time of arrival, would be you getting to ETP2, then having to divert and get back to XXZZ, thus B+C. That's what I think the logic behind that is. Kind regards, Belisar Link to comment Share on other sites More sharing options...
Pierre95 14 Posted February 8, 2014 Author Share Posted February 8, 2014 Thanks so much Belisar, Your explanation is perfect but I saw JAR OPS includes 1 hour before earliest time of arrival and 1 hour after latest time of arrival. It should be interesting to have a setting in aircraft ETOPS configuration able to doing that. Best Regards Pierre Link to comment Share on other sites More sharing options...
belisar 126 Posted February 8, 2014 Share Posted February 8, 2014 It will very interesting to get to know the exact mechanism of how it is working if PFPX. From a calculation, the latest possible time to ZWWW would be getting there from the ETP, Departure at: 10:55 Scenario 1 Time over ETP: 10:55+07:13=18:08 Time to divert to ZWWW: 00:57 ETA ZWWW 18:08+00:57=19:05 Scenario 2 Time over ETP: 10:55+07:17=18:12 Time to divert to ZWWW: 01:15 ETA ZWWW 18:12+01:15=19:27 PFPX gives 19:12 latest. There is probably something I am missing there as well probably having to do with the rather short segment. Kind regards, Belisar Link to comment Share on other sites More sharing options...
dougsnow 50 Posted February 8, 2014 Share Posted February 8, 2014 The calculation isnt from the ETP, its from the ETOPS Entry Point (or Exit Pt), so earliest arrival is from the ETOPS Entry Point back to the divert field, or the latest arrival is from the exit point, and so on. I had to travel for work this past week, and it has been crazy Link to comment Share on other sites More sharing options...
belisar 126 Posted February 8, 2014 Share Posted February 8, 2014 The calculation isnt from the ETP, its from the ETOPS Entry Point (or Exit Pt), so earliest arrival is from the ETOPS Entry Point back to the divert field, or the latest arrival is from the exit point, and so on. I had to travel for work this past week, and it has been crazy Wouldn't the latest arrival to ZWWW be from the ETP? Why would the pilot be expected to divert back to ZWWW if he is past the ZWWW/ZLXN? Past the ETP he might very well be past the range for the specified time rule in regards to ZWWW? Link to comment Share on other sites More sharing options...
olmo 5 Posted May 20, 2014 Share Posted May 20, 2014 For US carriers under 121, I no longer need to protect the hour before and hour after, as long as the WX in the window is at/above mins, I'm legal. Before and after the window, it can legally be W0X0F and I am not required to care. Would be nice to have an option to define the "window of suitability", maybe embedded in the fuel policy, since both EU-Ops (AMC20-6 re2, Appendix 5) and Air-OPS (SPA.ETOPS.115) state that:"The operator shall only select [..] an ETOPS en-route alternate aerodrome when the appropriate weather reports or forecasts, [..] indicate that, between the anticipated time of landing until 1 hour after the latest possible time of landing [..]". Other than that there seems to be a small bug related to the ETOPS ALTN Window of Suitability computations since all calculations are referring to STD instead of ETD. Example latest possible landing: OFP AZA610/20 20MAY LIRF/ FCO KJFK/ JFK LIRF 25 / 13 FT X/0/1 EIISE (104.0) 1245/1255 2100/2140 KJFK 22L/ 14 FT [..] E T O P S (180MIN) ENRTE ALTNS (TIME WINDOW OF SUITABILITY -UTC) EINN (1700-2015) CYJT (1859-2015) [..] ONE ENGINE OUT ETP 1 FOR EINN/CYJT N51 19.8 W033 57.4 EET 04:15 1EO84/320 DESC TO FL298 CRUISE AT 1EO320 244 NM BEFORE 5040N PLN FUEL OVER ETP 33170 ETP FUEL REQ 19529 DIV TIME 01:59 [..] ONE ENGINE OUT DECOMP ETP 1 FOR EINN/CYJT N51 17.5 W034 09.6 EET 04:16 EMER DESC TO FL100 CRUISE AT 1EO320 236 NM BEFORE 5040N PLN FUEL OVER ETP 33213 ETP FUEL REQ 23429 DIV TIME 02:35 [..] ALL ENGINE DECOMP ETP 1 FOR EINN/CYJT N51 22.4 W033 43.6 EET 04:14 EMER DESC TO FL100 CRUISE AT LRC 253 NM BEFORE 5040N PLN FUEL OVER ETP 33285 ETP FUEL REQ 21665 DIV TIME 03:17 [..] 20 M270 161 360 482 4860416 *ETP 1 T256 2085 .. -53 339/016 834 33.1 N5117.5 W03409.61711 .... .... A.. .... .... [..] ETP has been correctly based on the worst fuel scenario (ONE ENGINE OUT DECOMP - ETP FUEL REQ 23429) and we expect to be there at 1711. In order to define the suitability window I will take the worst time scenario (ALL ENGINE DECOMP) EET0414 (2'before the critical ETP) = 1711 - 2 = 1709 and add the 0317 diversione time = 2026. We have a 10'gap between our computed latest landing (2026) and the one calculated on the OFP (2015). This error can be easily verified by changing the Taxi Out time. Finally it would be nice to adjust the Window of Suitability when departing from an airport that is also our ETOPS enroute ALTN so that the ETD would be considered as our earliest ETA. Link to comment Share on other sites More sharing options...
olmo 5 Posted June 12, 2014 Share Posted June 12, 2014 Nobody having the issue regarding "Latest Possible Landing"? It can be easily identified by planning two times the same ETOPS flight apart from giving a different STD (try one with STD 0 and the other 1h00m) and you'll see that the time shown on the Window of Suitability won't change. Link to comment Share on other sites More sharing options...
olmo 5 Posted June 13, 2014 Share Posted June 13, 2014 Would be nice to have an option to define the "window of suitability", maybe embedded in the fuel policy, since both EU-Ops (AMC20-6 re2, Appendix 5) and Air-OPS (SPA.ETOPS.115) state that:"The operator shall only select [..] an ETOPS en-route alternate aerodrome when the appropriate weather reports or forecasts, [..] indicate that, between the anticipated time of landing until 1 hour after the latest possible time of landing [..]". Christian has added inside the fuel policy editor two new fields: WOS Before & WOS After (Window of Suitability). Finally it would be nice to adjust the Window of Suitability when departing from an airport that is also our ETOPS enroute ALTN so that the ETD would be considered as our earliest ETA. Christian told that this will be added in the next update. Link to comment Share on other sites More sharing options...
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