Michael J. as per real world procedures, a value of 0 would program the jet to clb, des and crz at mach .780 aprox...Choosing LRC AND 0 ON THE GROUND BEFORE ENGINE START! Will result in a flight analasys of the flight and process a suitable cruising speed for best range and economy...That is the only way I can fly in head wind from VHHH to Europe...ALSO CI of 0 and LRC is the only combination I have found to be working for head wind flying. For tail/cross wind ops a higher crz number is the best choice as choosing .830 instead of .850 would actually cost you more fuel because of prolonged crz time in total...Above I am referring to real world BA 744 flightplanning routes I have gotten my hands on :-)But please either CI of 0 and LRC in head wind and a higher CI or higher Mach crz speed, not LRC and a CI of 90 in tail wind conditions, test it out, I have no problems flying long distances... BUT ZFW should not be 230+kgs or so.Oh and http://flightaware.com/ is awesome but only gives accurate information on flight originating from the US.Boaz...

BTW...Michael thanks for the link to the website, that's a very nice site.

>The definition of LRC is Long Range Cruise, and according to>the manual can be selected where you sacrifice speed in order>to maintain fuel efficiency. How does this compare to your>statement?Long Range Cruise is NOT best range cruise or what Boeing rather calls Maximum Range Cruise (MRC). People often take term Long Range Cruise intuitively not knowing this is a very precise thing.Boeing defines LRC as flying with speed that consumes 1% more fuel per trip than flying MRC (CI = 0). LRC speed is usually 10 to 20 kts faster than MRC speed. Of course all these speeds are weight dependent. The higher the weight the faster they are.I don't think you can have it clearer than this.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

>So why does it say>in the PMDG manual that flying at .86 and at FL350 should>yield a TAS/IAS of 476/276 ???Bug in the manual?Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

I'm a novice and not sure I follow all the ins and outs of LRC but just last night I set up to fly from LA to Sydney. The FMC indicated I'd have 18.0 fuel left on arrival but we ran out of fuel when I had just passed HAWAII! That's getting less than half the distance I think we should have seen. The head wind was about 300 relative and at 30kts for most of the flight. I read your suggestions on lowering ZFW but isn't that cheating realism just a bit? So, what did I do wrong?

>2. LRC AT CI 40 is very close to LRC at CI 0. There is only one LRC per definition (read my post below). There is no such thing as LRC at CI 40 and LRC at CI 0.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

As to the wind factor - it is entirely possible that the fully functioning FMC takes winds under consideration when doing its cost analysis. If this is the case then Maximum Range Cruise is obtained by using CI = 0 with or without wind. I could not locate anything in the official Honeywell/Boeing manuals about whether winds are factored in the trip cost analysis.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

If Boeing says so then I guess you are right.BA how ever fly with the specs I gave earlier when flying west bound in head wind conditions and then fly at CI 90 the other way...I have found out that the only way I could stay with in my calculated fuel reserve with out even touching the speed enroute, was to fly using BAs configuration, so that is what I can recommend you try.Boaz...

>If Boeing says so then I guess you are right.Boaz,I have access to Boeing's developed Computer Based Training (CBT) that defines all these terms. Thanks for other info.Michael J.http://www.precisionmanuals.com/images/forum/pmdg_744F.jpghttp://www.hifisim.com/images/asv_beta_member.jpg

Hi Mikkel,I used to make 2-3 roundtrips on this flight every year. No, this flight - UA895 KORD-VHHH - is normally a non-stop flight. It is quite rare (maybe 2-3 times a year) that it makes a fuel stop and usually, it'll stop in PANC, ZBAA or RKSI.You can't fly this route using the route found by http://rfinder.asalink.net/free/ planner because it doesn't give you a polar route, which is what the flight does in real life. (I saw a bunch of real-world flight plans in this thread that would be a true representation of what the flight does.) By polar route, I mean the flight actually flies north from KORD, goes over the North Pole and then comes back down South through Russia and China (hence the fuel stop in ZBAA when needed). It's only when the polar radiation is too high that the flight will fly the traditional trans-Pacific route and that's when a stop in PANC would be needed.FWIW, it used to be that UA would fly trans-Pacific on the Eastbound UA896 VHHH-KORD and only polar on the Westbound UA895 KORD-VHHH. I think it was because Russia only opened its airspace for a limited number of flights each year and the fees were quite high. I don't know about what UA does now.Hope this helps.Edwin