September 2, 201114 yr Starting to work with the finer points of the NGX. The FMC computed a cruise speed of 0.80M, a tad too high for comfort, red bricks on the speed tape during both climb and cruise, etc. I reduced the speed through the MCP and then entered 0.78M through the CDU/CRZ for the longer-term cruise speed. Can anyone tell me on which performance parameters I should concentrate for correcting the problem ? Any other direction ? With the 400X, I never had to address this type of an issue so I am a bit puzzled. Thanks,Zach zachlog
September 2, 201114 yr The FMC shouldn't be calculating a speed that's overspeeding the AC. Is the Init page data entered correctly? Di Agron Dell XPS 15 L502X | Intel i5-2540m @ 2.60GHz | 4GB DDR3 1333MHz (2x2GB) | nVidia GT525M | Seagate 500GB 7200RPM | 15" 1366x768 | 23" LG 1360x768 | Got a hardware question? Ask: HERE (Mobo's, Ram, CPU's, custom builds, general hardware etc) HERE (Graphics cards, monitors, drivers etc) HERE (Peripherals/Hardware and related drivers) HERE (Internet/Networking) PMDG FMC NavData out of date message fix HERE
September 2, 201114 yr Author The FMC shouldn't be calculating a speed that's overspeeding the AC. Is the Init page data entered correctly? I don't know, is it ? That's one of my questions. See attachment. Zach zachlog
September 2, 201114 yr I don't know, is it ? That's one of my questions. See attachment. ZachThat's a very high Cost Index !! 20-40 is good for the NGX. Frederic Steiner.
September 2, 201114 yr Try using a lower cost index, between 8 and 30 is very common for many airlines. i7-13700KF, 32gb DDR4 3200, RTX 4080, Win 11, MSFS 2024
September 2, 201114 yr Yep! The cost index is too high. I had the same issue the day before yesterday. I wanted to do a quick flight and knowing that the cost index managed the speed I set it at 80 and what do you know?? It went into overspeed, I use 20 as a cost index and the problem dissapeared. I guess there is no "safety" system to prevent the overspeed in the plane. I'm also guessing that the RW version also has this issue. Chris Verner Home cockpit builder ...well trying anyway
September 2, 201114 yr Commercial Member CI is not a linear thing... valid range is 0-500 and most airlines never get above 100 on the NG. Ryan MaziarzFor fastest support, please submit a ticket at http://support.precisionmanuals.com
September 2, 201114 yr Thanks for the answer Ryan, but now I'm curious. I wonder what happens in the real bird if the crew enters a CI of say, 200. I very much doubt that there is no protection against overspeed simply because the FMC is telling the acftto fly faster. But if you of all people tell me that's how it happens in real life, I'll buy it. See that's the problem with the NGX. Éven those who think they know the acft all to well never know whether they've come across a bug or a rw hiccup! I do remember however, once when riding the jumpseat on a 777 that the airline's cost index was 180 and the capt decided to change it to 500 somewhere half along the way because we were lagging behind due to unforecast strong headwinds. Went from M0.84 to M0.86, no overspeed. I know it's different acft but still... Cheers,Victor M. Lima
September 2, 201114 yr Author That's a very high Cost Index !! 20-40 is good for the NGX.Unbelievable, I missed it ! I meant to enter a CI of 30 but I am still getting used to CDU data entry with my keyboard (love it !) and an extra "1" slipped in Thank you and the rest of the people responding ! Zach zachlog
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