June 12, 201114 yr Oh ok I see what you are saying. I thought you meant it found itself solely off of DME and didn't have anything else to aid it.Actually most RNAV systems that do DME-based position updates need nothing beyond two DME signals (and the stations' lat/long/altitude) Although at any one instant in time there are two possible solutions for a two-DME intersect, analyzing the trend information as the DME readings change is sufficient absent any other position data to determine which of the two possible loci are the actual aircraft position. Bob Scott | President and CEO, AVSIM Inc ATP Gulfstream II-III-IV-V Sys1 (MSFS20+24/XPlane12+11): AMD 9800X3D, water 2x240mm, MSI MPG X670E Carbon, 64GB GSkill 6000/30, nVidia RTX4090FE Alienware AW3821DW 38" 21:9 GSync, 2x4TB Crucial T705 PCIe5 + 2x2TB Samsung 990 SSD, EVGA 1000P2 PSU, 12.9" iPad Pro Thrustmaster TCA Boeing Yoke, TCA Airbus Sidestick, Twin TCA Airbus Throttle quads, PFC Cirrus Pedals, Coolermaster HAF932 case Sys2 (P3Dv5/v4): i9-13900KS, water 2x360mm, ASUS Z790 Hero, 32GB GSkill 7800MHz CAS36, ASUS RTX4090 Samsung 55" JS8500 4K TV@60Hz, 3x 2TB WD SN850X 1x 4TB Crucial P3 M.2 NVME SSD, EVGA 1600T2 PSU Fiber link to Yamaha RX-V467 Home Theater Receiver, Polk/Klipsch 6" bookshelf speakers, Polk 12" subwoofer, 12.9" iPad Pro PFC yoke/throttle quad/pedals with custom Hall sensor retrofit, Thermaltake View 71 case, Stream Deck XL button box Sys3 (DCS/P3Dv4/ATS/ETS): AMD 7800X3D, MSI MPG X870E Carbon, Noctua NH-D15S, 64GB GSkill 6000/30, EVGA RTX3090 Alienware AW3420DW 34" 21:9 GSync, Corsair HX1000i PSU, 4TB Crucial T705 PCIe5 + 2TB Samsung 970Evo Plus, TM TCA Officer Pack, Saitek combat pedals, TM Warthog, TM RS300 FF wheel/pedals, Coolermaster HAF XB case
June 30, 201114 yr Author That's incorrect. A waypoint has lat and lon coordinates independent of the navigational technique used to reach the waypoint.You may fly to a waypoint's coordinates via GPS, or as used to be the case via Inertial Navigation, LORAN and OMEGA and even VOR/DME or VOR/VOR.Note all waypoints have lat/long coordinates, but some waypoints also have radio beacon bearing and range.Remember FMCs existed for many years before GPS was even invented.Cheers,- jahman.So from what I understand, to fly a waypoint (e.g. DERBB) just flip the nav/gps switch to "gps" and keep nav hold on until you pass the waypoint. Then you switch the nav/gps back to nav, right?
July 1, 201114 yr Interesting topic and one I know very little about so, thinking of earlier times, I'll append my own questions to the previous post...Or dead-reckoning if you are in, for example, a very old plane with no GPS? I'm sure it's physically possible since your flightplan will have a heading, altitude & distance, but would such a thing ever be done in any situation short of some horrible system failure? When were airways introduced and what did pilots do before that?Cheers,D
July 1, 201114 yr When were airways introduced and what did pilots do before that?This old popular site covers it pretty well. http://www.navfltsm.addr.com/index.htm
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