9 hours ago9 hr 7 hours ago, JYW said:👍 VNAV aside, did you not climb in FLC/IAS mode? Where the speed could be set higher to prevent an uncomfortable climb rate, but while still providing stall protection?Well, no, because in FLCH mode the AFCS holds climb power and maintains speed by varying the deck angle, producing some noticeable porpoising in certain conditions (e.g. turbulence, wind shifts, transition through thermal boundaries) as the acft chases the speed target with pitch. In V/S mode, the AFCS uses power changes to maintain speed. And once you're at 250 KIAS, a speed target increase is usually not possible until passing 10,000 ft MSL due to regulatory speed limits.It's a phenomenon most likely to present an issue in an acft capable of long international range when flying lightweight, as the high thrust-to-weight ratio makes the normal VNAV climb too aggressive for comfort. In the G-5, we flew a lot of short legs, but the two Rolls Royce-BMW BR710s produce enough thrusties to climb right to FL410 with enough fuel for a 12-hour overwater leg, so we were quite the rocket when light. Just looking at the numbers, a 777 flying a 1-2 hour leg with less than a 30% load (like the aforementioned SCEL-SAEZ leg) would have similar issues. 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
8 hours ago8 hr 46 minutes ago, Bob Scott said:once you're at 250 KIAS, a speed target increase is usually not possible until passing 10,000 ft MSL due to regulatory speed limits.To avoid any misunderstanding, we do exceed 250 below 10K approximately 85% of the time during climb out in this type of equipment. Edited 6 hours ago6 hr by LRBS Missed to mention "during climb out" Freshly retired after 41 unforgettable years on the Boeing 747. The flying days may be behind me, but the memories never will be. Now I have the privilege of sharing those experiences—and continuing to learn alongside the next generation of pilots—in the Level D simulator. Aviation has a way of keeping us all pilots, no matter how many hours we've logged.
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