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Found 2 results

  1. First of all, Thanks the great effort FeelThere put in to the SP1 aerodynamic tweak, the over all aerodynamic performence turn from V2 and non-sp1's totall mess into something I think only need some final adjustment. Here is 2 small thing I noticed: 1.FMS's LRC is about 0.01~0.02 Mach slower on E190, and about 0.01 faster on E170 compare to the Manual I have, not huge difference, but somewhat noticeable. 2. I see the Fuel flow for climb and cruise is about 1.1 times higher than the chart, then I look into the Aircraft.cfg, fond there are fuel_flow_scalar=1.12 and =1.1 on E170 and E190's data, once I reset them to 1.0, the crz FF and trip fuel use is dead accurate to the realworld data, is it just some typo or last minute change forgot? Hope it get fixed.
  2. I made some tweaks for feelthere E-jets E190 mainly in aircraft.cfg and emb190.air to get better aerodynamic performence math to the realword data. These tweak I originally mad for FS9 version, but after I move to P3dv4 just last year, I found it's still needed and works. The realword data source is E190 Airplane Opreation Manual I found online, you may try to search it, but I won't provide. AOM is for opreational and NOT for aerodynamic or performance engineering, just keep that in mind. Rather than simply put were you need to modify, I'd rather share some backgorund information, so any other people intersted in, or hopefully devs working on new 64bit version, could get something useful. And if you try to implant my tweaks, just remember back up your files! So first time I got the AOM, I immediately try it's Simplified flight planning charts to make fuel and time cauculation for my sim flight, it turns out the fuel used is way off the caculation, that starts my journey for aero editing, to get the perrformence I needed. The goal is: a reasonable fuel predection, so a nice match in cruise is 1st priority, then the Climb and Decent better to math tables too, for the take-off and landing part, I just wanna make sure with proper Vspeed, the aircraft could climb with single engine if needed, and not ruin it when things changed with cruise preformence., and for cruise under FL250 which i typically won't do, and Hold at low level and any other flight phase inside or outside the envelope, I simply didn't try to work on it. First thing I noticed is, the curise performence is way off the ALL ENGINES OPERATING CRUISE TABLE in AOM, so I just set the weight, the FL, use AP/AT to see,the behaivor, and adjust the cruise_lift_scalar and engine thrust curves to match the N1 needed to keep level flight at given speed The only part I touched with emb190.air is the 1506 table, Thrust vs N1 and Mach No, I can'y copy it into text, so here is the table: M, 0, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105 0.0, 0.00, 0.11, 0.15, 0.18, 0.20, 0.24, 0.28, 0.30, 0.39, 0.46, 0.54, 0.59, 0.64, 0.72, 0.89, 1.00, 1.11, 1.15, 1.17 0.2, 0.00, 0.05, 0.07, 0.10, 0.14, 0.17, 0.23, 0.30, 0.39, 0.46, 0.54, 0.59, 0.64, 0.73, 0.89, 1.00, 1.11, 1.15, 1.17 0.4, 0.00, 0.07, 0.10, 0.14, 0.18, 0.21, 0.26, 0.30, 0.39, 0.46, 0.54, 0.59, 0.64, 0.73, 0.89, 1.00, 1.11, 1.15, 1.17 0.6, 0.00, 0.11, 0.16, 0.20, 0.25, 0.30, 0.35, 0.39, 0.45, 0.51, 0.58, 0.61, 0.65, 0.68, 0.92, 1.08, 1.23, 1.23, 1.25 0.7 ,0.00, 0.20, 0.23, 0.27, 0.32, 0.36, 0.41, 0.44, 0.51, 0.59, 0.65, 0.71, 0.75, 0.79, 0.97, 1.18, 1.35, 1.36, 1.38 0.9 ,0.00, 0.23, 0.27, 0.31, 0.36, 0.40, 0.46, 0.50, 0.59, 0.68, 0.75, 0.83, 0.90, 0.94, 1.10, 1.29, 1.37, 1.40, 1.45 Ah, I just can't keep it in line... go figure... I edit it with AirEd, you can find it free online, and there are other tools. for Aircraft.cfg: [flight_tuning] cruise_lift_scalar=1.260 [jet_engine] thrust_scalar=0.83 Now, that makes N1 match within 7~10% at a normal cruise, I'm ok with this. But the goal is fuel flow, after more test flight, I get this. [GeneralEngineData] fuel_flow_scalar=1.35 [TurbineEngineData] fuel_flow_gain=0.0012 Now the fuel flow for most cruising condition is in 5% error, i feel good with that. Notice, these are final results I got, so you can just use it, But I also did flight test with Takeoff Landing, and climb/des and do more tweaks to make sure it doesn't ruin these condtion. the low mach region in 1506 table is manily for that. The climb and decend data I just try to match the time show on AOM table, since speed is keeped by AP/AT and thus distance, The error now is less than 2 minutes from sea level all the way up to FL350, But it nolonger match the FMC VNAV prediction in feelthere. Another problem I had is the Trim goes wild when apparoching, so I get some tweak here too, to make it more reasonable, Now the trim for approach is like 4~5 unit.: [flight_tuning] elevator_trim_effectiveness=3.500 [airplane_geometry] htail_incidence=-18 side effect is, The AOA are rather low at high speed decent, while OK when cruising. Also, according to AOM, the take off trim should be near 1 for a 25% CG, but in feelthere avionics the green band is near 3, so the trim for this tweak is still somewhere near 3, for not to set off the alarm, the AOM table not works here. To fix the approach performence, I needed to add some lift for flaps: [flaps.0] lift_scalar=1.20 The "green dot" on speed tape just not work well, The flaps manuver speed in AOM shows: UP 210 1 180 2 160 3 150 4 140 5 140 6 130 For take off with Flaps 2, you retract to 1 above retcation alt, and speed above 160, then after speed hit 180, retract up. the green dot just way too high For approach, Flaps1 when 210, slow to 180, Flaps2 when hit 180 and slow to 160... you get the idea.... That's all modifcation I made is only for E190, I've tried to fit it in E170 as it is, but it doen't work, I had the E170 AOM in imperial units, I had a check but just to see it doen't match well, and don't want spend more time on it. E175 and 195, I don't even have the data. FOR E170: 1506 table same as E190 [jet_engine] thrust_scalar=0.780 [GeneralEngineData] fuel_flow_scalar=1.18000 [TurbineEngineData] fuel_flow_gain=0.0012 [flight_tuning] cruise_lift_scalar=1.26 elevator_trim_effectiveness=2.000 don't change others E170 is better on trim and LRC by FMC Know issue that I can't change. Hopefully get corrected with New 64bit version: TO trim not match AOM, but works great by just set it in 3~4 units.(it works great on 170) After take off, don't follow FD for climb, just pitch up to get speed V2+10~20 will be fine. Greendot on speed tape for flaps not match, I just use the AOM data and it better fit the performence, even without these editing. For P3Dv4 version, CLB2 is neede, somehow the N1 I get is higher than what AT set, and with CLB1, it could corss N1 redline, however not seen in FS9 version (It's OK for 170) FMC VNAV climb just not fit. FMC LRC speed way too slow, if you calculate fuel with LRC chart, manully adjust the mach number to where LRC table shows, around 0.72~0.78ish according to weight and Flight Level. rather than 0.65ish in feelthere FMC. or simply go M0.78 cruise. (LRC works great on E170) Surprisingly, FMC fuel predection is OK. VNAV decent could be use, with Enging not idel but 40+ N1. VNAV won't handle At or Above type of ALT restriction, it only goes "At" it could trigger way too earlier TOD in some STARs. When descending, AOA looks very low or even minus. Autopilot not follow glide slope very well, manual fly it will be OK. Hope you enjoy these tweaks. At least for me, the E190 is now flyable for some nice route at day light, Thanks feelthere to provde a decent avionics and normal system opreation to start with. The new V3 170.190 is also off figure by now, but hope Feelthere will get it better!
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