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Guest Bill Yiannakos

Out of trim situations on landing

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From the v1 patch 2 and after, I experience trim problems on landing. The problem is the following:When I'm down the glideslop I decelarate to catch the Vref speed for the landing. Until 20 knots above the Vref, the airplane can be trimmed just fine. But when decelarating further down to Vref, the trim cant compensate the low speed and isn't able to maintain the correct aircraft attitude, because it (the trim) reaches it limit nose-up position.This happens even in hand-flying or in autopilot: from a speed of about 20 knots above Vref and down to Vref, the trim tabs reach their extreme final positions, so the airplane cannot maintain a correct pitch attitude and I am forced to pull the yoke back in order to keep the nose up for the landing..This happens in all gross weights. The trim just reatches its limit nose-up position (when I land and look outside to the horizontal stabilizers, I find them to their fully up position!) and in order to maintain Vref I'm forced to pull the yoke. So, either to Vref is computed wrong by the airspeed indicator, or the trim does not have the right amount of travel......Any ideas about this problem??PS:v1.1 is really impresive :-jumpy -----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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I'd start by taking a critical look at how the jet is loaded...might be that your CG is too far fwd. I haven't seen this myself.CheersBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

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>I'd start by taking a critical look at how the jet is>loaded...might be that your CG is too far fwd.I usually use FSPassengers for my flights, but the problem occurs even when I don't use FSP.... I've checked the CG position, and it is correct...Actually, when flying with FSP, I usually get a little back CG, what -in normal conditions- would lead to a nose-up tedency.... :-roll -----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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What do you mean by "correct" with respect to the CG? What is the C.G, and how did you determine what is is?You can always bump up "elevator_trim_effectiveness" in the airctraft.cfg, but beware, you stand a risk of mking the trim hypersensitive by doing that.RegardsBob ScottATP IMEL GUlfstream II-III-IV-V L-300Santiago de Chile

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>What do you mean by "correct" with respect to the CG? What>is the C.G, and how did you determine what is is?When loading the aircraft within FSPassengers, the dialog box contains a "CG indicator" which shows the actual CG position and informs you when it is within limits.... I use this as reference :-roll >You can always bump up "elevator_trim_effectiveness" in the>airctraft.cfg, but beware, you stand a risk of mking the trim>hypersensitive by doing that.I didn't know that....I'll try to "play" with it, but the fact that no one else has this problems may mean that I'm doing something wrong..... :-roll -----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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Bill; I don't know what FSP considers to be "within limits"...but if it's using the MSFS standard (the same logic that shows the CG in the aircraft fuel/payload dialogue) it's probably going to be nonsense. There's a CG gauge in the TinMouse II...if you click on the invisible clickspot below the VVI a box will open up and display TAT and CG. Please let me know what gross weight, CG (per my gauge) and speeds you're flying when you run out of trim. This should be reproducible.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

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>Please let me know what gross weight, CG>(per my gauge) and speeds you're flying when you run out of>trim. This should be reproducible.It happens regardles of gross weight!!An example: GW 30617 kgs ,Vref (40 deg flaps) 104 kts, CG 24.4%Thanks for the support :-beerchug -----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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Are you using both the b737-200adv.air file (dated 5 Aug 06) and the aircraft.cfg from the V1.1 download? I just flew an approach and trimmed it right down to stall speed with a lot of room still to go before hitting the limit. You can send me your aircraft.cfg and I'll take a look, but I have no no idea why you'd see this.RegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

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>Are you using both the b737-200adv.air file (dated 5 Aug 06)>and the aircraft.cfg from the V1.1 download?I use the FFX model and just unzipped the aircraft.cfg from v1.1 package to its folder (the only modification I did was to enter my textures). I'm attaching my aircraft.cfg to the message....-----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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Bill;OK, now I see what you're doing wrong.In each of your fltsim.x sections you have the linesim=cf732v2004.airSo you are using Charlie Fox's cf732v2004.air file from the original Richard Probst TinMouse panel with the TinMouse II aircraft.cfg file. Bad juju.Change all of those lines to readsim=737-200advRegardsBob ScottATP IMEL Gulfstream II-III-IV-V L-300Santiago de Chile

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>So you are using Charlie Fox's cf732v2004.air file from the>original Richard Probst TinMouse panel with the TinMouse II>aircraft.cfg file. Bad juju.>>Change all of those lines to readI was sure that it had to be a silly mistake from me!! :-shy :-hang Thanks a lot for the support, now it flies like a dream!! :-jumpy :-wave -----------------------Bill Yiannakoswww.yiannakos.netdynamics.gr

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