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Guest jlwoodward

LANDING GEAR DRAG

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hellohow does one increase only the landing gear drag using fsedit in fs2k2,thnxkunal

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If you use FSEdit, it adds sections (1539-1547) to the *.air file. Section 1540 is the drag section and one of the inputs is gear drag.However, none of the default fs2002 aircraft have these sections, only ones edited with FSEdit. As a matter of fact, deleting these sections seems to make the aircraft fly better using older sections of the *.air file. Section 1011 has gear drag coefficients also, but whether they work in fs2002 is a guess on my part.Download AirEd152 - http://members.dsl-only.net/~eagle/ and the attached aired.ini file below. Rename it aired.ini.You might benefit from a long and detailed discussion on this forum by Ron Freimuth and also by visiting http://www.avhistory.com/ message boards.

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>hello >>how does one increase only the landing gear drag using >fsedit in fs2k2, >kunal Sieffert's reply explains this. Even IF FSEdit managed to generate reasonable, new records in the AIR file it sets LG drag to 0.00. Recent versions of Aired.ini identify the new parameters (concisely). It would be one of the Drag records: "Cdg". I've set it to 0.010 to get a reasonable LG drag in AIR files that I also fixed many other of the new records. That would be '20' in the legacy REC 1101.Ron

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hello Sieffert & Ronthnx for the helpin my version of AirEd( AirEd Copyright

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Yes, I would download the latest AirEd 152 and make sure you also download the latest aired.ini I attached to my first post. This file is kept up-to-date by Ron Freimuth.And as far as "and by the way do u gentlemen know something about fatal exception errors??!!", stay away from them they can be dangerous to your computers health!!!:-lolMy knowledge on those would depend on the error listed. I usually search the Microsoft database when they occur.

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Look for section 1101 Primary Aerodynamics (Not 1011). Click on the "+" to open that section up. Then, scroll down till you see "*Cdg Drag Coefficient - Landing Gear".Just as wsieffert, I have deleted sections 1539-1547. When I have done this, the landing gear drag begins to work.Before you start changing numbers, back your airfile up! Joehttp://myweb.cableone.net/joesumralliii/Reindeer.gif

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>Look for section 1101 Primary Aerodynamics (Not 1011). >Click on the "+" to open that section up. Then, scroll down >till you see "*Cdg Drag Coefficient - Landing Gear". >>Just as wsieffert, I have deleted sections 1539-1547. When >I have done this, the landing gear drag begins to work. >>Before you start changing numbers, back your airfile up! How precisely does one go about deleting the sections 1539-1547. My Socata TB20GT .air file has those sections in it, and now I know why gear drag isn't being simulated! :(I've looked through AirEd and don't see an obvious way of deleting those *)#*& records! :)

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>Bill, what I do is right-click on the offending record and >choose "Remove Record". Thanks! That worked a treat. Now, I gotta go see if I have 'gear drag' now... :)

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>Bill, report back on how the flight test went. I love >success stories! As with everything else in the arcane and archaic 'art' of the .air file, changing one thing usually has unpredictable results...So now, although I do have LOTS of gear drag (I've toned it down now), the entire a/c will now merrily cruise along at 186 kts using MAP 11", RPM 2000... :(Understand that 'normal' cruise performance at 8,000' is 163 kts, 20" MAP, 2000 RPM.Full throttle, max RPM will generate a 'cruise speed' of 232 kts! Who the heck strapped a booster rocket to the Socata TB20GT? :)

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Well, it's already gotten out of my league. Maybe someone will jump in here and shed some light on the excess speed you have.You've got a "project airfile" to work with now.I tell ya, having some drag when I drop the gear to help me get down to a speed where I can lower the approach flaps, is where it's at for me and complex aircraft.If you don't have that drag, those slick airplanes just keep on sailing.I've got a suggestion...if you have a plane that's similar in performance and power and kind of acts like it's supposed to, open it's airfile side by side with the Scocata's. Maybe there is drastically different about the Scocat's airfile that will jump out at you.Good luck with it and remember...we're having fun!Joe http://myweb.cableone.net/joesumralliii/Reindeer.gif

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Hi Bill,>As with everything else in the arcane and archaic 'art' of >the .air file, changing one thing usually has unpredictable >results... >>So now, although I do have LOTS of gear drag (I've toned it >down now), the entire a/c will now merrily cruise along at >186 kts using MAP 11", RPM 2000... :( >>Understand that 'normal' cruise performance at 8,000' is 163 >kts, 20" MAP, 2000 RPM. Here are some realistic values for drags. I adjust them a bit in the final tweaks to get appropriate performance. Real and scaled by 2048 for REC 1101. Cdo Drag - Zero Lift: SEL: 0.028 '56'; Jet: 0.018 '36' Cdg Drag - Landing Gear: 0.01 - 0.02 '20' to '40' Add Cdg for Fixed Gear AC to get total 'Cdo' Cd_f Drag - Flaps: 0.075 to 0.110 '150' to '220' Cd_s Drag - Spoiler: 0.015 '30' Induced Drag is set from Wing data in aircraft.cfg. I suggest my previous comments on setting the Wing in aircraft.cfg be used. However, the Oswald_Efficiency in aircraft.cfg increases that drag. 0.70 is appropriate for a low wing AC, 0.80 for a high wing AC. In faster AC, 'Mach Drag' becomes significant above Mach 0.80. This is set in TBL 430 and is also scaled by 2048. However, that table is almost always set too high. Better to set no more than '5' at Mach 0.8 (you have to count 0.2 Mach per x) and about '50' at Mach 1.0. One can adjust Cdo with the 'parasite_drag_scalar' in aircraft.cfg. However, many drags can't be set in that file; better to have it appropriate in the AIR file. Small adjustments might be more convenient in aircraft.cfg. AFSD displays these drags in real units. Also, the sum, CD. ----------------------- Assuming thrust/power is appropriate, these drags should give reasonable speeds. In fact, I adjust Cdo to tweek the top speed for SEL's. AFSD displays HP, thrust, etc. One should be sure a reciprocating engine developes rated HP at SL. I'll comment on the lines in aircraft.cfg that set this some other time. However, HP is proportional to number of cylinders and displacment per cylinder. The 'HP setting' in aircraft.cfg does not change HP! With appropriate drags, a SEL should use the appropriate fuel with 'fuel_flow_scalar=1.00'. However, the default fuel consumption for jets SFC is too low (0.50). More approriate values range from 0.57 to 0.88. So, set 'fuel_flow_scalar' to 1.12 to 1.89. Higher for older technology turbines (JT8). Turboprop AC may require some adjustment to 'fuel_flow_scalar', but 1.0 is roughly correct. Change it to adjust fuel flow once the SHP and speeds are appropriate.Ron

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> Hi Bill, > AFSD displays these drags in real units. Also, the sum, >CD. Thanks, Ron...Hey, should I be concerned that AFSD won't display any data for the Socata TB20GT? :)AFSD simply attempts to load the data, then recycles...Other a/c display just fine!

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>Thanks, Ron... >>Hey, should I be concerned that AFSD won't display >any data for the Socata TB20GT? :) >>AFSD simply attempts to load the data, then recycles... >Other a/c display just fine! Ah. AFSD doesn't yet account for parasite_drag_scalar, etc when they are not equal to 1.00. However, the 'stability' and some other scalars can be set to something other than 1.000. Also, AFSD doesn't handle the new records in an AIR file when FSEbar'ed. I know how to handle them, they will be added in the future. Also, AFSD may not read aircraft.cfg correctly. Herve' fixed one problem I found, but I see it doesn't like station loads that are not sequencial in number. Even though FS2K uses them OK. All that did is show some of the payload as 'ice weight'. Which is reported in his last version (probably not generally released). Ron

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