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Stabalising aircraft on take-off and landing

PostPosted: Sun Sep 11, 2005 4:50 am
by Wingo
OK, i've got a small AG-14 that i got from a PC Pilot CD. ON take off and landing, when ever the airspeed rises above around 20 KIAS it starts jumping around like a kangaroo on steroids, and makes the tasks very interesting to perform. Is there any way i can increase the stabability of this craft??

Re: Stabalising aircraft on take-off and landing

PostPosted: Sun Sep 11, 2005 5:42 am
by Ecko
I have the same problem, and I haven't found a solution yet.

I tried changing the air file, but that didnt do it. It must be something in the config file.

Re: Stabalising aircraft on take-off and landing

PostPosted: Sun Sep 11, 2005 7:25 am
by dave3cu
If you can give a download file name/location we could check it out.......otherwise:

Have a look in the aircraft.cfg file, [Contact Points] section.

First check out the 'strut' parameters, items 8,9, and 10 for 'wheel' class'. Too 'loose' or 'tight' can cause your problem. See how they compare to a similar aircraft.

(from the C172)
       //0  Class (1=wheels, 2=scrape.......)
       //1  Longitudinal Position        (feet)
       //2  Lateral Position             (feet)
       //3  Vertical Position            (feet)
       //4  Impact Damage Threshold      (Feet Per Minute)
       //5  Brake Map                   (0=None, 1=Left, 2=Right)
       //6  Wheel Radius                (feet)
       //7  Steer Angle                         (degrees)
       //8  Static Compression           (feet)  (0 if rigid)
       //9  Max/Static Compression Ratio
       //10 Damping Ratio               (0=Undamped, 1=Critically Damped)
       //11 Extension Time              (seconds)
       //12 Retraction Time             (seconds)
       //13 Sound Type
[contact_points]
point.0 = 1,  0.90,  0.00, -4.09, 1500, 0, 0.5, 22.0, 0.25,2.5, 0.7, 0.0, 0.0, 0
point.1 = 1, -4.70, -4.50, -4.01, 3500, 1, 0.5,  0.0, 0.3, 2.5, 0.7, 0.0, 0.0, 2
point.2 = 1, -4.70,  4.50, -4.01, 3500, 2, 0.5,  0.0, 0.3, 2.5, 0.7, 0.0, 0.0, 3
point.3 = 2, -3.90, -18.0,  3.00, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 5
point.4 = 2, -3.90   18.0,  3.00, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 6
point.5=  2,-20.23,   0.0,  0.30, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 9
point.6=  2,  1.48,   0.0, -2.17, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 4
point.7=  2,-22.80,   0.0,  5.83, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 7
point.8=  2, -4.90,   0.0, -2.00, 1800, 0, 0.0,  0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 8

Another possibility is errant 'Scrape' points, Class=2.

Taxi off the runway, grass or dirt, and look for dirt flying up from points it shouldnt be. Adjust the location as necessary, items 1,2, and 3.

As always make sure you have a backup file before editing.

Dave

Re: Stabalising aircraft on take-off and landing

PostPosted: Sun Sep 11, 2005 8:19 am
by Ecko
It's the one at the top of the page!

http://www.simviation.com/fs2004props65.htm

Re: Stabalising aircraft on take-off and landing

PostPosted: Sun Sep 11, 2005 11:38 pm
by Wingo
Ok, yes there was a bad scrap point... there was a blank one at the refrun point. I deleted it. I also increasd the empty pitch MOI which has stabled it. I think i need to increas the roll MOI as it rolls back and forth a bit now (it went unnoticed with the massive pitching on take off)