problem with tail wheel

[gosd]

In some aircrafts when I start the plane moving on take off the tail wheel bouces and digs in the ground leaving a groove behind.
How can I correct this using the .cfg file, is it the tail wheel position or static_pitch or the static_height?

 

[hairyspin]

Forget about static pitch or height, they just place the model when it's first loaded in the sim.

In the contact points section of aircraft.cfg, you're looking for the tailwheel line. This is the stock P-51D:-

[contact_points]
//0 Class
//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
//14 Airspeed limit for retraction (KIAS)
//15 Airspeed that gear gets damage at (KIAS)
point.0=1.000000,-23.600000,0.000000,-3.3000,2165.354000,0.000000,0.549000,180.0,0.253000,2.500000,0.498000,1.000000,1.000000,0.000000,150.000000,160.000000
point.1=1.000000,-7.900000,-5.917000,-7.200000,2165.354000,1.000000,0.549000,0.000000,0.633000,2.500000,0.800000,13.500000,13.500000,2.000000,150.000000,160.000000
point.2=1.000000,-7.900000,5.917000,-7.200000,2165.354000,2.000000,0.549000,0.000000,0.633000,2.500000,0.800000,13.000000,13.000000,3.000000,150.000000,160.000000

The lines beginning // are comments: the lines of numbers after these are what we want. In this case, the tailwheel is point.0

First, the contact point Class (first number in line) is 1 so it's a wheel.
The lateral position (third in line of numbers) is zero so it's on the aircraft centreline and is therefore a tail or nose wheel.
The Impact Damage Threshold in feet per minute (fifth number) is the value to increase to make the tailwheel sturdier.

Hope this helps.