Answer:
r >= 1799.3 m
or 1799.3 m minimum.
Explanation:
As the pilot cannot pull more than 3 g's, the centripetal acceleration must be less than or equal to three times the force of gravity which is
3×9.8 m/s² =29.4 m/s².
Acceleration (Centripetal acceleration) is the tangential speed squared divided by the radius of the circle or V^2/r. So we have
Centripetal acceleration=V²/r
230²/r=3×9.8
52900/r=29.4
52900=29.4r
52900/29.4=r
Now
1799.3<=r
r >= 1799.3 m
or 1799.3 m minimum.