So I already got the answer for the first part:

Question

An airplane is flying in a horizontal circle at a speed of 102 m/s. The 80.0 kg pilot does not want the centripetal acceleration to exceed 6.18 times free-fall acceleration.
Find the minimum radius of the plane's path. The acceleration due to gravity is 9.81 m/s2.

The answer is 171.79

The second part is what I need help with:
At this radius, what is the magnitude of the net force that maintains circular motion exerted on the pilot by the seat belts, the friction against the seat, and so fourth. Answer in units of N.

Please explain how you got your answer. Thanks so much!