Uniform circular motion - plane in a circular arc

[Sean1218]

Homework Statement

As a pilot comes out of a dive in a circular arc she experiences an upward acceleration of 9.0 gs (i.e. 9 x 9.8).

a) Mentions that the Pilot's mass is 60 kg, already solved this

b) If the speed of the plane is 330 km/h, what is the radius of the plane's arc?

Homework Equations

a_c = v²/r
F_net = $$\Sigma$$F

The Attempt at a Solution

No idea what to do because I can't figure out what is causing the centripetal acceleration.

mv²/r = - mg

I don't know the mass of the plane, and if I add another force which I assume would cause the centripetal acceleration then I have no way of calculating that either.

 

[rock.freak667]

The upward acceleration the pilot experiences is directed towards the center of rotation, so you are given the centripetal acceleration.