Plane and sphere intersection

I have 3 points that forms a plane and a sphere with radius 6378.137 that is earth. I want the intersection of plane and sphere.

below is my code , it is not showing sphere and plane intersection

clc;

clear all;

pos1 = [1721.983459 6743.093409 -99.586968 ];

pos2 = [1631.384326 6813.006958 37.698529];

pos3 = [1776.584150 6686.909340 60.228160];

normal = cross(pos1-pos2, pos1-pos3)

syms x y z

p = [x y z];

planefun = dot(normal,p-pos1);

zplane = solve(planefun,z)

figure

ezmesh(zplane)

hold on

[x, y, z] = sphere;

r = 6378.137;

x = x*r;

y = y*r;

z = z*r;

surf(x,y,z)

Answer 1

[Sulaymon Eshkabilov]

A couple of points require some changes, e.g.:

...
figure
fmesh(zplane)   
hold on
[x, y, z] = sphere(50);  % A bit more meshing
r = 6378.137*1000;       % Scaling problem
x = x*r;
y = y*r;
z = z*r;
surf(x,y,z)

[kalpana bandi]

I am using 2015a version, I am getting error for fmesh