From a bird's eye view, the plane will be flying northeast. The velocity in the direction of flight will be slightly more than 52m/s; it will be the length of the hypotenuse of the right triangle formed by it's east and north velocities.
Its east velocity is 52m/s and its north velocity is 12m/s so its velocity from a bird's eye view is (by the Pythagorean theorem)[tex]\sqrt{52^2+12^2}=\sqrt{2848}=4\sqrt{178}\approx 53.366\text{ m/s}[/tex]