In the installation folder, under Official/OneStore, you will find each aircraft has it's own folder. With the Cessna 152, for example, in the asobo-aircraft-c152/simobjects/Airplanes/Asobo_C152 folder, you find the cameras.cfg file (each aircraft has its own cameras.cfg file). In this file there is a list of camera definitions. Camera definition 18 is the external view I'm talking about (unfortunately it's not the same for each aircraft). Under [CAMERADEFINITION.18] you will find InitialXyz and InitialPbh.
InitialXyz is the position of the camera, and InitialPbh is the angle of the camera. If you set InitialXyz to 0,0,-10, the camera will be 10 units behind the plane, if you set InitialPbh to 0,0,0 it should be looking straight ahead at the aircraft (the update replaced my editing with the default values, but I'm pretty sure that's what it was).