contour chasing

Verb

contour chase (third-person singular simple present contour chases, present participle contour chasing, simple past and past participle contour chased)

1. To fly an aircraft at low altitude, following the shape of the ground below.
   • Latterly the visibility, due to the dense haze, had been poor indeed—they had to practically contour chase portions of the way in order to keep the "road" in sight. All hands, however, were glad to be on the job after the long flight from Melbourne […]1937, Michael Terry, Sand and Sun