The most reliable route for this task, is to follow the ridge line along the forestry block to the trig point.  Take care to maintain enough height and forward speed to make it back to the Flight Park. If you don't have enough height to come back from the trig point, it is possible to land at the airstrip near the Arrowtown end of the forestry block.

WK097 Rocky Gully takeoff

WK092 Forest Trig (end of forestry block closest to Arrowtown)

Wk093 Finish at Flight Park