This is actually the easiest contract, IF, you plan ahead.
You MUST have a helo for this contract. Ideally, the DPRK MD-500 or Mafia MD-530 are what you want.
Fly directly over Taechon and the reactor area. When you clear the ridgeline to the north, drop down to wave top level and fly north while skirting the red zone. When you see a cliff, climb slowly and blow your horn, then move in low and slow to land. When you land, blow the horn for the agent to climb in. When he does, climb high and move south as quickly as possible to avoid the Type-95 AAMs. Head for the yellow circle, land and done.
Yes, this works. Works every time I try it.