Helicopter/FJ interaction. Two Wessex, and a Hunter trying to catch them out. Wessex decide to hide behind a hedge. This worked well, until a Pawnee crop-sprayer decided to take a look at us. Pawnee coming up on the starboard side, the opposite side of the hedge. Hunter approaching from three o'clock. No common frequency. I had visions of the Hunter hitting the Pawnee, and the wreckage falling on two rotors-running Wessex. Luckily the Hunter pilot saw the Pawnee at the last moment, and avoided him. We met a very white-faced Hunter pilot in the crewroom later.