Robin400,
In this case, I don't think that FLARM would have helped you. As ShyTorque has already pointed out, CAA certification issues essentially preclude the installation of FLARM in G reg PT helicopters. So, even if
you had FLARM, you wouldn't have recieved any traffic warning (seeing as FLARM boxes can only talk to other FLARM boxes.)
However, the helicopter would definetely have had a transponder installed (which, hopefully, was transmitting Mode C.) Condsidering that you were in a powered aircraft (I'm guessing some sort of Robin
), then a TAS or TCAS system would've given you a traffic warning.