Strange that the charities can afford to upgrade from Bo105 to EC135 and the like but not go the extra mile for TCAS. Since the argument for upgrade was no doubt increased safety and reduced operating costs it is false economy to scrimp on TCAS if you really believe there is a real threat of losing an aircraft.
I had 2 different FJ fly close to me today both coming from behind (one during a PFL and the other positioning for ILS) but they both saw me and manoeuvred away - maybe it was the white strobes, maybe it was the hover floods, maybe it was just the aircraft they saw but they saw me and that was in reducing vis due to light snow showers.
In the South West we get a lot of low level FJ traffic because there is little regulated airspace and few built up areas to avoid but we manage without TCAS.
Maybe you should look at how many jobs you get launched to that aren't really essential but keep your callout stats high to please the charity and the NHS and then consider your exposure time to the 'FJ threat' during non-urgent lifesaving flights.
I am sure I seem hard nosed and unreasonable about this but everyone loves to slag off the military because we are an easy target.
If you want FJ pilot reaction and comments then post on the Military Aircrew thread but don't be surprised at the response.
No FJ crew goes out to frighten helicopter pilots and they don't launch without proper briefing and planning (including CANPs). Neither do they deliberately overfly AA or police HLS and since they don't know which field you will be in on a job they can hardly be expected to avoid you there.