What? I don't see any ramjets on that thing. And your comment about them not being used on manned rotorcraft because they were unsafe is not true at all. Many countries experimented with ramjets only to find that they weren't as efficient as other existing layouts, and that's why no one uses them on production aircraft. Tinsley's Firecopter may not have existed then but we have had rescue helicopters like that for years.
We have here the latest in primitive technology.
Internet + Opinions = OMG we are SCREWED!
This other picture shows it better. This was drawn in 1953. At this time some believed that ramjets in the tips of the rotors would give helicopters of the near future and enourmous amount of extra power. Such a helicopter could fly over the gridlocked streets of Manhatten and get there quicker. Then it would hover over a fire hydrant and lower the hose, which would be connected to the hydrant the powerful helicopter's motor would turn a pump that would suck the water up to the firecopter and pump it through the nozzle that was aimed at the burning building. The high pressure this pump added would send a stream of water through a window. Perhaps Mr. Tinsley had read that the ramjets in blade tips would be some thing efficient after a few years of research and development.
Several ram jet helicopters were built in production, English American and European - jet fuel and natural gas they we're too costly due to fuel burn, as for fire fighting Ericson Air Crane has a nozzle pump assembly for high rise fire fighting.
Heavy Lift tried put Ericson put a stop to it as they patented the concept.