Fan of the S-67?

Well put a rotor on my head and a airplane prop on my rear and call me an autogyro... Who knew Sikorsky actually tested a 3.5 ft.-diam. 7-blade fan-in-fin (now copyrighted as "Fenestron" by Eurocopter) on the S-67 "Blackhawk"?

This is the real thing folks, no PS BS here! It was test-flown in 1974 with over 29 flight hours to compare it to the conventional tail rotor. It had a design power of 835 hp and a speed of 3,000 rpm and helped the S-67 gain a speed of 370 km/h (230 mph), thereby beating the original record in which it used the conventional tail. 


In other words it sounds like the test proved very effective, so why did they change it back in August of the same year just before the Farnborough crash in September? O_o
They should have kept it, no doubt. :P