Sikorsky S-61 modified for S-66 test

[archipeppe]

Lurking on the net, I've found such interesting (and at least for me) previously unseen image of an Sikorsky S-61 Sea King with tail section heavily modified to serve as testbed forerunner of the S-66 AAFS (source https://www.sikorskyarchives.com/S-66 AAFSS.php):