Pitcairn XO-61
The Pitcairn XO-61 was an American autogyro designed by Pitcairn Aircraft. One of the last autogyros produced, in competition with the Kellett YO-60 and the Sikorsky R-4, it fell victim to cooling problems with its rear-mounted engine and the coming of the helicopter with its ability to hover.
Also known by the company model number PA-44 and the contract designation MX-157, the contract for the XO-61 was taken over by G&A Aircraft upon G&A's acquisition of Pitcairn Aircraft.