The first YUH-61 was rolled out of the Boeing Vertol factory in Ridley Park, just west of PHL, on 9 September 1974 and the caption from Veriflite suggests the photo was taken there. The first flight was made from the Grumman factory airfield at Calverton, NY. The UH-61 lost the UTTAS (Utility Tactical Transport Aircraft System) competition to the Sikorsky UH-60. Photo from: Vertical Flight Society

The UH-60 and the AH-64 won, the UH-61 and the AH-63 lost and it seems their manufacturers like to forget about these loser designs. One prototype of a civilian variant of the H-61 was built. It reportedly first flew on 5 August 1975, but was already on display at the Paris Air Show in June. Petroleum Helicopters took options on 28 aircraft, but Boeing cancelled the type after it failed to win military orders. A naval variant, the Model 237, lost out to the SH-61 and was never built. It looks like the photo was taken at the factory in Ridley Park, with the Delaware River in the background, but this is unconfirmed. Photo from: Vertical Flight Society