What engine would you then say the AF plane above ( in service until late 70s at least) has ,JT4A?
I pressume all -3C engines were the first to be replaced by fans due to the pollution ...
I would love to hear again and compare the sound of -3C, -4A, -3D fitted planes on take off. I do remember the early 707 engines producing a penetrating high pitch whine even in idle something late engines did not have.
RR Darts such as on the Viscount & Andover were never quietened still have that loud whine.