[Freeport]

Correct, but the arrangement shown, above & behind the fuselage, like other aircraft that make use of this arrangement, does reduce / eliminate the noise problem in the aircraft.

But I wouldn’t want to live on the runway approaches!

[Yo-Yo]

That arrangement is due to practicality. You simply cannot mount an UDF engine on a wing. The blades will strike the ground.

Green sky thinking - carbon credits and the propfan comeback?

Part of the reason is the configuration changes that are required to support open rotors sized for the 25,000lb-thrust (110kN) class. Compared to the GE90-115B, currently the biggest engine in the world with a fan diameter of 3.3m (128in), the LEAP56 open rotor is provisionally outlined with a 4.3m-diameter set of blades.

"So the other piece of technology is how do you install it, and how do you certify something like that?" asks Clapper.

[Yo-Yo]

It's the airport noise that counts. The passengers can just turn up their headsets!

;^)