Piasecki helicopter is looking to demonstrat higher speeds in its vectored-thrust ducted propeller (VTDP) X-49 Speedhawk demonstrator. (paid subscription required)

They are currently installing a 3rd engine to power the propulsor, and expand the envelope to 193 kts (223 mph).

In the meantime, Sikorsky is looking toward taking its X-2 advancing blade helicopter to about 250 kts (288 mph). It’s already powered up the propulsor on the ground, and they look to open the envelope slowly, as this is a privately funded project.

Interestingly enough, it appears that they may exceed 250 kts in test at some point, as the manager of advanced programs notes, “We are comfortable getting to a 250-kt. cruise. The dash speed will be higher.”

I can see one or both of these technologies as a replacement for the A-10, which is a fine aircraft, but the US Air Force has wanted it dead for 30 years, and they only grudgingly address the close air support needs of ground troops.