Originally Posted by Dave Jackson
The link in post #1 says that the Hybrid Tandem Rotor could achieve a forward speed of 225 kts, but the video appears to show turbo-jets.
I look at that video and see nacelles containing gearbox, coolers and turbo shaft engine aligned in-line. Although it would be possible to take a turbo-jet, modify it M88-style to produce both thrust and shaft power, that would easily increased the max speed without complicating the overall design. The problem is - those kind of modifications are not really successful (TP400-D1 was canceled, and TP400-D6 have problems).
Originally Posted by riff raff
Even though it would have a lower forward speed, apparently Bell thinks it is a better compromise overall?
Both have its pros and cons. The X2 have small footprint but at this stage no backup plan for the worst case scenario - gearbox catastrophic failure, that HTR would provide just having those wings, plus HTR would require a lot less power at cruise speed.
I love to see those design concepts, especially the LHX program was a golden age of weird drawings. The problem here I see also is with promoting the design to military first. I'm not sure this is a good idea, there is a rare opportunity today, with recent crashes - to promote development of a design that could bring people down safely in case of catastrophic gearbox failure in offshore environment. HTR can have this potential, and not exploiting this opportunity seems weird
