Originally Posted by SansAnhedral
Well for JHL, the program office actually had settled on a (quad) tiltrotor solution only
Not quite true. Prior to the JHL effort being folded into the JFTL AoA (which included various fixed-wing STOL and V/STOL designs) in late 2010, the concept definition work had been narrowed down to three candidate configurations:
- Bell's QTR (with 55 ft diameter rotors)
- A conventional tiltrotor (CTR) that Bell had additionally been funded to study in parallel with QTR (with 80 ft diameter rotors)
- Karem's OSTR (specifically the TR75, with 75 ft diameter rotors). As you may recall, the Army's "representative" JHL configuration used for wargaming purposes from 2007 on – the High Efficiency Tilt Rotor (HETR) – was very reminiscent of the OSTR.
The three concepts from the original JHL CDA that had already been dropped by this time were the Boeing Advanced Tandem Rotor Helicopter (ATRH), the Sikorsky X2 Technology Crane (X2C) and the X2 Technology High Speed Lifter (X2HSL).
I/C