Defiant X article.
https://verticalmag.com/news/defiant...ce-black-hawk/
From the article:
Defiant has logged 1,500 hours in Sikorsky’s systems integration laboratory (SIL), and 135 hours on the ground-based propulsion systems test bed (PSTB). After a rocky start, Defiant
roared through a series of test milestones in 2020.
In the two years since its first flight, the demonstration aircraft has performed 31 test flights, accumulating 26 total flight hours, according to the Defiant team.With two-thirds prop torque and engine power, Defiant has achieved 211 knots in straight-and-level flight and
232 knots during a descent.
While this may just be the article's author cherry picking past articles it confirms that SB has not released any updated information since June 2020. This seems to confirm no progress or flights (?) in six months. So what is wrong. If it was just drag keeping the top speed low they could have flown it to expand the GW/CG and ALT/TEMP envelopes which would gather meaningful data for any proposal and padded the flight hours to look less than the pathetically low 26 hours. I believe the demo was suppose to be at least 100 flight hours with the 280 demo ship good for at least a 200 flight hour campaign.. Giving up in doing anything since June when they needed to make substantial progress to even be a dark horse alternative to the 280 if Bell stumbled (which the Bell team didn't) points to a flight safety issue (or issues) that could not be overcome. Many have speculated high vibration, but in my experience pilot bonus money overcomes that issue. So we are looking at loads so high that catastrophic failure within a limited number of flights could occur or a danger the rotors could collide like what was already demonstrated on the S-97. It will be interesting to find out what metaphorically killed the SB-1 prototype.