Some months ago I looked at Bell's V-280 Valor entry into the US Army's Future Vertical Lift competition. I noted:
When you consider safe separation distances in a landing zone, combined with the probability of having to perform insertions and extractions in confined terrain (natural or man-made - i.e. urban), I'm not at all sure how well the V-280 design will perform, simply because it's so big. It may be forced to land and take off in more open spaces, further away from the action. That will force troops to march further to where they're needed, or fight their way back to their helicopters for extraction. That'll add time and, probably, casualties to the operation - and that can't be a good thing.
. . .
Sikorsky-Boeing's SB-1 Defiant proposal for the FVL program, on the other hand, has a similar footprint to conventional helicopters, despite being much faster. It's not flying yet, but here's a promotional video from Sikorsky-Boeing, showing what it will look like. Note that they're showing it operating in a confined urban environment - perhaps deliberately, to emphasize that it'll be compact enough to be able to work there.
There's more at the link, including videos and other images.
I was reminded of that earlier article when I came across this video clip at The Aviationist. It shows helicopters from the 160th Special Operations Aviation Regiment, exercising in the streets of Los Angeles. Note the very tight landing zones used by the helicopters. Even the small MH-6 Little Bird helicopters must require very careful handling to get in and out of such spaces, much less the larger Blackhawks (both types are shown in the video).
The video drives home my earlier concerns. Landing on streets like that, with wires, tree branches, etc. obstructing access, is difficult enough even in a small helicopter. The SB-1 Defiant, with its coaxial main rotor system, should be able to get into far more compact landing zones than the V-280 Valor (as described in the earlier article). From my own experience with helicopters as a passenger "up the sharp end", I'd say that's a supremely important consideration; yet the tilt-rotor V-280 is considered a viable contender in the competition.
What say my military and veteran readers? Am I putting too much emphasis on this tactical consideration, rather than other elements of the competition? Are there other factors that make the size and accessibility of the landing zone a less important requirement?