Wheels vs Skids
Just two observations from early Blackhawk/S-70 days:
1. The Army had done considerable study work prior to letting the UTTAS Request for Proposal out, and had concluded that for a helicopter of that size, wheels were the better solution. A Col Bud Patnode was in charge of this work, and he relayed that the discussions often became heated with the " if its on the Huey, its perfect" community.
2. Qualification testing of that aircraft recognized that if one has tires and struts maintained by humans, they will inevitably become improperly serviced at some point. Therefore, mechanical stability ( ground resonance ) testing was done at various CG's and Weights with a matrix of mis-serviced tires and struts. My recollection was that there was no tendency to self induce ground resonance except at full aft CG somewhere about 50% airborne, and with the cyclic almost full aft, just producing light droop stop contact ( brakes had to be on, and all in all, this is a pretty unusual state to be in ) . One had to wait a half minute or so before the ship would start off at 2/3P. ( this was on level concrete, a condition considered more conducive to ground resonance than softer ground ).
Thanks,
John Dixson