HI, I live in Juneau, Alaska and frequently drive up a 3 mile icy road to the ski area. I have Blizzak radials in excellent condition on my LS, not-G80 rear diff. In pure ice conditions I always use 4-high. I have many decades of experience driving in mountain areas on ice and know how it feels to to loose traction in the front and rear and and how to mitigate it. I've driven many hundreds of times up this steep icy road many times with all types of front wheel, rear wheel, AWD, and 4WD vehicles and never experienced what happened to my LS yesterday. Though I have previously momentarily lost traction for a fraction of a second in the steep and icy upward 10% slope section of this ski area road in my LS, it was easy to recover traction by instantly reducing my foot from the gas pedal. Yesterday at 30mph and in 4-high,in this icy upward sloped section of road, the LS lurched left and fishtailed 8 ft into the oncoming traffic lane. I immediately removed accelerator pressure within a fraction of a second of feeling the loss of traction and steered out of the skid, regaining enough traction to steer back into the right lane where it fishtailed slightly in the other direction before regaining traction, all without touching the accelerator. Somehow I missed the 10' snow berms on both sides and no cars crested the hill top 100' in front of me when this dance was happening. Obviously, I never touched the brake during this sequence. It felt like both left front and left rear tires simultaneously lost traction while the right front and rear were still under power, yet with my foot off the accelerator the moment I detected a loss of traction. i have no error lights on the transfer case switch or anywhere else. I've searched the archives for answers. Can someone explain how the drivetrain could cause this to happen? Is there some drivetrain testing or something else I should ask the dealership to check, or should I just give up on my LS and always drive my subaru to go up that road in icy conditions?