On January 15, 2001, at 0730 hours Pacific standard time, a Cessna T210L, N2508S, and a Cessna 310, N890GR, collided on the ground in the run-up area for runway 29 at San Luis Obispo Airport, San Luis Obispo, California. Both airplanes sustained substantial damage. The Cessna T210L was operated by the private pilot/owner, who was not injured, as a business flight under the provisions of 14 CFR Part 91. The Cessna 310 was rented by a commercial pilot for a business flight under 14 CFR Part 91, and neither he nor his passenger were injured. Visual meteorological conditions prevailed, and both airplanes were preparing to depart. The Cessna T210L pilot had filed an IFR flight plan to Palomar, California, and intended to receive his clearance airborne. The Cessna 310 pilot intended to fly VFR to Santa Monica, California, and no flight plan was filed. Both pilots were interviewed by Safety Board investigators. The pilot of the taxing Cessna T210L stated that the morning sun restricted his vision to the point that he did not see the Cessna 310 in the run-up area. The pilot of the Cessna 310 stated his airplane was stationary and he was looking inside performing prop governor checks and at the last second saw a "white flash" in the corner of his eye. The right wing of the Cessna T210L was severed approximately 6 feet inboard of the wingtip when it contacted the right propeller of the Cessna 310. The Cessna 310 suffered damage to the right propeller, engine, right wing fuel tank, and sudden engine stoppage.