On August 18, 2018, about 1000 Alaska daylight time, a Cessna U206F airplane, N441GR, sustained substantial damage while landing at a remote unimproved tidal beach about 36 miles east of Pedro Bay, Alaska. The airplane was registered to AK Air Leasing, LLC and operated by K Bay Air, LLC as a visual flight rules (VFR) on-demand commercial flight under the provisions of 14 Code of Federal Regulations Part 135 when the accident occurred. The commercial pilot and five passengers were not injured. Visual meteorological conditions prevailed, and company flight following procedures were in effect. The flight departed Homer, Alaska, about 0900. According to the pilot, before landing on the tidal beach, he conducted two passes over the landing area to check for debris and determine wind direction. After a stable approach, the left main and uphill tire touched down first followed by the right main tire. The pilot stated that after touchdown, it "felt like" the airplane had a flat tire and it subsequently veered to the right and came to rest in a left wing low attitude on a tidal mudflat. The airplane sustained substantial damage to the left wing, left horizontal stabilizer and left elevator. An initial examination of the airplane, by the pilot, revealed that both main landing gear legs separated just above the main axle attach point. An examination by the National Transportation Safety Board (NTSB) Materials Laboratory revealed that both main landing gear legs exhibited chevron marks leading to a thumbnail region consistent with fatigue cracking. The NTSB Materials Laboratory examination report is in the public docket for this accident.