was on a VFR flight to South Indian Lake with two crew and a nurse on board. After the a/c landed on Runway 36, the pilot attempted to brake the a/c, but found that the right brake pedal was "flat" and he attempted to pump the brake to get it to engage. The a/c pulled to the left where it caught the windrow and it subsequently left the runway surface. The a/c broke off one runway light, one threshold light and sheared off the a/c's landing gear. The pilot also reported some icy patches on the gravel surface of the runway. There were no reported injuries. More details will follow. UPDATE The medevac flight received an airport advisory that the winds at South Indian Lake were 300 degrees at 15 mph and that the runway was 80% bare and dry. The crew touched down about 1/3 of the way down the 2600 foot runway and when they applied the brakes, the right one was "soft". The a/c drifted left, struck a windrow of snow and came to rest 20 feet off the runway near the runway end marker lights. No injuries were reported but the a/c sustained substantial damage to the landing gear, propellers and fuselage. The crew later reported that a substantial portion of the runway was covered with snow and ice and that the winds were 270 degrees at 15 knots.