An SA227 Captain reported landing in a freezing drizzle; with braking action reported as fair; to find braking action. Maximum reverse and braking was not sufficient to prevent the aircraft from going off the end of the runway at a very slow speed. No damage reported.

Narrative

Virtually the entire State [was] experiencing freezing drizzle/freezing rain. Weather reported as 1 SM; OVC 200; winds 200/6; temperature -3/dewpoint -4. Center advised braking action 'fair.' Flew ILS and broke out at decision altitude. [I] landed on the 1;000 FT bars at Vref. [I] slowed aircraft with prop reverse through 40 KTS. Relaxed prop reverse and started applying brakes to slow to taxi speed. At this point; I had 2;000 FT to 3;000 FT of runway remaining. Got on the brakes; and quickly realized that I had zero braking action. Given a speed of 30 KTS and 2;000 FT remaining; aborting the landing was not an option. I went to full reverse on the props again and tried to add whatever deceleration that I could with the brakes. As the end got closer I realized that I was either going to barely stop on the runway or that I would overrun. To minimize damage to the aircraft and airport equipment if I did overrun; I did not even try to make the turn off at the end; but allowed the aircraft to slide straight into the grass. [I was] literally at a walking speed and missing taxi lights; localizer antenna; etc. Aircraft came to a stop with the mains approximately five feet off the end of the runway. [I] did not hit a taxi light; antenna; no prop strike. Only visible damage was to main tires; where it appeared that as the aircraft hit the dirt/grass; chunks of tread were ripped from them. Airport Manager came out to meet me at the runway end. As he got out of his truck he almost fell; as we were both standing on a sheet of ice. He stated he was just about to drive the runway again after I landed; but that he was closing the airport immediately; given the then-current conditions. He mentioned that he drove the runway forty minutes prior; and reported the braking action as 'fair;' and that the conditions that I landed in had rapidly worsened since his last report.