On January 25, 1997, at 1400 eastern standard time, a Cessna 402C, N121PB, registered to Hyannis Air Service Inc., of Hyannis, Massachusetts, doing business as Cape Air 1088, sustained minor damage when it overran the runway during landing at the Provincetown Airport, Provincetown, Massachusetts. Instrument meteorological conditions prevailed, and an IFR flight plan had been filed. The certificated airline transport pilot and four passengers were not injured. The scheduled commuter flight was conducted under 14 CFR Part 135, and originated in Boston, Massachusetts, at 1330. The pilot reported that he checked the destination weather twice, once before departure, and the second prior to commencing the ILS 7 approach. He executed the approach, and made a normal touchdown. During the rollout, he experienced a strong, sudden, quartering tailwind, with wind gusts of approximately 20 knots. He said: "...The gust of wind carried the airplane down the runway instantaneously precluded a go-around and rendered braking ineffective. I employed maximum braking technique to bring the aircraft to a stop... ." The airplane then exited the runway onto the soft overrun area, and the right main gear collapsed. One of the passengers said, "...[when] the airplane touched down it seemed to veer a bit from side to side. It didn't slow down, and suddenly we were out of runway... ." The witness said it was very foggy. The pilot said he acquired the runway at approximately 250 feet AGL. He said the runway was wet, and there was patchy standing water. The weather briefing the pilot received prior to commencing the approach stated the winds were from 220 degrees at 12 knots. He said he was within the aircraft limitations, and the Automated Weather Observing System (AWOS) reports showed the winds began to gust after his normal approach and touchdown. The pilot stated there was no mechanical malfunction with the airplane. A Federal Aviation Administration Inspector reported that the airplane had touched down about 700 feet down the 3,498 foot long runway. The decision height for the ILS was 208 feet AGL. The Provincetown 1355 AWOS, reported winds from 220 degrees at 15 knots; visibility, 1/2 mile in fog; ceiling, 100 feet; temperature,43 degrees Fahrenheit (F); dewpoint, 43 F; and altimeter, 29.67 Hg. Five days after the accident, the airline issued parameters for arrivals and departures from the airport, which included landing with a maximum tailwind of 10 knots.