On June 28, 1996, about 1150 eastern daylight time, a Cessna 172N, N4776E, was substantially damaged when it overran the runway during the landing at the Blue Knob Valley Airport, Newry, Pennsylvania. The private pilot and passenger were not injured. Visual meteorological conditions prevailed for the local flight. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. The pilot stated, in the NTSB form 6120.1/2: "My son and I arrived at the airport and I preflighted the airplane. We taxied to the run-up area for runway 29. I "ran-up" the engine, checked the gauges and set the flight instruments and radio. We cleared for take off and during the take-off roll, I noticed the airspeed was not working properly. It bounced a few times and then quit. By this time I was too far down the runway to abort the takeoff. I took off and we flew locally for 1.2 hours. We flew back to the airport to land. I was concerned about coming in too slow and stalling out. I use 10 [degrees] flaps for a final but was too high and fast to touch down. I made a go around and used 20 [degrees] flaps for final. I touched down about 1/3 to 1/2 down the runway, applied full brakes but was still going too fast and ran off the end of the runway." Examination of the wreckage by a Federal Aviation Administration Inspector revealed sediment clogged the pitot tube. According to the Airport Facility Directory, runway 29 was a 3,415 foot long, 92 foot wide, dirt runway with no obstructions. The weather at a nearby airport was reported as ceiling 3,500 broken; visibility 12 miles; temperature 80 degrees F; dewpoint 60 degrees F; altimeter 30.20" Hg; wind from 330 degrees at 7 knots. According to the Cessna 172 Pilot Operating Handbook, for the above conditions, the takeoff and landing distances were approximately 1,300 and 900 feet respectively.