20010411006489A

(-23) Pilot experienced severe engine vibration during take-off climb. Pilot reduced power in an attempt to lessen the vibration and attempted an emergency return to the runway. A/c touched-down approx. 100 feet short of the departure runway resulting in substantial damage to the a/c. the left main gear collapsed in the soft gravel runway over-run causing the a/c to ground loop. Damage to the right and left main gear, propellers, flight control cables, and tailboom occurred. The pilot and passenger were not injured. Subsequent investigation revealed that a stainless steel dental pick that the owner was using for minor maintenance had not been accounted for during the tool inventory. The dental pick is presumed to have been left on top of the engine where it became dislodged during the takeoff climb. The dental pick was found in the tailboom during post accident investigation and appears to have struck and fractured the tip of a propeller causing the severe vibration. The propeller slung the dental pick into the tail boom penetrating and causing a deep slice in the tail boom. (.19) on April 11, 2001 at approx. 0930 MDT, a young kolb mark iii, N1225Y , was substantially damaged during a forced landing at Brigham City, Utah. The private pilot received minor injuries and his passengers. (.4) on April 11, 2001, at approximately 0930 mountain daylight time, a young kolb mark iii, an experimental homebuilt, N1225Y, was substantially damaged during a hard landing at Brigham City Airport, Brigham City, Utah. The private pilot received minor injuries and his passenger was not injured. The airplane was being operated by the pilot under title 14 CFR part 91. Visual meteorological conditions prevailed for the local personal flight which was originating at the time of the accident. The pilot had not filed a flight plan. According to the pilot's accident report, he performed a thorough pre-flight examination of the aircraft and departed on runway 34. Upon reaching the pattern altitude of 5,000 feet MSL, the airplane began to "shake violently," like a "prop tip separation." The pilot then reduced power and the shaking minimized. He increased power again and the shaking returned, so he again reduced power. He then initiated a 180 degree turn to return to runway 16, and configured the airplane for best glide angle speed. The pilot realized that he was not going to reach the end of the runway, but he could reach the gravel run out area. The pilot said he was "happy with that spot" and told his passenger that they were going to make an off runway landing. He said he maintained 55 mph until the beginning of the flare. He felt he did not have enough control authority to slow the vertical descent as the airplane "bleeds off energy very fast; the flair [flare] was done at the last moment and we had hit the ground before I could add power." The left main landing gear collapsed, and subsequently the fuselage impacted the ground and skidded for 35 to 50 yards. The bent fuselage rotated and came to rest 180 degrees from the runway heading. The pilot stated "that a FOD (dental pick) used in maintenance two days earlier and not found in two to three times going over the engine and one preflight, had dislodged from [a] hiding place and hit the prop. There is about a 2 x 2 inch section of prop tip missing."