20020810018809A

(.19) On August 10, 2002, about 1350 eastern daylight time, a schempp-hirth standard Cirrus, N47SS, was destroyed when it collided with terrain during takeoff at the Philadelphia Gliderport (0PA0), Hilltown, Pennsylvania. The certificated private pilot was fatally injured. Visual meteorological conditions prevailed for the local flight. No flight plan had been filed for the personal flight that was conducted under 14 CFR part 91. According to a witness, the pilot was in good spirits when he assembled the glider and prepared it for flight. He and the pilot then performed a flight control check. However, the witness only observed the control movements, and not the movement of the cockpit controls. In preparation for takeoff from runway 25, the glider was attached to a 200-foot tow line and positioned behind the tow plane, a Cessna 305. A wing walker reported that he held the wings in a level position as the takeoff was initiated. As the glider gained speed, and he could no longer keep up with it, he turned his back to the takeoff and walked back to the starting point. A third witness reported seeing the glider on the ground after the tow plane had become airborne. A fourth witness reported: "...the glider became airborne and began to rise above the tow-plane. It appeared that after the glider continued to rise, the glider pilot took corrective action to get down to the correct position, but over-shot the mark....the glider appeared to be starting to pio [pilot induced oscillation]...in the 2nd pio the glider did not appear to be excessively high - maybe 5 to 10 feet above the ground. In this second pio the glider did make contact with the ground. The glider then started a 3rd pio - this time it got some what high - maybe 20 to 30 feet. The glider then headed down to the ground at a steeper angle than the previous two pios. Upon impact, I witnessed material parting company with the glider...the wings flexed downward severely, and I thought that at that time a wing might break...the glider bounced up, and then appeared to fly straight with wings level and the fuselage facing directly down the runway, at a slight angle of descent...suddenly the glider appeared to accelerate and pitch up into a steep climb. It looked similar to the beginning of a winch launch. The climb angle continued to increase at a steady rate, and the glider slowed to a stall in a nose high attitude, which appeared to be well above 60 degrees above [the] horizon. The glider then quickly pitched downward and impacted in a nose down attitude." Other witnesses reported similar observations, and that the wing spoilers were extended as the glider was climbing. The tow plane pilot reported that initially, the tow was normal. He then felt his airplane being pulled nose left and low by movement of the glider. The tow rope broke before the tow plane pilot could disconnect the glider. Examination of the turf runway revealed two ground impact marks in line with each other, and separated by about 145 feet, on a heading of 240 degrees magnetic. The first impact mark was 13 feet long, and about 4 inches wide, and the second impact mark was 28 feet long, with a similar width. Another ground scar was found parallel to, and 24 feet, 6 inches, to the right side of the 2nd impact mark. The smaller ground scar was 8 feet 6 inches long, and about 1 1/2 inches wide. At the end of the second impact mark, pieces of curved plexiglass were found. In addition, items that had been located inside the cockpit were also found in this area. A debris trail extended for 110 feet from the start of the second impact mark. The tow rope, which had failed near the tow plane attach point and had separated from the glider, was found within the second ground impact debris field. The glider came to rest at the edge of a mowed area of grass, about 740 feet from the start of the second ground impact mark, on a magnetic heading of 258 degrees. The glider was inverted, and orientated toward a heading of 170 degrees magnetic. Small pieces of grass were found imbedded in the leading edge of the right wing. Both wings had multiple compressive fractures along their length. The wing spoilers were extended on both wings. The fuselage was crushed rearward and the fiberglass shell that retained the cockpit was shattered. The aft fuselage was intact to the vertical stabilizer, where there was a circumferential fracture in the fiberglass. The vertical stabilizer was intact, with the separated rudder laying nearby. The stabilator was mounted on top of the vertical stabilizer. The view window on the top of the stabilator, used to check engagement of the c-hook, was in place and not obscured. The stabilator was jammed in a leading edge up, trailing edge down position. Flight control continuity was verified to the rudder and ailerons. Breaks were found in the elevator control system within the crushed cockpit area. All breaks occurred at other than connections between control rods, and all breaks were bright and granular in appearance. Elevator control through the fuselage pushrods, and into the vertical stabilizer, was verified. The c-hook, which was mounted on the end of the elevator control push rod and was used to engage the roller bearing on the stabilator, was found positioned in front of, and not connected to the roller bearing. The flight control system of another standard Cirrus was examined. Initially, the stabilator was not attached to the vertical stabilizer. To attach it, the stabilator was positioned with the leading edge down about 45 degrees. It was then lowered, positioning the roller bearing in front of the c-hook. The stabilator was then rotated leading-edge-up to the horizontal position, while two alignment pins and a locking pin were engaged. Once the three pins were engaged, the stabilator was locked in place. It was possible to mount and lock the stabilator to the vertical fin with the c-hook in front of, and not engaged with, the roller bearing. When the c-hook was not engaged with the roller bearing, movement of the cockpit control stick still brought about a corresponding movement of the stabilator. However, the movement was outside the range specified by the type certificate sheet for the glider of + 2.65 inches and -1.77 inches. According to records from the federal aviation administration (FAA), the pilot held a private pilot certificate with airplane single and multi-engine land, and instrument airplane ratings. In addition, he held a glider rating. FAA records indicated a total flight experience of about 3,000 hours. The pilot was a member of the Philadelphia glider council, which operated the Philadelphia Gliderport. According to the pilot's glider logbook and glider council records, the pilot's total glider flight experience was about 70 hours, with about 25 hours in the accident glider, and included at least 17 flights. Based upon available records, the accident glider was the first glider that the pilot had assembled. Witnesses reported that the pilot experienced difficulty with the assembly. (-23) horizontal stabilator incorrectly installed on glider by pilot prior to flight, resulting in only nose-down elevator authority. Pilot failed to abort take-off on tow. Glider was towed approximately 100 feet into air, pitched up, broke tow rope, and struck ground in near-vertical attitude. Pilot was killed and glider destroyed.