FAIRFIELD, PA, USA
N1154N
Schweizer SGS1-26A
Before takeoff, the pilot installed the wings and tail on the glider. During the takeoff, just after the glider became airborne, it pitched up vertically. After the tow rope was released the nose dropped, and the glider impacted the ground. Examination of the glider revealed that the control cables were rigged in reverse and the elevator control bell-crank located in the aft end of the fuselage was installed inverted from its normal position. About 8 days prior to the accident an airframe and powerplant mechanic with inspector authorization performed an annual inspection which included a statement, 'AC assembled and rigged.' At that time, the complete elevator assembly was not installed. The pilot completed the elevator installation after the annual inspection. Prior to the flight, the pilot was asked by a witness if he had performed a 'positive control check' of the primary flight controls, which the pilot stated 'yes.'
On October 13, 1997, about 1730 eastern daylight time, a Schweizer SGS1-26A, N1154N, a glider, was substantially damaged when it entered an uncontrolled descent after takeoff from the Mid-Atlantic Soaring Center, Fairfield, Pennsylvania. The certificated private pilot received serious injuries. Visual meteorological conditions prevailed for the local flight. No flight plan was filed for the personal flight conducted under 14 CFR Part 91. A witness reported that the glider and towplane departed runway 15, an asphalt runway, on its first flight after maintenance. The glider became airborne after a 20 to 25 foot takeoff roll and began to climb at a high pitch attitude. The tow line was then released, and the glider's pitch attitude increased to about a 75 to 80 degree angle. The nose of the glider then dropped and impacted the ground. The witness stated that just prior to the flight, the wings and tail section of the glider were assembled. The witness had asked the accident pilot if he performed a "positive control check" on the primary flight controls, to which the pilot responded "yes." Another witness stated he observed the glider takeoff and pitch vertically straight up, then after the tow rope was released, the glider's nose pitched down and impacted the ground. The witness also stated that the pilot had been working on the glider for most of the summer, and recently replaced the flight control cables for the elevator. Examination of the wreckage by a Federal Aviation Administration Inspector revealed that the elevator controls were rigged backwards, with the right hand elevator cable going through the top fairlead, and the left hand elevator cable going through the bottom fairlead. According to Schweizer Control Surface Installation Chart, Form I-4073, the left hand elevator cable should have been routed through the top fairlead located in the aft fuselage. Further inspection revealed that the elevator bell-crank located in the aft end of the fuselage was installed inverted from its normal position. The elevator control, located in the cockpit, operated in reverse of normal control operation. Forward movement of the control moved the elevator surface in an upward direction. An airframe and powerplant mechanic with inspector authorization had performed an annual inspection and a flight control check about 8 days prior to accident. The annual write-up included, "AC assembled and rigged." At that time, the complete elevator assembly was not installed. The pilot completed the elevator installation after the annual inspection. No other evidence of pre-impact malfunctions were found with the glider during the examination.
The improper installation of the elevator cables and elevator control bell-crank by the pilot, and an inadequate annual inspection by the mechanic. Also causal was the pilot's inadequate preflight of the flight controls prior to takeoff.
Source: NTSB Aviation Accident Database
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