Primary finding
Probable cause
The flight instructor’s failure to ensure clearance from an electrical junction box during takeoff, which resulted in a collision.
Investigator assessment
Analysis narrative
The flight instructor of the glider reported that the takeoff for the instruction flight was along a grass area adjacent to a paved runway. The takeoff began with the right wing down to practice a standard unassisted takeoff. As the takeoff roll began, the right wing rose, and the glider entered ground effect. Several seconds later, the flight instructor heard a “boom” as the glider bounced up. He then released the tow rope and landed straight down the grass runway uneventfully. The flight instructor exited the glider and noted damage to the right wing as a result of a collision with an electrical junction box for the runway’s precision approach path indicator. He added that there were no preimpact mechanical malfunctions with the glider. Postaccident examination of the glider by a Federal Aviation Administration inspector confirmed substantial damage to the glider’s right aileron.