It’s probable that a bent-down microphone jack receptacle–a non-OEM installation–found near the base of the copilot’s control column prevented aft movement of the yoke, causing a Challenger 600 to overrun the runway during takeoff from Tupelo Regional Airport, Miss., on March 9, according to a Bombardier Advisory Wire sent to operators of 600-series Challengers. “An inspection of the copilot control column revealed that the handheld microphone jack receptacle mounted on the lower aft side of each control column approximately one-inch from the bottom of the column was bent downwards,” the March 13 advisory said. “With the receptacle in this position, when the control column was pulled aft, the receptacle contacted the control column cover and prevented further aft movement of the column.” Bombardier said the origin of the installation is not known at this time.