Incident Overview
The captain supervised fueling and weight and balance computations, while the first officer completed the takeoff and landing distance (TOLD) card. A center of gravity (CG) location was not computed. The first officer entered a takeoff gross weight of 45,400 pounds on the TOLD card, with corresponding V-speeds of V1 116 knots and Vr 129 knots. Post-accident calculations revealed that the actual gross takeoff weight was 46,481 pounds and the CG was 15.73% of mean aerodynamic chord (MAC). These values were within the maximum gross takeoff weight and CG limits of 46,500 pounds and 14 to 31% MAC, respectively. The correct V-speeds for the actual weight were V1 118 knots and Vr 131 knots.
Stabilizer Trim Setting
The crew set the stabilizer trim at -5.5 degrees, which is within the takeoff range of -4.5 degrees (labeled "AFT") to -7.5 degrees (labeled "FWD"). For the airplane's calculated CG of 15.73% MAC, the appropriate stabilizer trim setting should have been between -7 and -7.5 degrees.
Takeoff and Abort
The captain reported that everything was normal during the takeoff roll. The first officer called V1, followed by Vr. At Vr, the first officer pulled back on the yoke but observed no response. When the speed reached the upper 130-knot range, he relaxed the yoke and then pulled aft again, again with no response from the airplane. The captain then aborted the takeoff. The airplane came to rest 580 feet beyond the departure end of the runway after impacting a berm.
Post-Accident Findings
A post-accident inspection of the airplane revealed that all systems were operating within allowable tolerances. Simulator testing configured for the accident conditions (stabilizer trim at -5.5 degrees and V-speeds for 45,400 pounds) showed a delay of 2 to 4 seconds between an up elevator input and the airplane's pitch response. When the simulator was configured with the stabilizer trim at -7.0 degrees and V-speeds for 46,480 pounds, no delay was observed.