Incident Details
During a touch-and-go landing at an unspecified airport, a Cessna T182T veered off the runway and collided with a taxiway sign. The flight instructor (CFI) reported that the first two circuits around the traffic pattern were uneventful, and the student performed satisfactorily. During the third touch-and-go landing, the student indicated that the airplane turned right without application of right rudder pressure. The CFI responded by instructing the student in proper rudder pedal usage.
The flight continued around the traffic pattern. The student then performed a normal power-on approach with 30 degrees of wing flaps extended for another touch-and-go landing. The touchdown was not hard, and no vibrations or unusual noises were noted. As the student increased engine power for takeoff and raised the wing flaps, the airplane again began an uncommanded right turn. The student told the CFI to take control, and the CFI immediately took the controls and applied left rudder to redirect the airplane back onto the runway. However, when the CFI pushed the left pedal, the airplane veered further to the right and collided with a taxiway sign.
Thereafter, the CFI elected to continue the takeoff; full engine power was developed, and the airplane took off. During the climb, both pilots had difficulty maintaining control of the airplane. The CFI made an emergency landing at the airport on runway 30. The touchdown, rollout, and taxi to parking were accomplished by the CFI without difficulty. No unusual sounds, vibrations, or braking problems were noted.
Post-Incident Inspection
All tires remained inflated. An exhaustive examination of the control system, nose wheel steering mechanism, and brakes/tires found no evidence of an anomaly. A series of low- and high-speed taxi tests up to 55 knots were performed with the accident airplane under the supervision of FAA Inspectors, and the airplane operated normally with no difficulty maintaining directional control.
Ground Steering Tests
Cessna Aircraft Company personnel subsequently performed a ground steering test on an exemplar airplane to determine nose gear operating characteristics as the nose tire lifts off the ground. When the nose strut extends to the point where the tire is no longer on the ground, the strut/wheel is designed to center and lock out rudder pedal steering. The test results noted three specific pitch attitudes:
1. With the center of the leading edge of the elevator approximately 34 inches above the ground, the nose wheel was on the ground, and the strut and wheel turned when rudder pedals were operated. 2. When the center of the leading edge of the elevator was 29.5 inches above the ground, the nose tire was just touching the ground, and the nose wheel did not turn with application of rudder pedals. 3. When the center of the leading edge of the elevator was about 16 inches above the ground (with the tailcone tiedown also contacting the ground), the nose wheel was off the ground and would not move using rudder pedals.
The FAA reported that the top of the "J2" sign was about 34 inches above ground level. In a normal three-point resting attitude, the airplane's elevator is about 41 inches above ground level. To contact the top of the taxiway sign, a Cessna T182T needs to pitch upward such that its elevator lowers 7 inches.