Cessna Stationair/Turbo Stationair 6
Flight Crew Commercial; Flight Crew Instrument; Flight Crew Multiengine
Flight Crew Last 90 Days 50; Flight Crew Total 5600; Flight Crew Type 15
Aircraft Equipment Problem Critical; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway
Flight Crew Overcame Equipment Problem; Flight Crew Regained Aircraft Control; General Maintenance Action
Aircraft
Everything [was] stable and normal in the flight and the approach. Taking a couple of passengers and some equipment to their work site; landing on 100 FT wide; paved runway at operational airport. Loading of aircraft verified within CG range and under maximum gross weight prior to flight. Light wind down the runway at 5 KTS. Touched down on main wheels on centerline and appropriate speed. When nose wheel lowered to the runway; the aircraft violently and immediately veered sharply left. Full right rudder applied and braking in response. Veering did not stop and steering did not respond until aircraft was nearly off the runway at a 45 degree angle; and then just straightened out. This aircraft has a STOL kit and will hop back into the air at 50 MPH if nose is brought back up with any vigor. At that weight; and at the rapid diversion to 45 degrees off runway heading; did not want to risk popping back into the air without the power to pull the beast free of ground effect. Best course of action at that point was to roll through the relatively smooth grass and dirt between runway and parallel taxiway; then steer straight rather than to try and return to the runway or apply power for a go-around. Aircraft rolled straight through the grass - tracks revealed a straight line at approximately 45 degrees to the runway; then taxied normally once on the parallel taxiway. Bumping along the grass set off the ELT; which was subsequently reset. Nothing on the ground came into contact with the aircraft; i.e. signs; lights; etc. [We] dropped passengers and equipment. Called A&P. Inspected aircraft; reset ELT. [We] did taxi tests; steering tests; and high speed taxi test on the runway. All operations checked good. [We] flew to home airport with pilot only on board. Normal landing; no issues; found ASRS reports similar to this event; and spoke to a very experienced C206 pilot who indicates this is not an unusual event in this type. A&P has grounded the aircraft at this time until the nose gear assembly can be inspected; cleaned; and lubricated. Other mechanics and pilots spoken to report the C206 nose wheel steering is problematic with the linkages and disconnects the system utilizes; and the lack of a grease fitting on the upper bearing is a flaw (according to mechanics); especially if not constantly lubricated or if the bearings or other linkage components freeze or fail due to inadequate servicing. No aircraft damage. No injuries.
Cessna 206 departed the runway during a routine landing.