Gulfstream IV / G350 / G450
Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 30; Flight Crew Total 4000; Flight Crew Type 100
Aircraft Equipment Problem Less Severe; Ground Event / Encounter Loss Of Aircraft Control; Ground Excursion Runway
General None Reported / Taken
Aircraft
Approach was briefed for an ILS. VFR conditions with skies clear and 10 miles visibility and winds calm. Aircraft touched down on first third of runway well within touch down zone. The main gear touched down then I placed the nose gear on the runway. Aircraft started veering right of center line. We tried to correct but the aircraft deviated off and to the right side of runway at about the 2;500 FT mark down the runway's right side. Aircraft came to a stop 30 feet off side of runway on the grass area.
The reporter stated that subsequent to the incident he was told the nose wheel steering computer failed and commanded a 20 degree right input which caused the crew to veer off the runway. This nose wheel steering computer is a third generation box; which has had moisture issues in the past. No damage to aircraft.
[Report narrative contained no additional information.]
G-IV flight crew lowered the nose wheel on landing and the aircraft veered to the right off the runway due to a malfunction of the nose wheel steering system.