Gulfstream IV / G350 / G450
Flight Crew Flight Engineer; Flight Crew Multiengine; Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 40; Flight Crew Total 5600; Flight Crew Type 850
Situational Awareness; Troubleshooting; Workload; Time Pressure
Aircraft Equipment Problem Critical; Deviation - Altitude Overshoot
Flight Crew FLC Overrode Automation; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Took Evasive Action; Flight Crew Regained Aircraft Control
Environment - Non Weather Related; Aircraft
During climb with the autopilot engaged; the aircraft attempted to level off at assigned altitude of FL280. The aircraft began to porpoise and the electric pitch trim failed. The autopilot disconnected and the aircraft climbed to 28;300 FT. Evasive action was immediately taken to correct the altitude deviation by hand flying the aircraft. The electric pitch trim was reset and autopilot was re-engaged. We were then given a higher altitude assigned and began to climb to it when the electric trim failed again and the autopilot disconnected. We informed ATC that we were no longer RVSM equipped due to equipment failure. We requested descent to FL280 to leave RVSM airspace and continued the flight at that altitude until descent.
A G-IV electric pitch trim failed while climbing into RVSM airspace which caused an altitude overshoot at FL283 so RVSM was canceled and the flight continued at FL280.