Gulfstream IV / G350 / G450
Flight Crew Air Transport Pilot (ATP)
Aircraft Equipment Problem Critical
Flight Crew Diverted; General Declared Emergency
Aircraft
While en route at FL400 we received a red CAS message 'Engine Exceedance' and observed the left engine TGT spiking two or three times between 910-990 degrees (left throttle was retarded during that period); which is beyond engine limitations. We consulted the aircrafts QRH and AFM manuals for 'Engine Exceedance.' Per checklist procedure we retarded the throttle to idle and the engine TGT returned to normal operating limits. We were unable to maintain FL400 with the left engine at idle. An emergency was declared and a descent was initiated. We requested and were given divert to the nearest suitable airport. Brief holding was required to achieve landing weight and the eventual landing was uneventful.
A Gulfstream IV with spiking TGT in the left engine diverted to a nearby airport with the engine at idle.