AIR AMBULANCE JET ENCOUNTERS MOUNTAIN WAVE DOWNDRAFT AT FL430. HAS ENG FLAMEOUT AS TRYING TO ADJUST PWR TO MAINTAIN ALT. DSNDS; RESTART.

Narrative

THE EVENT OCCURRED AT FL430 IN A SMT ON AN AIR AMBULANCE TRANSPORT. THE FLT WAS NORMAL UNTIL A MOUNTAIN WAVE OVER THE TETONS WAS ENCOUNTERED. AIRSPD STARTED SLOWING UNTIL AT .72 THE PLT INCREASED THE PWR SLIGHTLY TO STOP THE AIRSPD FROM SLOWING ANY FURTHER. AT .69-.70 THE PLT BROUGHT A LARGE PWR CHANGE (FROM 92-96%) TO INCREASE AIRSPD. THE R ENG FLAMED OUT. ATC WAS INFORMED AND A DSCNT CLRNC WAS OBTAINED TO FL250. THE ENG SHUTDOWN CHK WAS ACCOMPLISHED AND AT FL250 THE ENG WAS RE-STARTED. THE ACFT CLBED BACK TO FL410 AND FINISHED THE FLT WITHOUT FURTHER INCIDENT. UNDER FILING A RPT (FAR 135.415 (6) I STATED THAT PLT TECHNIQUE WAS A CAUSE TO THE FLAMEOUT. IT WAS DETERMINED THAT THE ENG DID NOT HAVE ANY PROBLEMS. AFTER TALKING WITH THE OWNER OF THE ACFT; IT WAS DISCOVERED THAT THIS AIRPLANE IS CERTIFIED ONLY TO FL410. THIS AIRPLANE HAS HAD MANY MODIFICATIONS INCLUDING BEING CERTIFIED TO FL450 UNDER A RESTR CATEGORY. IT IS VERY CONFUSING WHILE READING THE LOGS TO DETERMINE IF IT IS CERTIFIED TO FL450. A CALL TO MANUFACTURER WAS MADE TO GET THE FINAL FLT LEVEL CERTIFICATION. I DO NOT BELIEVE THAT CRUISING AT FL430 LED TO THE CAUSE OF THE FLAMEOUT.