Helicopter pilot reported multiple engine flame outs occurred due to a detached fuel nozzle.

Narrative

SAFETY REPORT - FLAMEOUT and FUEL NOZZLE FAILUREAircraft Type: MD Helicopters MD600N. Engine Type: Rolls-Royce 250-C47M. Aircraft Location After Event: ZZZZDescription of the Occurrence. During a private VFR flight in Location A; the aircraft experienced multiple in-flight flameouts under normal operating conditions.Two flameouts occurred during level cruise flight over Location B; without any precipitation or freezing conditions present. A third flameout occurred during descent from FL100 into Location C. All flameouts resulted in momentary loss of engine power; though power was recovered spontaneously or through pilot action in each case. No caution/warning indications preceded the events; and engine parameters were within expected limits up to the time of each event.Post-Flight Investigation. Following the incident; the aircraft was landed safely and grounded at ZZZZ. Maintenance personnel performed an engine inspection and discovered the fuel nozzle had become detached and migrated inside the engine. The nozzle was found crushed/deformed; lodged ; squeezed just upstream of the Stage 1 turbine wheel. Clear evidence of internal engine damage was noted. Residual fuel smell and abnormal startup performance (longer spool-up times; excess fuel burn; rich exhaust) had been noted in prior flights and informed Maintenance. This confirms a mechanical engine failure due to fuel system/component separation; which directly caused the in-flight flame outs.Operational and Safety Impact. The nature of the failure--multiple flameouts and a detached fuel nozzle inside the turbine section; constitutes a serious flight risk; with potential for engine loss or total engine failure. Flameouts at cruise and during descent presented high workload and emergency risk for the pilot; particularly in mountainous terrain.Action Taken. The aircraft was grounded immediately following the event. Aircraft log was noted after landing; with issues. Maintenance findings were documented with photographs and technical notes.