PA-46 Malibu Meridian
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 38.3; Flight Crew Total 1779; Flight Crew Type 1206
Aircraft Equipment Problem Critical; Inflight Event / Encounter Weather / Turbulence
Flight Crew Overcame Equipment Problem; General Declared Emergency
Aircraft; Weather
This was a routine flight on an IFR flight plan. I had flown earlier that day at 17;000 uneventfully; along essentially the same route. On this return trip; initial clearance was for cruise at FL200. There were areas of moderate to severe precipitation along the route of flight that had moved in during the day; with forecast icing from 8;000 FT to FL200. This airplane is a PA46 conversion with a PT6A engine ('JetProp' by Rocket Engineering). Fuel resides in both wing tanks; each with a wing fuel pump that pumps via fuel lines into an 11 gallon header tank just behind the engine (warm conditions). Twenty-five minutes into the flight; while approaching an area of precipitation; I spoke with the Center Controller; who volunteered that recent flights had reported tops at FL200-210; I requested; and was cleared to FL220. Shortly thereafter; as I approached the area more closely; I requested; and was cleared; for an additional climb to FL240. I was IMC in thin haze/cloud conditions at -20 degree C; with anti-ice systems enabled; but no visible ice on wings or windshield. I was just leveling at FL240 when my engine flamed out; with zero fuel flow and near zero torque; and minimal fuel in the header tank. I switched off the autopilot and hand-flew to establish best glide while going thru the engine loss checklist; and reported to Center that I lost my engine and was gliding and would likely need an immediate descent. Over approximately the next 90 seconds; I switched tanks; switched on the emergency fuel pump; got some fuel into the header tank; and was able to restart the engine. I reached a minimum altitude of approximately FL226. I promptly began a climb back to 240; and informed Center that I had restarted the engine and was climbing back to my assigned altitude. The decision I then needed to make was whether to make a precautionary landing immediately; or continue. Below me at that time was 20+ thousand FT of ice-filled IMC; moderate to severe precipitation; with IMC or MVFR at nearby airports. The engine was now running smoothly; and the header tank was filling nicely. I could only imagine that there might have been some water in the fuel line which froze at altitude and fuel-starved the engine; at lower power settings (non-climb) and with the emergency fuel pump running; I had good fuel pressure and fuel flow. I thought I should descend to slightly warmer temperatures; but not into the icing region. I requested a descent to FL190; which was promptly granted. Closer to my destination; weather was good VFR; while in the area I was in there were multiple areas of IMC. Since the engine was stable; and there were plenty of fields nearby; I continued. A later Controller asked for fuel time remaining and souls on board - I answered '150 minutes and 3 people on board.' The remainder of the flight was uneventful. On landing; there was no water in the wing sumps or the engine sump; both wing fuel pumps were working normally. Nevertheless; the only explanation I have is possible fuel line ice that was bypassed by switching tanks and adding the pressure of the emergency fuel pump. I had sumped the fuel prior to my first flight that morning; but did not do so prior to this second flight of the day; since the plane had just been fueled; and I have read that it takes several hours for any water suspended in Jet-A to settle. In retrospect; I wish I had sumped prior to this flight; but I don't know if it would have prevented this occurrence.
A P46T pilot reported engine flame out at FL240 from what appeared to be fuel line icing.  Engine was restarted successfully and flight continued to destination.