ACR MLG ENGINE FLAME OUT IN HEAVY RAIN. AFTER RELIGHT ACFT DIVERTED TO ALTERNATE. EXTENSIVE TURBINE DAMAGE DISCOVERED ON POSTFLT INSPECTION.

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FLYING OVER ENO VOR FL180; 250 KTS. HAD IGNITION ON FLT; NACELLE HEAT AND WING ANTI-ICE ON. TAT +2.4. WX WAS LIGHT TO OCCASIONAL MODERATE RAIN WITH LIGHT TURB. SUDDENLY HIT UNSEEN; VERY HVY RAIN. #1 ENG FLAMED OUT ABOUT 7-10 SECS LATER. F/O WAS FLYING ACFT. HAD HIM TURN W AWAY FROM ANY POSSIBLE WX. NOTIFIED CENTER OF PROB. ENG DID NOT RESTART ON ITS OWN. STARTED APU AND ATTEMPTED STARTER ASSISTED START. NO AVAIL. WENT TO WINDMILL START CHKLIST. LOWERED NOSE TO OBTAIN PROPER SPD. ENG RESTARTED; ALTHOUGH NOT STABILIZING FOR 2-3 MINS. FIRST ELECTED TO GO TO EWR; BUT DETERMINED WILMINGTON; DE; WAS CLOSER. WITH COORD FROM ZNY WE GOT VECTORS TO VISUAL; RWY 9 AT WILMINGTON. LNDG WAS UNEVENTFUL; AND NO EVAC WAS NECESSARY. BECAUSE WE WERE AN INTL FLT; WE HAD TO ARRANGE WITH CUSTOMS AND IMMIGRATION TO BUS OUR PAX AND CREW 100 MI TO EWR. ENG; UPON WALK AROUND AFTER LNDG; APPEARED TO HAVE SUFFERED SOME EXTENSIVE TURBINE SECTION DAMAGE. AN IRREGULARITY RPT AND A RPT TO THE NTSB HAS BEEN SENT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING: THE ENG DAMAGE WAS CAUSED BY THE OUTER CASE SHRINKING DUE TO SUDDEN TEMP CHANGE AND GRINDING OFF THE TIPS OF THE TURBINE BLADES. APPARENTLY THE CASE WILL CHANGE DIAMETER FASTER THAN THE BLADES CAN CHANGE IN LENGTH. A FULL NTSB INVESTIGATION HAS BEEN MADE OF THE INCIDENT; BUT NO RPT HAS BEEN ISSUED. THE PIC IS STILL OFF FLT PENDING THE NTSB REPORT AND ANY SUBSEQUENT FAA ACTION. RPTR SAYS THERE HAVE BEEN 14 ENG FLAMEOUTS IN HVY RAIN WITH THIS ENG TYPE. ACFT RADAR RETURN DID NOT SHOW THE HVY PRECIPITATION THEY ENCOUNTERED AND AFTER ENG RESTART THE ENG WAS ROUGH ALTHOUGH THEY WERE ABLE TO PULL PARTIAL PWR. THEY DID NOT FLY THROUGH ANY HAIL OR HAVE ANY HAIL DAMAGE. WHILE ATTEMPTS WERE BEING MADE TO RESTART THE ENG; THE GND PROX WARNING BEGAN SOUNDING; 'TERRAIN; TERRAIN; PULL UP.' ALL 3 ALTIMETERS SHOWED 18000'. ATC RPTED LOSING US ON RADAR SO I PULLED UP AND CLBED TO 20000' W/O DELAY. WE WERE THEN REACQUIRED ON RADAR WITH MODE C SHOWING OUR ALT.