What was found
THE PILOT REPORTED THE HEATER HAD STOPPED DURING FLIGHT. AFTER RETURNING TO THE MAINTENANCE SHOP THE HEATER WAS TROUBLESHOT AND INSPECTED. FOUND THE HEATER FUEL PUMP HAD MALFUNCTIONED AND HAD CAUGHT ON FIRE FOR A TIME. WERE ABLE TO SAY IT WAS ON FIRE BECAUSE OF THE BURN MARKS ON THE OUTSIDE OF THE PUMP HOUSING. HAVE ENCLOSED 2 PHOTOS TO SHOW THIS. HAVE TALKED WITH PUMP MFG TO DESIGN A NEW PUMP . PROBLEM IS WITH FUEL REGULATOR ING THE WINGS. THE REGULATORS SEEM TO NOT ALLOW ENOUGH FUEL TO GO THRU THEM TO KEEP THE PUMPS OPERATING CORRECTLY WHICH ALLOWS THEM TO OVERHEAT AND FAIL. (K)