(Portland, OR)  --  An Oregon woman is facing a felony threat charge after allegedly shouting death threats on a flight from Portland to Sacramento.  Southwest Airlines says 24-year-old Sandy native Valerie Curbelo became belligerent Saturday after being caught trying to smoke in the airplane bathroom.  After being ordered back to her seat, the airline says Curbelo started shouting death threats at flight attendants and passengers.  Police arrested her upon the plane's landing.