A "credible security threat" caused an Alaska Airlines flight from Everett's Paine Field to be diverted to Portland on Sunday, the airline confirmed to KING 5. The threat was related to an off-duty pilot who "unsuccessfully attempted to disrupt the operation of the engines," according to the airline. The captain and first officer quickly responded, Alaska said, and engine power was not lost. The flight, which was being operated by Horizon Air, was en route from Everett to San Francisco when the incident occurred. Alaska Airlines owns Horizon. Read more: https://www.king5.com/article/news/local/public-safety/credible-security-threat-paine-field-flight-diverted/281-226138f9-a83b-4ffc-a578-73e654c12f66