You are correct. AS 717 is one of the most frequently delayed flights in the AS system. I don't know why this flight is so consistently late. On 8/30 the delay was due to Air Traffic Control. On flightstats.com, AS 717 is showing 19% on-time for June 15 through Aug 15. After arriving in SEA, the aircraft usually flies AS 358 SEA-BUR which is showing 17% on-time. Avoid these two flights if you want to arrive on-time!
http://www.flightstats.com/go/Flight...atusByRoute.do
Anyway, hope it's on-time for you.