B737-900
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP)
Deviation - Altitude Excursion From Assigned Altitude; Deviation - Speed All Types; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Requested ATC Assistance / Clarification
Procedure; Environment - Non Weather Related
Intercepting the ILS 16R from heading 140; level 4;000; cleared for the approach. Speed assigned 170. Flaps 5 selected. At ILS GP and course intercept experienced wake turbulence. Brief stick shaker due to wake turbulence roll. Added power; recovered; stayed on ILS path and advised ATC of the encounter. Turned back on auto pilot/ throttle and shortly confirmed we were good to continue the approach. Landed without incident.Carry more speed above yellow bar; I could have configured to flaps 10.
Reporter stated wake encounter was stronger than they expected.
Wake turbulence was encountered during an ILS approach to Runway 16R in SEA after receiving approach clearance. Prior to GS intercept and maintaining 4;000 ft. at an issued speed of 170 knots; the aircraft unexpectedly jolted and rolled with varying pitch; momentarily activating the stick shaker due to the wake. Immediate recovery was conducted with a small variation in altitude while tracking the LOC path. After stabilizing the aircraft it was determined that sufficient distance remained to safely continue the approach and landing; which was conducted without incident. ATC was advised of the encounter. Maintaining extreme vigilance of wake turbulence is imperative at all times; even in the absence of an ATC transmitted 'wake turbulence' caution.
B737-900 Flight Crew reported encountering wake turbulence on descent into SEA.