Narrative:

On final for the visual 34L into sea we were following a [widebody] being vectored for the approach to 34C. Being 5 miles behind the heavy jet; we were cleared for the visual and I even prudently asked for the separation and their speed to better adjust things on our end to avoid wake turbulence. Around 5-10 miles from the runway at approximately 2500-3000 ft; we experienced a roll upset from wake turbulence from the [widebody]. It was aggressive; but controllable. If I had to guess; the aircraft was quickly rolled to about a 20 degree bank. The event only lasted a couple of seconds before we corrected the upset and were easily re-established. The captain adjusted the glide path to sit even higher to the glide slope as to avoid the wake turbulence; but within the stable criteria. The rest of the approach and landing was uneventful and the landing and taxi to the gate routine. Upon reaching the gate and deplaning; one passenger stated 'thanks for not killing us' in a very rude disdainful tone. The second passenger asked if we dodged an airplane or birds. Neither were true. Due to the nature of the passenger concerns; I found it necessary to file an as soon as possible and crew report. After that the flight attendant-a informed us that the passenger didn't wear his seat belt even when instructed to. He was also the individual that stated his remarks to us. I also think that the [widebody] was high on his visual approach to 34C so it put the wake turbulence right at our altitude when we were flying a higher glide slope already; but it was dark and difficult to see the situation fully. I would suggest that the wake separation be increased for [widebodies]. Five miles was just barely adequate and any aircraft smaller might actually experience jet upset at a low altitude.

Google
 

Original NASA ASRS Text

Title: EMB-175 reported encountering wake turbulence on approach to SEA in trail of a widebody transport. Reporter recommended increased separation from this type aircraft.

Narrative: On final for the visual 34L into SEA we were following a [widebody] being vectored for the approach to 34C. Being 5 miles behind the heavy jet; we were cleared for the visual and I even prudently asked for the separation and their speed to better adjust things on our end to avoid wake turbulence. Around 5-10 miles from the runway at approximately 2500-3000 ft; we experienced a roll upset from wake turbulence from the [widebody]. It was aggressive; but controllable. If I had to guess; the aircraft was quickly rolled to about a 20 degree bank. The event only lasted a couple of seconds before we corrected the upset and were easily re-established. The Captain adjusted the glide path to sit even higher to the glide slope as to avoid the wake turbulence; but within the stable criteria. The rest of the approach and landing was uneventful and the landing and taxi to the gate routine. Upon reaching the gate and deplaning; one passenger stated 'thanks for not killing us' in a very rude disdainful tone. The second passenger asked if we dodged an airplane or birds. Neither were true. Due to the nature of the passenger concerns; I found it necessary to file an ASAP and crew report. After that the Flight Attendant-A informed us that the passenger didn't wear his seat belt even when instructed to. He was also the individual that stated his remarks to us. I also think that the [widebody] was high on his visual approach to 34C so it put the wake turbulence right at our altitude when we were flying a higher glide slope already; but it was dark and difficult to see the situation fully. I would suggest that the wake separation be increased for [widebodies]. Five miles was just barely adequate and any aircraft smaller might actually experience jet upset at a low altitude.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.