Cessna 152
Flight Crew Private
Flight Crew Last 90 Days 36; Flight Crew Total 85; Flight Crew Type 47
Training / Qualification; Time Pressure; Situational Awareness
Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Executed Go Around / Missed Approach
Environment - Non Weather Related; Human Factors
I was conducting a personal scenic flight with a passenger; one of my first since getting my Private Pilot License. We were returning to BFI; which is much busier than the airport where I received my primary training. I was more nervous than normal on the flight due to the passenger. About 20 minutes before arrival; my passenger informed me they were hungry and wished to expedite our return. Wanting to keep my passenger happy; I increased my airspeed. This definitely distracted me from me during a critical phase of flight.When I was about 4 miles away from the airport; I was given clearance to land; and was told there would be a departing B787; and 'Caution Wake Turbulence'. After acknowledging the clearance; I wondered when exactly the B787 would be departing or had departed. I called BFI Tower back; who simply told me there would be a departing 787 from the parallel runway; but didn't tell me when exactly it was/had departed.At that point; I considered asking for a 360 for spacing; but I decided not to; primarily because I didn't want to cause trouble to the Controller or other aircraft. I also didn't want to upset my passenger [who] was eager to get back; and didn't want to seem nervous about the wake turbulence. At this point; I was about 2 miles away; and didn't see the aircraft; and hoped it already had departed.When I turned base; I saw the B787 on its takeoff roll on the parallel runway. Due to the runway design; I knew its rotation point on the longer runway would be very close to my touchdown point. In retrospect; I should have considered that the light crosswind (about 3 knots towards my runway) would make a wake turbulence encounter more likely. I didn't consider going around.I steepened my approach angle and increased my airspeed slightly in case of an encounter. By the time I was on a 3/4 mile final; I estimate the B787 had departed approximately 1 minute before. When I was about 400 FT AGL I experienced a sudden left roll and downward pitch; and immediately applied opposite aileron. I estimate the maximum roll was about 30 degrees to the left. The sudden roll forced me off centerline; towards the parallel runway. I then immediately began a go-around. Although I was quite shaken; I landed uneventfully. In my opinion; my inexperience was a major factor in this incident. I am a very new private pilot (less than a month). Although I learned about wake turbulence during my primary training; I never actually experienced a situation where wake turbulence might be a factor. I don't think I understood the danger it posed. My inexperience also made me reluctant to request additional spacing from ATC; even though at the time I knew it was a good idea. The passenger wanting to return also made me reluctant to delay. I also wish my primary training had placed more emphasis on situations where it is appropriate to be more assertive with ATC to achieve higher safety. I also think my primary training should have emphasized practical wake turbulence avoidance more; especially since I operated at an airport where wake turbulence was never an issue.Although the fault was primarily mine; I think the Controller could have assisted by providing more information about when the aircraft would be departing; and asked if I wished to conduct a 360 or other spacing maneuver.
C152 pilot reported encountering wake turbulence at 400 FT AGL from a B787 departing on a parallel runway.