Cessna 402/402C/B379 Businessliner/Utiliner
Flight Crew Air Transport Pilot (ATP)
Situational Awareness
ATC Issue All Types; Inflight Event / Encounter Loss Of Aircraft Control; Inflight Event / Encounter Wake Vortex Encounter
Flight Crew Regained Aircraft Control; Flight Crew Took Evasive Action; Flight Crew Executed Go Around / Missed Approach
Procedure; Environment - Non Weather Related
Coming in on the visual 4L; I was 4 miles behind a heavy Airbus A340 on final for 4R. At 300 feet the airplane rocked and bounced wildly; and the airplane went into a right roll. I was able to recover the roll at what I can only estimate to be about 90 degrees. People were bounced out of their seats; and pinned against the right side of the airplane. I struggled to control the airplane; applying full left aileron and rudder to attempt to correct the roll. Finally I was able to straighten the aircraft. I executed a go around at full power. We came back into land on 4L without incident. I asked the passengers once in the air when we got leveled out; and twice on the ground if anyone needed any assistance. The only passenger that spoke up was a female who had previously had back surgery. She stated her back hurt and that she would need to take her pain medicine now. She also asked for a wheelchair which I already had plane-side for her. Wake turbulence from the heavy Airbus; plus a 15 knot crosswind; blew the wake right into my aircraft; thus causing it to become uncontrollable.
Reporter stated the big problem at BOS was the tendency for ATC to continue to use Runway 4L even in crosswind conditions that tend to 'trap' the preceding aircraft's wake in the approach path for the following aircraft to encounter. Reporter suggested using Runway 15 could alleviate some of the concerns.
C402 Captain reported his aircraft was rolled into a 90-degree bank from wake turbulence at 300 feet AGL on approach into BOS 4 miles in trail of an A340.