PA-28 Cherokee/Archer/Dakota/Pillan/Warrior
Flight Crew Instrument; Flight Crew Private
Flight Crew Last 90 Days 30; Flight Crew Type 70
Situational Awareness
Airspace Violation All Types; Conflict Airborne Conflict; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy
Flight Crew Took Evasive Action
Human Factors
I was flying a Piper Archer under visual flight rules.  I was familiar with the area. I was flying south around highway 55; about 3-4 miles west of 494 near Wayzata; Minnesota.  This area is under the 4000 ft shelf of the MSP class Bravo.  I was tuned to FCM Tower as I already made my 10 mile out call.  The wind was out of the east.  I received a traffic warning from my G1000.  It pointed out traffic to my right at about 4 or 5 o'clock and 300 feet above me.  I turned and looked over my shoulder to see an airliner heading right for me with his lights on.  At that moment I would guess the airplane was less than 1 mile away from me.  I put my plane in an emergency dive. I pulled up at about 2;500 feet MSL. By this time the plane was passing to my rear and left.  I returned and landed at FCM but was quite shaken up. I looked up the plane on [an app] which shows a 737-800 flying in the same area at the same time.  The track shows the plane descending to 3;900 ft MSL a couple miles prior to entering the 3000 foot ring of the Class Bravo.  I was not on flight following at the time; but my trip was recorded in [the app].  My conclusion is the actions of the flight crew in the other plane caused them to leave the protected space of the Class Bravo.  This caused a near miss with another aircraft; and caused [me] to do emergency evasive maneuvers over a highly populated area.
Piper Archer pilot reported an airborne conflict with a B737-800 that had apparently descended below the MSP Class B airspace on arrival to MSP.