Date: 201706
Local time of day: 1801-2400
Location: MDW.Airport, IL
Flight conditions: VMC
Weather elements / visibility: 10
Light: Daylight
Aircraft: Cessna Single Piston Undifferentiated or Other Model
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Personal
Flight phase: Taxi
ATC / advisory: Ground MDW
Second aircraft: Large Transport; Low Wing; 2 Turbojet Eng
Reporter organization: Personal
Reporter function: Single Pilot
Reporter qualification: Flight Crew Instrument; Flight Crew Private
Second reporter function: Pilot Not Flying
Anomaly: Conflict Ground Conflict; Critical; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway; Ground Incursion Taxiway
Detector: Person Flight Crew
When detected: Taxi
Contributing factors: Human Factors
Primary problem: Human Factors

Narrative: Crossed hold short line though I read back the clearance to cross but must have been another aircraft had asked for progressive taxi; will not cross any hold short lines in future unless positive my aircraft has been cleared when in doubt hold and clarify.


Second narrative: This report is to record events witnessed by us while taxiing to the gate after landing in MDW. We had just landed 22L in MDW; had cleared the runway on Y2; and were taxiing to the gate via Y. We were cleared by Ground to continue taxiing via Y to the gate; and a Cessna [Aircraft X] from the right would give way to us. As we approached F; we got sight of the Cessna taxiing to the northwest on F. If I remember correctly; Ground then told him to give way to Company and follow us on Y. I could see these last two letters on his fuselage; but couldn't make out any more of his tail number because the baggage door on the aft portion of his fuselage was open; obscuring the number. As he approached Y; he didn't slow down; so my Captain slowed us to a stop so we didn't run into him. He continued straight ahead; across Y and toward Runway 22L not slowing down. This really got our attention because there was a Company 737 [Aircraft Z] just touching down on 22L. After crossing Y; the Cessna continued across the hold short line as the 737 was fully committed to his landing. The wing spoilers were up and he had been on the ground long enough to activate his reversers; so he would not have been able to go-around. The Cessna and the 737 were on a collision course. Seeing he didn't have any awareness of where he was and apparently didn't see the 737 bearing down on him; I instinctively starting yelling; 'Stop! Stop! Stop!' over Ground frequency. He fortunately stopped his aircraft just short of the runway edge line and calmly asked; 'You want me to stop right here?' just as the 737 crossed right in front of him on its landing roll-out. Ground responded and cleared him to do a 180 and taxi down F to hold short of K. He turned around and started taxiing southeast on F. He crossed Y and continued right on past K; not complying with that hold short clearance. Ground then told him to hold his position and copy a telephone number for a possible Pilot Deviation. We continued on at that point to the gate. I continued to hear Ground talking to him apparently having more problems with taxi clearances.It is my belief that if the Cessna had not stopped when he did; he would have been clipped by the left wing of the 737 or worse; the engine.


Synopsis: GA Pilot and air carrier pilot reported a taxiway and runway incursion at MDW which almost resulted in a collision.