EMB ERJ 145 ER/LR
Conflict Ground Conflict; Critical
Flight Crew Took Evasive Action
Human Factors; Procedure; Airport
Taxiing from ramp to 22L; we were eastbound on Taxiway B; initially following an MD80. The MD80 made a turn onto parallel Taxiway A; was paralleling our taxiway in the same direction (eastbound); when the MD80 made a right turn onto Taxiway F and began the quick left turn back onto B (creating a conflict between us and the MD80 at the intersection of B and F). My Captain was alert and slammed on the brakes (enough to cause my head to almost hit the instrument panel). Just after we stopped; the MD80 also stopped; but continued after a brief moment; and it was clear the potential of collision was clear (however where they stopped they were directly in our path on Taxiway B). No contact ever occurred; but was imminent and would have occurred within the next 2-5 seconds had action to stop not been taken by my Captain. Both aircraft were taxiing at normal speeds. We were just given an early frequency change to Tower; thus the MD80 was on Ground Control and we were on Tower (different frequencies). As the First Officer my head was down; changing frequencies and verifying departure frequency set in standby. I believe the general lack of oversight and the sometimes-lack-of-exercise-of-control on the ground at ORD by Ground Control are contributing factors. Sometimes aircraft are left to their own devices about which way to taxi (ex Ground Control issues instruction 'taxi to park' with no specific routing). This common lack of control may have given the pilot of the MD80 the idea that they could taxi any way they wanted; or could easily correct their own mistake (as it appeared they made a mistake by exiting B early and then attempting to return to it). Another threat in this case was the early frequency change to Tower given to us by Ground Control; resulting in us and the MD80 being in close proximity; but on different frequencies. Extreme caution must always be used in ORD.
EMB145 First Officer describes a ground conflict that developed during taxi for takeoff with the reporter on ORD Tower frequency and the conflicting MD80 inbound to the gate on Ground Control frequency.