Date: 201401
Local time of day: 1801-2400
Location: ORD.Airport, IL
Aircraft: Regional Jet 700 ER/LR (CRJ700)
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Flight phase: Descent
Airspace: Class E ORD
ATC / advisory: TRACON C90
Aircraft component: Altimeter
Component problem: Improperly Operated
Reporter organization: Air Carrier
Reporter function: Captain; Pilot Flying
Reporter qualification: Flight Crew Air Transport Pilot (ATP)
Human factors: Human-Machine Interface; Confusion; Communication Breakdown; Situational Awareness
Second reporter function: Pilot Not Flying; First Officer
Anomaly: Aircraft Equipment Problem Critical; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Air Traffic Control
When detected: In-flight
Result: Air Traffic Control Issued Advisory / Alert; Flight Crew Overcame Equipment Problem; Flight Crew Returned To Clearance
Contributing factors: Aircraft; Human Factors
Primary problem: Human Factors

Narrative: We were descending via the BULLZ6 STAR into ORD and were handed off to Approach. The First Officer checked in with our altitude descending through (approx 13;800 FT I think) and said 'Descending via BULLZ6;' as well as ATIS. The Controller acknowledged our check-in; stated the current ATIS (I noticed the ATIS identifiers were way off); expect Runway 27R and asked what the assigned altitude we were descending to. The First Officer read back everything except the assigned altitude. I told him she wanted our assigned altitude; which I thought was unusual on a 'descend via' clearance on a STAR. Someone else checked in at this time and after acknowledging the check in; the Controller queried us again on our assigned altitude (11;000 FT on the STAR); the First Officer replied '11;000.' At this point; we were leveling off. After a minute or so; she asked us again what our assigned altitude was and once again the First Officer stated '11;000.' At this point she said the ORD altimeter is 29.62 and she was showing us at 10;400. We had set our altimeters to 30.23 at FL180! I immediately corrected the altimeter and climbed back up to 11;000. I had gotten the altimeter setting from the ATIS printout that was laying in the usual spot; between the flap handle and thrust levers. When looking at the ATIS; I failed to realize that it was the old ATIS from our departure airport. This also explains why the current ATIS was [different than what we checked on with]. Once we were back to 11;000 the Controller verified our mode C and the flight continued uneventfully.This occurred because I didn't verify the ATIS printout I was looking at was the correct one for the airport we were going to. I was complacent in assuming the current; correct ATIS would be in that spot. We also failed to record the altimeter setting when the Center Controller had us descend below FL180. I need to be more vigilant when looking at ATIS printouts. Also; record the altimeter setting received from Center when they descend us below FL180. I think it could have been corrected sooner if the Approach Controller would have said our altitude was off sooner. She queried us three times what our assigned altitude was; instead of saying our altitude was not matching what she is seeing.


Second narrative: Departure airport altimeter was 30.23 while local setting was 29.62.


Synopsis: A CRJ-700 flight crew descended below their cleared altitude when they set their altimeters to the pressure setting at their departure airport passing 18;000 MSL. ATC's initial inquiries as to their 'assigned' altitude failed to alert them as to their error. The issue was resolved only after ATC stated she showed them 600 FT low and advised of the correct altimeter setting.