Regional Jet 200 ER/LR (CRJ200)
Flight Crew Air Transport Pilot (ATP)
Situational Awareness; Communication Breakdown
Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Inflight Event / Encounter CFTT / CFIT
Flight Crew Became Reoriented; Flight Crew Took Evasive Action; Flight Crew Returned To Clearance
Human Factors
The aircraft was being vectored for a visual approach. At 10;000 feet the pilot monitoring asked for a lower altitude. The approach controller then cleared the aircraft from 10;000 feet to 4;000 feet. The pilot flying then began the descent from 10;000 feet to 4;000 feet. While descending the approach controller cleared the aircraft to a lower altitude. The transmission was blocked; however the pilot monitoring responded with a 'Descend to 3;500 feet' This was corrected by the approach controller as 2;500 feet not 3;500 feet. As the descent continued in visual conditions both pilots remarked that the aircraft felt lower than its indicated altitude. The pilot flying reduced the descent rate of the aircraft and both pilots verified the final approach fix and their assigned altitudes matched. Soon after the pilot flying disconnected the autopilot and increased thrust to climb with both pilots realizing the altimeters were incorrectly set. Moments later the approach controller informed the aircraft of a low altitude alert and to climb immediately. Misinterpreting an altimeter setting.Some of the things that could be incorporated to avoid a recurrence of the event is to ask for the full read back if a call is blocked. Another thing to make the altimeter setting stand out is to circle the altimeter setting on the ATIS and to write it on a scratch piece of paper. Finally making sure to repeat the altimeter setting back to the controllers could help mitigate this issue.
CRJ-200 First Officer reported receiving a low altitude alert from ATC on approach to TUL about the time they realized their altimeters were not properly set.