Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP)
Confusion
Aircraft Equipment Problem Less Severe
General None Reported / Taken
Aircraft; Chart Or Publication; Human Factors
We noted a difference in a published altitude on a missed approach when comparing the approach plate with the aircraft database. We briefed the ILS 31C approach to Chicago-Midway Airport. The missed approach instructions on the approach plate direct a left turn toward Peotone and an altitude of 2;100 (or below) until crossing IGECY. The LEGS page of the CDU displayed the IGECY altitude as '2100A.' [Although] our procedures should preclude an altitude deviation should a crew fly the missed approach; I believe the possibility exists. The [commercially provided] approach plate text would lead pilots to level off at 2;100. Should a pilot become busy with missed approach tasks and check the LEGS page for the correct altitude setting (rather than the printed approach plate); he/she could easily set the final altitude in the [MAP procedure] (2;600).
Commercial Captain reported a discrepancy between charted procedural altitude constraints on the MAP from the ILS Runway 31C at MDW and the constraints published in the aircraft's FMS database.