Date: 202104
Local time of day: 1201-1800
Location: ZZZ.Airport, US
Flight conditions: VMC
Aircraft: B737 Undifferentiated or Other Model
Operator: Air Carrier
Operating under: Part 121
Flight plan: IFR
Mission: Passenger
Flight phase: Final Approach
Airspace: Class B ZZZ
ATC / advisory: Tower ZZZ
Reporter organization: Air Carrier
Reporter function: Pilot Not Flying; First Officer
Reporter qualification: Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Human factors: Confusion; Communication Breakdown; Situational Awareness; Time Pressure; Workload
Second reporter function: Captain; Pilot Flying
Anomaly: Deviation - Speed All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Flight Deck / Cabin / Aircraft Event Illness / Injury; Inflight Event / Encounter CFTT / CFIT
Detector: Person Flight Crew
When detected: In-flight
Result: Flight Crew Overrode Automation
Contributing factors: Human Factors; Manuals; Procedure; Company Policy
Primary problem: Procedure

Narrative: The flight was about 30 minutes out and we started to have a medical situation. While we did not declare an emergency we were getting priority handling from ATC and short vectors to the ILS to include a rapid descent and a short downwind and base leg to final. Configuration was 190 Knots and flaps 10 to facilitate the rapid descent. Once on final; I called Tower and received clearance to land; the Pilot Flying called for Gear down and flaps 15; then flaps 25 on speed. At the time that we should have extended the flaps to 30; Tower called to ask if we had landing clearance yet. As Pilot Monitoring; I ended up talking to Tower. Either the Pilot Flying failed to call for flaps 30 or I didn't hear him call for flaps 30 due to the radio call from Tower. Between 600 and 700 feet the EGPWS (Ground Proximity Warning) for 'too low; flaps' went off and we immediately put the flaps to 30. Flaps had finished moving before the 500-foot call. The decision to continue to land was based on being on speed; on glide slope; length of runway available and the medical situation in the back of the aircraft. A normal landing was accomplished and the aircraft cleared the runway.


Second narrative: Flying with a medical situation. We did not declare an emergency but we're getting priority treatment for the ILS. Rapid descent with a turn on at the marker. We had gone to flaps ten to lose altitude quickly and slowed to about 190 knots. About 1 mile from the Final Approach Fix the First Officer called Tower and we were cleared to land I asked for gear down flaps 15 and started slowing further to flap 15 speed. Called for flaps 25. I remember looking to make sure we were slow enough and I am not sure if I called flaps 30 and he didn't hear it or if I didn't do it. The Tower had called us at the same time to tell us cleared to land again. Ran the checklist and just about when he got to flaps the too low flaps warning sounded at the same instant we broke out of the clouds. The First Officer put the flaps to 30. They were down about 500 feet. Completed checklist. I elected not to go around because of the medical situation and the 1X;000 foot runway and our speed was on target speed.  Normal landing and we exited as briefed.


Synopsis: B737 flight crew reported receiving a Ground Proximity Warning due to an incorrect flap setting but continued to land due to a medical emergency on the aircraft.