Air carrier flight crew reported an unstabilized approach due to a wrong flap setting.

Attributes
ACN	1764796
Time
Date	202010
Local Time Of Day	1801-2400
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	Landing
Flight Plan	IFR
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine Flight Crew Instrument
Experience	Flight Crew Last 90 Days 34 Flight Crew Total 2988 Flight Crew Type 2988
Person 2
Function	Captain Pilot Not Flying
Qualification	Flight Crew Instrument Flight Crew Air Transport Pilot (ATP) Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 11 Flight Crew Total 4905 Flight Crew Type 4905
Events
Anomaly	Deviation - Procedural Published Material / Policy Inflight Event / Encounter Unstabilized Approach

Narrative:

VMC approach to runway xxr at ZZZ at night; PAPI OTS. We were cleared the visual on a right base to the FAF. We flew the approach in LNAV/VNAV and showed on glidepath as we approached the turn to final. I had gear down; flaps 15 as we rolled out and was slowing to 180 knots. We both felt we were high although the pdi indicated only slightly above glideslope. We continued to configure the aircraft and called for the landing checklist. At 500; I called 'stable' when we realized the flaps were at 25 not 30. The captain selected flaps 30 and we continued the approach and landing without incident.this was the captain's third flight since march; I have flown more recently but it's been 3 weeks since my most recent flight.

Original NASA ASRS Text

Title: Air carrier flight crew reported an unstabilized approach due to a wrong flap setting.

Narrative: VMC approach to Runway XXR at ZZZ at night; PAPI OTS. We were cleared the visual on a right base to the FAF. We flew the approach in LNAV/VNAV and showed on glidepath as we approached the turn to final. I had gear down; flaps 15 as we rolled out and was slowing to 180 knots. We both felt we were high although the PDI indicated only slightly above glideslope. We continued to configure the aircraft and called for the landing checklist. At 500; I called 'stable' when we realized the flaps were at 25 not 30. The Captain selected flaps 30 and we continued the approach and landing without incident.This was the Captain's third flight since March; I have flown more recently but it's been 3 weeks since my most recent flight.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.