Narrative:

Crew was on downwind for visual approach xxr at ZZZ. First officer was high minimums with approximately 45 hours in the 737. Due to this; ca (captain) was required to conduct the landing. A thorough brief and discussion took place at cruise and it was decided first officer (first officer) would fly the approach and when before landing checklist was complete and aircraft was stable aircraft control would be exchanged for ca to complete the landing. ATC gave a base vector and traffic call for aircraft going to xxl. Crew visually acquired traffic and was told to maintain visual separation and were subsequently cleared for the visual approach. First officer disengaged the autopilot and began calling for configuration changes. At approximately 2000 ft AGL the aircraft was configured with gear down and flaps 15 at 180 KIAS. Around this time TCAS produced a traffic traffic call based on the previously acquired traffic going to xxl. The alert momentarily caused a distraction to both pilots. The first officer continued slowing the aircraft and at around 170 KIAS called for flaps 30 and the landing checklist. Aircraft speed continued to slow and approach target speed of approximately 154 KIAS. At no time after flaps were moved to 30 was aircraft speed increased above 170 KIAS and definitely did not approach flaps 30 over speed of 175 KIAS. The landing checklist was accomplished and the first officer observed the ca moving the flap handle to the 30 position. However; due to flying the visual approach and being distracted by parallel traffic the first officer did not crosscheck and verify the flap gauge was reading 30. The ca called 'flaps 30 green light' and visually saw flap gauge indicating 30. Shortly after this the 1000 ft call was made by the ca and controls were exchanged as previously briefed during the arrival briefing. The first officer made a 500 foot call and ca replied with stable. At approximately 150 AGL the GPWS began issuing a too low flaps aural warning. Both first officer and ca confirmed the flap handle was in the 30 position and that le ext green light was illuminated. The aircraft was stable on glide slope; lateral course; and airspeed. Around 100 to 50 AGL it was finally discovered that the flap gauge was reading 25 and not 30. By the time this configuration was verified by both pilots the ca had already begun the landing flare and aircraft was about to touchdown. Due to confusion; workload management and the extremely low altitude of the aircraft the crew determined the best course of action was to continue the landing. Upon touchdown the speed brakes auto deployed; auto brakes engaged and the aural warning silenced. After clearing the runway the flap handle was moved out of the 30 detent to up and the flaps properly tracked. The flap handle was then moved to the 30 detent and flaps properly tracked. Flap handle was finally moved up again and after landing low was completed. Crew taxied to gate and shutdown aircraft normally.

Google
 

Original NASA ASRS Text

Title: B737 flight crew reported a too low flaps GPWS warning at 100 ft AGL.

Narrative: Crew was on downwind for visual approach XXR at ZZZ. First Officer was high minimums with approximately 45 hours in the 737. Due to this; CA (Captain) was required to conduct the landing. A thorough brief and discussion took place at cruise and it was decided FO (First Officer) would fly the approach and when Before Landing Checklist was complete and aircraft was stable aircraft control would be exchanged for CA to complete the landing. ATC gave a base vector and traffic call for aircraft going to XXL. Crew visually acquired traffic and was told to maintain visual separation and were subsequently cleared for the visual approach. FO disengaged the autopilot and began calling for configuration changes. At approximately 2000 ft AGL the aircraft was configured with gear down and flaps 15 at 180 KIAS. Around this time TCAS produced a TRAFFIC TRAFFIC call based on the previously acquired traffic going to XXL. The alert momentarily caused a distraction to both pilots. The FO continued slowing the aircraft and at around 170 KIAS called for flaps 30 and the landing checklist. Aircraft speed continued to slow and approach target speed of approximately 154 KIAS. At no time after flaps were moved to 30 was aircraft speed increased above 170 KIAS and definitely did not approach flaps 30 over speed of 175 KIAS. The landing checklist was accomplished and the FO observed the CA moving the flap handle to the 30 position. However; due to flying the visual approach and being distracted by parallel traffic the FO did not crosscheck and verify the flap gauge was reading 30. The CA called 'flaps 30 green light' and visually saw flap gauge indicating 30. Shortly after this the 1000 ft call was made by the CA and controls were exchanged as previously briefed during the arrival briefing. The FO made a 500 foot call and CA replied with stable. At approximately 150 AGL the GPWS began issuing a TOO LOW FLAPS aural warning. Both FO and CA confirmed the flap handle was in the 30 position and that LE EXT green light was illuminated. The aircraft was stable on glide slope; lateral course; and airspeed. Around 100 to 50 AGL it was finally discovered that the flap gauge was reading 25 and not 30. By the time this configuration was verified by both pilots the CA had already begun the landing flare and aircraft was about to touchdown. Due to confusion; workload management and the extremely low altitude of the aircraft the crew determined the best course of action was to continue the landing. Upon touchdown the speed brakes auto deployed; auto brakes engaged and the aural warning silenced. After clearing the runway the flap handle was moved out of the 30 detent to up and the flaps properly tracked. The flap handle was then moved to the 30 detent and flaps properly tracked. Flap handle was finally moved up again and after landing low was completed. Crew taxied to gate and shutdown aircraft normally.

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.