B737 flight crew reported an unstabilized approach in windshear alert conditions reported by ATC. The pilot flying continued the approach after speed increased by 10 knots at low altitude which caused the flaps to retract causing a EGPWS terrain warning for flaps in a non-landing configuration. The crew elected not to go around due to moderate rain at the far end of the runway; and landed safely.
Synopsis
B737 flight crew reported an unstabilized approach in windshear alert conditions reported by ATC. The pilot flying continued the approach after speed increased by 10 knots at low altitude which caused the flaps to retract causing a EGPWS terrain warning for flaps in a non-landing configuration. The crew elected not to go around due to moderate rain at the far end of the runway; and landed safely.
Narrative
On final for the ILS Runway XX into ZZZ the Tower reported wind shear alert of 15 knots on the departure end of Runway XX. We could see rain showers west of the end of Runway XX. The ATIS reported thunderstorms SW moving NE of the airport. The previous regional jet aircraft reported some speed fluctuations but landing normal. Below 1500 feet Tower reported wind shear alert at approach end of runway with winds at 14kts gusts to 23. I requested a side step to Runway XXL which was clear but was told unable due to aircraft on 2 mile final on Runway XXL. The First Officer continued the approach with the auto pilot off and was on speed 146+15=164 till about 300 feet when the airspeed started to increase with the power at idle and caused the flaps to retract to 25. We got the too low terrain call outs but continued to a normal landing as the rain showers had now moved towards the departure end of the runway and we did not want to perform a go around into that weather. It was a normal landing on speed. On roll out we encountered moderate rain by the exit taxiway.
Second reporter narrative
Rain showers and 15 knot loss of airspeed reported on departure end of Runway XX. We were on the ILS final to Runway XX. Winds were from the west at 14 gust to 23. Our 30 flap ref speed was 149 and our target speed was 164 We were on airspeed and glide path and stable at 500 ft. AGL. At 300 ft. AGL we picked up 10 knots of airspeed and I was countering by pulling power. Airspeed reached 175 and flaps blew up. We got warning for terrain too low because of flap position. I was back on airspeed of 164 and on glide path before runway threshold. Good landing on centerline and speed and normal rollout before rain showers on departure end of Runway XX.
More incidents for this aircraft family →
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.