B737-700
Flight Crew Air Transport Pilot (ATP)
Flight Crew Last 90 Days 234; Flight Crew Type 12550
Troubleshooting
Aircraft Equipment Problem Less Severe; Deviation - Speed All Types; Inflight Event / Encounter Weather / Turbulence; Inflight Event / Encounter Unstabilized Approach
Flight Crew Overcame Equipment Problem; Flight Crew FLC complied w / Automation / Advisory; Flight Crew Executed Go Around / Missed Approach
Aircraft; Weather
There were showers in the area with the ATIS reporting windshear advisories in effect. We had shifting winds down to about 500 ft. Although the winds we experienced during our landing flare were fairly steady; indicating a left quartering head wind of less than 15 knots. Turbulence varied from light to none throughout the approach below 2000 ft. On short final below approximately 500 ft the indicated airspeed was on target and steady. At approximately 150 feet or so; the airspeed remained steady and on target; but the stick shaker activated. Immediately and concurrently the Pilot Flying (F/O) and I reached for the thrust levers and called go-around thrust. The stick shaker silenced immediately as we climbed into a rain shaft ahead. I had the F/O continue to fly the aircraft while we were vectored around visually for another landing attempt. The cockpit was busy during the ensuing five minute pattern. At some point on base leg; during the second approach; I believe we were at flaps 5 and approximately 190 knots (?) We received an 'AIRSPEED LOW' audio warning that was (as far as I can tell) also erroneous. The ensuing landing was uneventful with no further warnings. I wrote up the aircraft using the words: possible erroneous stall warning and possible erroneous airspeed low warning. My gut feeling is that this aircraft was nowhere near a stall as I specifically remember seeing steady airspeed on target. And while in our base turn for our configuration; we should not have received the 'AIRSPEED LOW' warning. However; because of the weather conditions in the area; and how short-lived the whole event was; I am not certain of this. Thus my use of the words 'possible erroneous.'
[Report narrative contained no additional information.]
B737-700 flight crew reported a stall warning on short final which was determined to be erroneous. The crew executed a go-around and the subsequent landing was uneventful.