An E-135 flight crew encountered wind shear conditions on final approach; which resulted in a momentary stick shaker. They regained control; adjusted their approach speed; and landed without further incident.
Synopsis
An E-135 flight crew encountered wind shear conditions on final approach; which resulted in a momentary stick shaker. They regained control; adjusted their approach speed; and landed without further incident.
Narrative
An approach to Runway 27L at ORD was being flown with the autopilot on; flaps 22; in visual daylight conditions; I was pilot flying. The winds were steady at first; but during the last part of the approach (inside the marker; fully configured) they suddenly became erratic surging headwind gusts. At about 1;000 AGL; a strong; steady headwind gust was encountered; power was applied to maintain glideslope and airspeed. The pitch limit indicator appeared green; then amber; then momentarily red; setting off the stick shaker for a split second causing the autopilot to disconnect. The remaining approach was flown by hand using judicious pitch trim; and throttle inputs resulting in N1 readings between 74% and idle to try and maintain target airspeed. Target was originally REF+10; but was increased another 10;000 by the Captain after the large gust. The resulting landing was on speed; on profile; and safe.There have been times in the past when I have flown approaches in wind gusts with the autopilot on; although the wind gusts were not very severe. The event in this report contained a wind gust that was just sudden and strong enough to activate the stick shaker and cause the autopilot to disconnect. After experiencing this event; I now know the point where the shaker will activate in wind gusts and will hand fly the airplane before getting into that condition.
Second reporter narrative
The First Officer/pilot flying responded correctly and recovered the aircraft to normal and safe seed. We continued the visual approach and conducted a landing without further incident.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.