Air carrier pilots reported encountering wind shear on final approach.
Synopsis
Air carrier pilots reported encountering wind shear on final approach.
Narrative
We were arriving into IAH and deviating around thunderstorms off of the HTOWN3 arrival for the ILS 8R. After briefly proceeding back direct WDLNS on the arrival ATC began vectoring us around additional isolated thunderstorms for the approach and began descending us in preparation. Houston Approach eventually gave us an intercept and approach clearance with a descent to 4000ft to join final. We then descended and maintained 4000ft and 180 knots as assigned by ATC. We heard the traffic ahead of us report an acceptable ride. We then heard them report a 30 knot gain of airspeed a few moments later. After a quick dialog between xxx and I; I notified ATC we would be slowing to 170 knots. xxx then slowed to 170 knots and commanded the gear down to which I executed. A few seconds later we entered a shear although in our case the airspeed began to aggressively bleed off. I believe it was about a 45 knot loss. With the automation engaged and increasing thrust the airplane was able to stay at 4000 ft; I believe we were still about 15 miles from IAH. As the airspeed bled off almost instantly and with the previous report of a 30 knot gain I was shocked and anticipating the speed to recover instantly to which it did almost as soon as I vocalized the speed loss to xxx . To which his hand was already moving toward the thrust levers. At this time however the speed was back at 170 knots and I reported the airspeed loss to ATC. Around 3500 ft we broke out of the clouds and had a clear sight of 8R as well as the entire IAH airport environment. As soon as we broke out we were in calm atmospheric conditions in accordance with what the airfield was reporting at the time. We landed and taxied to the gate without incident.
Second reporter narrative
We were cleared to descend via the HTOWN3 arrival into Houston and almost immediately asked for lateral deviations to avoid isolated cells near the arrival course. After several turns we were able to rejoin the lateral course of the HTOWN and continued our descent. After Houston approach vectored us around the worst of the weather they continued to descend us to 4000 (I recall) and gave us a vector to join the 08R ILS. We maintained 4000 and 180 knots as assigned by ATC. The ride was reported as acceptable by the traffic we followed. Shortly after this report the same aircraft reported a gain of 30knots and I slowed to 170 knots and commanded gear down (still level at 4;000 feet). Shorty after this the airspeed aggressively bled off by at least 40 knots; all while altitude remained pegged at 4000 feet. Almost before I could move my head forward on the thrust the auto thrust aggressively added power and we were back to 170 knots in what seemed like a few seconds; with speed brakes stowed for the entirety (still level 4000 feet). At this point we joined glide slope was and 'we reported the airspeed loss to ATC'. At approximately 3;500 feet we broke out to clear view of 08R in relatively calm conditions. The airfield reported no hazardous conditions except a light cross wind and we landed uneventfully and taxied to the gate.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.