Air carrier flight crew reported landing in turbulent conditions resulting in a wing tip strike.
Synopsis
Air carrier flight crew reported landing in turbulent conditions resulting in a wing tip strike.
Narrative
Going into ZZZ late at night on Date; the tower was closed; and on the surface the winds were about 07011G20. We decided to back up our visual approach with the ILS to [Runway] XX. The OAT was 11C; so we didn't have any anti ice on at that time. The winds aloft were showing a quartering tailwind once we were established. Because of that; I intercepted in white needles and slowed to 200 KIAS. I was fully configured prior to the FAF. On final the airplane was crabbed into the wind; and I disconnected the autopilot around 700 feet AGL. Everything felt normal and seemed fine. I was told that I was Vref +10 at 100 feet; and I began a normal power reduction. I was trying to keep some power in slightly longer than normal just in case the wind shifted; because it was gusty and bumpy. I was at idle thrust at roughly 50 feet; maybe just below that. The airplane yawed due to the wind; and I corrected to maintain centerline. As I was flaring; the right wing dropped sharply. It felt like the wing tip just stopped producing lift; that's how sharply it dropped. It was a right crosswind; maybe slightly quartering; and the right main touched down first. The landing felt firm with how quickly the wing dropped. Leading up to when the wing dropped; I felt confident in it being a safe landing. I was very surprised by how quickly the wing dropped. I've never felt the airplane do anything like that before. We never had any indications or warnings of wind shear or a stall. The Captain took control of the aircraft after touchdown. No customers or crew members were injured. We both conducted the post flight walk around; and that's when we saw that we had a wing strike. The strike happened on the under side of the wing by the tip.Something caused the right wing to drop abruptly during the flare. I have ideas as to what happened; but I'm not sure. We could've gotten wind shear; we could've had a random gust or downdraft too. My best guess is that it could've been any number of these. The east side of the airport is where the control tower; some hangers; and trees are. With the winds being out of the east it makes me wonder if we had a weird gust of wind mixed with some mechanical turbulence. I'm not certain what caused the wing to drop; I just know that the right wing dropped very abruptly at about 10 feet.
Second reporter narrative
This is the ZZZ METAR approximately nine minutes after the time of the incident. ZZZ [Date and Time] AUTO 07011G20KT 10SM OVC095 01/M03 A2991 RMK AO2 SLP139 T00111028 400391044 Prior to departing for ZZZ while sitting at the gate in ZZZ1 we received the METAR for ZZZ and discussed which runway to use. Since the winds were almost a direct crosswind; we decided to use ILS [Runway] XX. We felt that provided the safest option at night with both lateral and vertical guidance. We briefed it at the gate and setup the frequency. While approaching ZZZ Runway XX we received the METAR and elected to begin our approach at the 'ZZZZZ' fix on the extended centerline of Runway XX. Because of the strength of the winds aloft; we slowed early and elected to have the aircraft join in 'white needles'. After joining the localizer in 'white needles' we switched to 'green needles' and allowed the autopilot to continue down to about 500 feet AGL. While descending; I commented that it would be OK to call for a go-around if anything didn't seem correct. At 100 feet we were at Vref+12. Because of the crosswinds and turbulence I was happy with the extra speed for controllability. The aircraft progressed from 50 to 10 feet without anything unusual occurring and Name transitioned smoothly from a crab to a slip for landing. Suddenly; right before touchdown; the aircraft rolled rapidly to the right into the upwind wing. FO corrected left and immediately landed. The airplane was yawing hard right and I called; 'My aircraft'. FO released the controls and I brought the aircraft to a slow taxi back on the centerline. As a general rule; I always follow-along with my FOs (First Officers) on the yoke and rudder pedals during take-off and landing. The aircraft rolled so rapidly to the right; that I could not catch it in time either. Prior to landing we did have a discussion about the proper use of ailerons during a crosswind. I did this as a precaution because I have noted that several FOs either do not use ailerons or use them improperly during take-off and landing. I didn't have any indications of a wing strike; but due to the roll rate and angle I thought it was a possibility. During post-flight inspection we noted a tip strike on the right fiberglass fairing. We did not receive a stick shaker/pusher or a wind-shear warning. I also don't think the continuous ignition automatically armed. Neither one of us noted that event. I think we were below 10 feet so the wind-shear warning system would have been suppressed. I think this may have been an unfortunate wind-shear event. I consulted our flight attendant to ask if any of the passengers had mentioned anything or were injured. She told me that the landing was a bit rough but none of the passengers commented further and no one was injured. Immediately after the event I contacted the duty pilot and asked for advice. He told me to write the wing strike up and to contact Maintenance Control. I accomplished both of those items. Additionally; there were no PIREPs and the Tower was closed. I don't know what the exact cause of the incident was. We did not get a shaker or pusher so I don't think the wings alpha was an issue unless a gust disrupted airflow over the wingtip. I felt that there was nothing unusual about the aircraft's attitude; speed or position approaching the runway. We did not get a wind-shear alert; but the wind-shear alerting system would have been suppressed that close to the ground. The aircraft rolled right faster than I have ever seen it do that and I really don't know why. The best way to describe the rolling moment is to compare it to the way a GA aircraft breaks when doing spin training. I have been flying the aircraft for about 8 years and I have never had anything like this happen. Both Name and myself are not new to the airplane and I didn't note any deficiencies in his airmanship on the previous leg. I am of the opinion that this event was a windshear induced event. I don't know what could have been done to prevent this from happening again.
Source: NASA Aviation Safety Reporting System (public domain). Reports are voluntary submissions and are not verified by NASA.