Incident Overview
On February 23, 2016, about 2323 central standard time, Trans States Airlines flight 4615, an Embraer EMB-145 (registration N856HK), encountered strong gusting crosswinds during its approach to runway 30L at Lambert-St. Louis International Airport (STL), St. Louis, Missouri. The aircraft struck both wingtips on the runway before performing a go-around. The flight crew subsequently conducted an uneventful landing on the second approach. The airplane sustained substantial damage, and there were no injuries to the 33 passengers and crew members onboard.
Flight Background
The flight was a scheduled domestic passenger service under 14 Code of Federal Regulations Part 121, originating from Chicago O'Hare International Airport (ORD) to STL. Prior to departure, the flight crew received dispatch weather indicating visibility of 10 statute miles, overcast clouds at 10,000 feet agl, and wind from 040° at 15 knots gusting to 30 knots. The forecast for arrival time called for visibility greater than 6 statute miles, overcast at 9,000 feet agl, and wind from 020° at 18 knots gusting to 30 knots.
The first officer was the pilot flying, and the captain was the pilot monitoring. After receiving the STL ATIS weather with wind from 030° at 22 knots gusting to 27 knots, the first officer briefed a visual approach to runway 30R. The planned approach speed was 131 knots (121 knots base plus 10 knots for gust factor). The first officer discussed using flaps 22 instead of flaps 45 due to gusty crosswind conditions but ultimately chose flaps 45 for the landing. Air traffic control initially cleared the flight to land on runway 30R about 2318:40, then changed to a visual approach to runway 30L at 2318:52.
Approach and Go-Around
On approach, the airspeed varied ±5 knots between 1,300 and 1,700 feet agl, stabilizing below 1,000 feet agl. The first officer called for gear down and flaps 22. At 2321:36, the first officer remarked about gusty winds and stated, "I don't want to stall". The captain instructed to put the wing down and add rudder on short final. During the flare, with full right aileron and full left rudder inputs, the airplane continued to drift left of the runway centerline. Flight data recorder (FDR) data showed a maximum left bank of 17.41° at 2322:51.2 and a maximum right bank of 15.48° at 2322:54.7, with a momentary weight-on-wheels signal for less than one second. The aural alert system issued "BANK ANGLE" warnings at 2322:52.9 and 2322:55.1. The first officer initiated a go-around, advancing the throttles to maximum thrust. About four seconds later, the captain momentarily retarded the throttles to flight idle for about one second before readvancing them.
Subsequent Landing
After establishing a climb and retracting the landing gear, the first officer transferred control to the captain at 2323:16. The flight remained in a left traffic pattern for a visual approach to runway 30L. The captain elected to land with flaps 22, and the airplane landed safely approximately 15 minutes after the go-around. It taxied to the gate, and passengers deplaned normally.
Personnel Information
The captain, age 59, held an Airline Transport Pilot certificate with type ratings for multiple aircraft including the EMB-145. He had accumulated 30,406 total flight hours, with 12,223 hours in the EMB-145. His FAA first-class medical certificate required corrective lenses.
The first officer, age 24, held an Airline Transport Pilot certificate with type ratings for the CA-212 and EMB-145. He estimated 1,850 total flight hours, including approximately 320 hours in the EMB-145. His medical certificate also required corrective lenses.
Meteorological Conditions
An NTSB Meteorology Study indicated a strong low pressure center in western Tennessee, with expected gusty winds and low-level wind shear. No precipitation was reported at the time. STL ASOS data at 2322 recorded a two-minute average wind from 024° at 19 knots with a five-second maximum gust of 24 knots from 022°. At 2323, the average was from 018° at 18 knots with a peak gust of 23 knots from 035°. At 2324, the average was from 019° at 20 knots with a gust to 28 knots from 024°.
Airport Information
STL has four paved runways. Runway 12R/30L, used for landing, is 11,019 feet long and 200 feet wide, grooved concrete in good condition, with MALSR approach lighting. Runway 6/24 is 7,607 feet long and 150 feet wide, grooved concrete in fair condition.
Aircraft Damage
Post-flight inspection revealed substantial damage to both wingtips and ailerons. The left and right ailerons sustained abrasion to the outboard aft corners, through multiple layers of composite lower skins, affecting trailing edge fasteners. The damage exceeded structural repair manual limits, requiring aileron replacement.
Additional Information
Trans States Airlines policy called for flaps 45 on visual approaches. Minimum landing distances for a dry runway at the estimated landing weight of 37,100 lbs were 4,137 ft for flaps 45 and 5,338 ft for flaps 22, not accounting for wind components. Using steady state wind components, the landing distance for flaps 22 on runway 6 would be reduced by about 400 ft. The crew had performance data for runway 6.
Flight Recorders
The solid-state cockpit voice recorder (CVR) and flight data recorder (FDR) were undamaged and downloaded normally. The CVR recorded communications from 2304:30 to 2331:35. The FDR covered the entire flight.