Portuguese operator HiFly has tightened its go-around training after a microburst encounter on final approach to Darwin, Australia, resulted in an Airbus A340-300 hard landing and the jet being ferried for repair.
The aircraft (CS-TQM) contacted runway 29 with an impact of 2.71g after the A340-300 was subjected to a headwind that quickly transformed into a tailwind.
Chartered for the Australian Defence Force, the jet had been transporting 116 passengers and a crew of eight from Sydney when the crew saw heavy rainfall close to the runway threshold.
At about 180ft (55m), the headwind was 14kt (26km/h), the Australian Transport Safety Bureau states, although air traffic control had advised of a 5kt tailwind at the threshold.
The crew had briefed for a missed approach if the weather conditions deteriorated, the bureau adds, and had expressed concern to air traffic control about the possibility of windshear - asking whether windsocks at the airport were showing differing wind directions.
Rain during the final stage of the night approach was heavy and the crew noticed an increased sink rate, and set power to maximum continuous thrust to stabilise the descent rate. At a height of 25ft, having reduced the rate of descent to 300ft/min (1.5m/s), the crew set the thrust to idle. But flight-data recordings analysed by Airbus show that, just before touchdown, the wind component changed from a 9kt headwind to a 6kt tailwind in the space of 2.5s, and that there was a downdraft component of 7kt.
In the last moments before touchdown, the pilot made two consecutive nose-down inputs, then two full-back inputs on the side-stick control. The aircraft nevertheless landed with a descent rate of 783ft/min, with the tailwind having increased to 18kt. Inspections at Darwin after the 28 February incident revealed a cracked retainer on an outboard engine attachment point - although a link with the hard landing could not be confirmed - while several main landing-gear components were replaced after engineers considered they might have exceeded design limits.
HiFly has worked to "increase the go-around mindset" among pilots, says the bureau, permitting first officers to initiate a go-around without needing to obtain the captain's consent and amending simulator sessions to feature go-arounds from 50ft and immediately after touchdown.