A British Airways 787-8 (G-ZBJB) crashed at Heathrow on June 18th while preparing for a cargo flight to Frankfurt. According to the UK’s Air Accidents Investigation Branch (AAIB), the event was caused by human error.
The incident occurred while crews were completing a “Dispatch Deviation Guide” (DDG) process, which allows an aircraft to operate under defined conditions with specific instruments or functions inoperable for a period of time until recertification can be accomplished.
The cockpit landing gear selection lever had to be cycled while hydraulic power was provided to the aircraft. According to AAIB, “the process needed pins to be put in the nose and main landing gear down locks to prevent the landing gear from retracting.”
The NLG [nose landing gear] down lock pin, on the other hand, was put in the NLG down lock apex pin bore, which was near to the correct location for the downlock pin. The NLG retracted when the landing gear selector was cycled.”
The mechanic in charge of the 787’s landing gear was not tall enough to reach a pin required to lock the landing gear. As a result, another taller mechanic stepped in. However, the second mechanic inserted the pin into the incorrect recess. Because of the miscalculation, the landing gear abruptly retracted into a flying position. And the plane crashed when an engineer tested the hydraulics.