A data input error contributed to the flight crew of an Airbus A320 turning left shortly after take-off contrary to the cleared standard instrument departure, and at a height of about 223 feet above the ground, below the minimum height for turns specified by the operator, an ATSB investigation has found.
The Indonesia AirAsia A320, with six crew and 145 passengers on board, was operating a scheduled passenger service from Perth to Denpasar, Bali on 24 November 2017.
The subsequent ATSB investigation found that the first officer, who was the pilot flying, had assumed runway 03 would be in use, and not the reciprocal runway 21. On the previous sector into Perth, the aircraft had landed on runway 03, and the first officer believed that they would be using the same runway for take-off, as he had done on previous occasions.
Consequently, the first officer programmed runway 03 for take-off into the aircraft’s flight management guidance system (FMGS) before listening to the automatic terminal information service (ATIS) broadcast for Perth Airport, which detailed that runway 21 was in use.
Although the first officer noted runway 21 on his paper flight plan, he did not notice this differed from what he had programmed into the FMGS, and he briefed the captain for a runway 03 take-off.
Further, the captain, who was pilot monitoring, did not independently verify the runway in-use during his pre-departure checks, and likely relied on verbal information from the first officer, the investigation report details.
Despite a number of cues available, including several air traffic control (ATC) instructions for using runway 21 and airport signage, and later reporting to the ATSB feelings of unease about the flight preparations, the flight crew did not detect the incorrect programming of the FMGS.
Due to that incorrect programming, shortly after take-off from runway 21, the flight director on the aircraft’s primary flight displays commanded a left turn. When at about 223 feet above ground level, the first officer initiated the turn and then engaged the autopilot, which started the left turn to navigate the aircraft towards the first programmed waypoint, which was in-line with the opposite runway direction and behind the aircraft.
ATC quickly noticed the diversion from the cleared track and corrected the crew’s heading.
Later in the climb, once the crew had detected that the FMGS had been incorrectly programmed, the captain reprogrammed the correct flight plan in the FMGS, rather than selecting the heading assigned by ATC. This resulted in the aircraft turning through the ATC-assigned heading, requiring further instructions from ATC, before the flight continued on to Denpasar without further incident.
“Deviating from standard procedures, even slightly, can render them ineffective and result in errors,” said ATSB Director Transport Safety Dr Stuart Godley.
“The incident highlights the significance of stopping and re-evaluating the situation while on the ground when there is a feeling of uncertainty about the flight, even if it results in undesirable delays. This provides an opportunity to detect errors before they affect operations, as, once airborne, workload and time limitations become even more critical due to the rapidly changing situation.”
Since the incident, Indonesia AirAsia have incorporated a ‘change of departure runway’ scenario in their line operations flight training. The airline also has plans to launch a cross-departmental initiative to increase the awareness and skill sets of pilots, especially in the area of threat and error management.
Data input errors are one of the ATSB’s SafetyWatch priorities.
Read the report: Data entry error and operational non-compliance involving Airbus A320, PK-AZE, Perth Airport, Western Australia, on 24 November 2017