What happened
On 11 August 2018, an Embraer 175, registration G-FBJK, was prepared for a commercial passenger flight from Dublin Airport to Cardiff Airport. During the turnaround, the flight crew updated their performance calculations because the assigned departure runway had changed from Runway 28 to Runway 10.
While calculating the new takeoff performance using an Electronic Flight Bag (EFB), the co-pilot inadvertently selected a temporary intersection (E7 TMP) which required a flap 4 configuration. Although the commander cross-checked the EFB data, his attention was diverted by a discrepancy in the loading information provided by the dispatcher. Consequently, the crew entered the data into the Flight Management System without noticing the change in flap requirements.
During the takeoff roll on Runway 10, the aircraft was configured with flap 1, despite the calculated speeds being based on flap 4. As the aircraft reached rotation, the co-pilot noticed the aircraft felt sluggish and observed low-speed awareness alerts on the flight instrument system. To maintain safety, the co-pilot reduced the pitch attitude to allow the aircraft to accelerate to a safe speed. The aircraft climbed to 1,000 feet before the flaps were retracted, and the flight continued to Cardiff without further incident. There were no fatalities and no injuries among the 74 passengers or 4 crew members.
The investigation
The AAIB investigation examined the crew's performance calculations and the operator's standard operating procedures (SOPs). The investigation established that the co-pilot had rushed the calculations due to a busy turnaround and failed to notice the specific intersection suffix. The commander's review was compromised by a distraction regarding the load sheet and a lack of sufficient visual contrast between different data fields on the EFB screen. Furthermore, the investigation found that the crew did not perform the required gross error check against the Quick Reference Handbook (QRH) as mandated by their SOPs.
Findings
- The primary cause was an ineffective SOP and non-adherence to existing procedures during the performance calculation cross-check.
- The crew failed to conduct a manual gross error check of the takeoff speeds against the QRH.
- A distraction involving loading documentation prevented the commander from identifying the incorrect flap setting.
- The co-pilot did not specify the use of the temporary intersection during the departure briefing.
- The visual design of the EFB, specifically the similar font size and style for different data types, made it difficult to distinguish critical performance changes.
- Fatigue and a rushed turnaround environment contributed to the errors.