The flight deck of commercial aircraft is sophisticated and searching for the necessary information at the right time is sometimes challenging. This research investigates pilot's visual parameters while interacted with two different designs of crew alerting system by eye tracking technology. There are 24 aviation professionals that participated in this experiment including commercial pilots, private pilots and avionic engineers. Compared with traditional design, the new integrated design applied proximity compatibility principles to assist pilots in searching necessary information to deal with urgent situations. The results demonstrated that the integrated design is superior to traditional design in providing accurate instructions as determined by visual behaviors. However, the integrated design increases pilot's situation awareness by redirecting attention from current task to the most critical task with the cost of a longer total fixation duration time. Pilot's visual parameters demonstrated significant differences while interacting with PFD mainly numeric, ND mostly by symbols and EICAS with presented text messages. Therefore, flight deck design has to adopt a holistic approach as pilot's visual attentions is shifting among all types of different displays to gain situation awareness rather than focus on only one display. The design of integrated EICAS can provide detailed instructions to deal with urgent situations which induced higher cognitive loads as pilot's pupil dilation is significant bigger than interacted with traditional design. By eye tracking technology, it is applicable to design human-centred flight decks to improve safety and human performance in aviation.