Simply put, situation awareness is a case of having the three ‘R’s: knowing the right information at the right time and reacting to it appropriately. If we have all the information we need and we apply the proper procedures, getting safely to and from where we need to go becomes easy. Good situation awareness means that pilots know where they are, the desired route to their destination and any obstacles, hazards or rules to be followed along the way. At aerodromes with control towers, what the controllers intend and what the pilots understand must match exactly. If not, good situation awareness cannot occur either for pilots or for ATC. So if good situation awareness is essential for safe operations, how do we gain and maintain it? Another way of saying this is how and why do pilots loose their situation awareness bearings and make critical mistakes as a result? Research has shown that the following factors often result in diminished situational awareness: incomplete or misunderstood communications; lack of planning; work load peaks; distractions; and loss of visual cues. Let’s examine each to see how they may affect situation awareness.By far the most important cause of poor situation awareness induced mistakes is communication problems. Communication difficulties most often result from one or both of the following: use of non-standard phraseology; lack of language proficiency. These communications shortcomings cause a discrepancy between what ATC intends and what the pilots understand or vice versa. Clear, accurate and timely communications are essential in establishing and updating the shared mental picture necessary for good situation awareness.3. What is the most important cause of poor situation awareness?