Flying schedule-matching descents ta explore flight crews' perceptions oüi their load and task flexibility

Slow to fast speed schemes were the hardest condition - 220kts at 25 000' was the hardest speed reduction to achieve - Large variations from the profile increased crew workload. Most crews tried hard to achieve the clearances - Despite this, a wide variation in times to fly the routes (>;180 seconds). Training assumptions were unverified - Improved knowledge of the FMC would benefit crews in a future CMS environment. 20% variation in speeds is barely acceptable - Some big changes in speed are less acceptable than others - Poor conditions - weather, fatigue, equipment issues - would make 20% variations unacceptable - Occasionally a large change in speed is possible.