Denver mayor Wellington Webb fired up the first earthmover late last month as Denver International Airport (DEN) began construction of its sixth runway. The new 12,000- by 200-ft north-south runway was in the airport’s original plans, but was cut to save money. The airport opened in 1995. The $166 million (estimated) new runway, consisting of one million square yards of 17-in.-thick concrete and scheduled for completion late next year, will accommodate simultaneous departures with one of the existing three north-south runways. Two of the parallel runways, with simultaneous ILS approaches permitted, are earmarked for landings at times when winter storms descend on the airport from the north, the prevailing weather pattern.