Just curious, and know nothing about aviation. But if the plane left the airport 10 minutes earlier and was just 60 miles from where it departed, how could it have been at 28,000 feet, traveling at 600 mph so soon? Do the small jets climb faster than commercial jets?
Wow, just checked and the rate of climb for the Learjet 25 is 6050 ft/min! Could have easily been at 28000 feet in 10 minutes.