As Convair Three-Niner approaches the runway at Denver International Airport, the airplane also is nearing an imaginary boundary: the dreaded Year 2000 witching hour.
It is moments before midnight, in a crucial test of the Federal Aviation Administration's computer system. The clocks in the airport control center are about to turn from Dec. 31, 1999, to Jan. 1, 2000.
The controller calls out, "Time is one minute prior to entering the new millennium in our test systems. How do you read this transmission?"
The pilot of the Convair replies: "Loud and clear, and if we disappear off the screen, it means we went into the next millennium."
A minute later, after the clocks hit Jan. 1, 2000, and the plane remains a radar blip on approach to Runway 16, the controller calls back, "You are now flying in the Year 2000 in our test system. How do you read this transmission?"
The reply: "It's loud and clear. It went right through the sound barrier very nicely."
So it went late Saturday and early Sunday, as the FAA tested its Y2K computer fixes. Checked were systems that control radar screens and radio transmissions, ground traffic, airport weather reports and the status of landing lights and remote radio beacons.
United Airlines also was on hand, testing its own Y2K fixes. The carrier, the nation's largest, beamed imaginary Year 2000 flight plans from its headquarters in Chicago to Gate B-41 at Denver International.
FAA officials held a dress rehearsal March 27 and conducted lesser drills on three other occasions. But the weekend test was the first open to reporters. It was intended to bolster public confidence in the nation's aviation system as the century crossover approaches.
FAA Administrator Jane Garvey, who stayed up well past 2 a.m. MT (4 a.m. ET) to watch the four-hour test, was pleased with the results.
"Quite honestly, you had to watch the clock to be aware it was changing," Garvey said.
Ray Long, head of the FAA's Y2K program, told agency workers before the test: "Our success will be gauged by the fact that nothing will happen."
Because of the way many older computers are programmed, some software interprets years in a two-digit format, such as "99" for 1999. The concern is that unless software is modified, computers in various industries will malfunction when the calendar changes from "99" to "00," which may be interpreted as 1900 instead of 2000.
That is a special concern in aviation, where computers track airplanes from takeoff to landing. Some travelers have sworn off flying as Dec. 31, 1999, turns to Jan. 1, 2000, fearing planes may collide or fall out of the sky because of computer problems.
On Thursday, the head of Australia's Qantas Airlines said he and his top executives would not fly on New Year's Eve because of the uncertainty.
On July 1, the State Department is expected to relase a list of countries it suggests avoiding around New Year's because of air control computer questions.
Written by Glen Johnson