Governments and industries are spending billions of dollars on renovating and testing computer networks to assure that they will continue to operate in the year 2000. The U.S. government alone is spending $20 for every person in the nation to fix this dreaded bug in the system. The FAA will have spent an estimated $185.6 million once the last year 2000 bug has been rooted out of its computers, according to FAA spokesman Paul Takemoto.
Besides the year 2000 bug, there are other end of century problems as they are called by computer programmers. Some of these computer glitches will also affect aviation. There is the GPS End-of-Week Rollover, the Four-Century Leap Day bug, the Day-of-Week bug, and the Magnetic Drift Error. On top of it all, even if all the computers are fixed, there is the End-to-End Data Transmission problem to be solved. All of these potential problems are hidden in millions of computers around the globe. Some of those computers are critical to aviation safety. Some of them are even airborne in the airplanes we fly.
The Y2K bug
The year 2000 bug, or Y2K as it has been named in engineering shorthand, occurs when the computer coding for the year is written as a two-digit number. The computer program in this case has no way to determine which century it is, and it calculates all dates as if it were still in the 1900s. January 1, 2000, will be calculated as January 1, 1900, 100 years off.
Air traffic control computers have subroutines where, in almost every case, starting dates are programmed into them. If the computers believe that the date is 1900, they may conceivably wait 70, 80, 90, or even 100 years before reestablishing a particular function of a radar display.
The solution to the problem is relatively simple. Find the code and change it from a two-digit year code to a four-digit year code, or teach the computer to recognize dates from the first half of the century as dates in the twenty-first century instead of the twentieth. Some computers don't need to know what century it is, and the operators may be tempted to leave them alone and allow the 1900s to start again.
The problem is that these date codes are hidden in millions of lines of old computer languages that have long been forgotten. Newer computers and programs are aware of the date and 2000 is not an issue. Generally it is only a problem with computer software created before 1980 or thereabouts.
Four-century leap days
Every fourth year is a leap year, but the Gregorian calendar omits the leap day every 100 years, in years ending in zero-zero. However, for even more accuracy, there is an exception to the omission: years divisible by 400 are leap years after all. This means that 1900 was not a leap year, but 2000 will be. If a computer thinks that the year is 1900, it will move the calendar to March 1 when in fact it is February 29. From that point on, it will be one day off.
The day-of-week bug
January 1, 1900, was a Monday; January 1, 2000, will be a Saturday. If a computer automatically determines the day of the week in its calculation, it may become two days off. One computer in the air traffic control system stores flight plans — some of them on file weeks, or even months, in advance for recurring airline flights.
Magnetic drift error
The difference in magnetic variation around the globe has shifted plus or minus two degrees in the last 100 years. Navigation systems and moving-map software with the Y2K bug may calculate current magnetic variation with a slight error in temperate and tropic regions and larger errors in polar regions. True course will still be accurate, and the units will still be usable but may require a placard.
End-of-week rollover
End-of-Week Rollover is a problem that is not associated with 2000; it is only coincidental that it takes place near the end of the century. The counters on the Navstar/GPS satellites used in GPS navigation can count only 1,024 weeks, from zero to 1,023. That is 19.69 years. At the end of 1,024 weeks, the end-of-week counters "roll over" and begin again at zero. This value is sent to the GPS receivers, which may fall back in time 20 years, looking for the satellites in the positions they should have occupied two decades ago.
The next rollover will take place on August 21, 1999, at 23:59:47 UTC (thirteen "leap seconds" have been added by the sacred timekeepers since the system was first created). Some GPSs will calculate the rollover moment as 13 seconds before January 6, 1980.
End-to-end data transmission
The deadliest bug to computer networks is end-to-end data transmission. Although year 2000 bugs can be eradicated from a system, there are different solutions, and the solutions are not always compatible. For example, a computer that retains a two-digit year code may transmit an erroneous date to a computer seeking a four-digit year code. This may cause the failure of data transmissions that carry date information — almost every stream of data transmission.
Lacking a standard for date encoding, computers have to be taught to interpret the various different types of dates or be restricted to a network where a standard has been reached.
The GAO plan
The U.S. Government Accounting Office (GAO) has been assigned the responsibility for getting the government moving on the Y2K bug. It has put together a five-phase schedule: awareness, assessment, renovation, validation, and implementation.
The awareness phase is the initial planning of logistics and schedules. During the assessment phase the programmers scan all of the code and find the Y2K bugs, and they evaluate the risk to the entire system. Contingency plans are also developed during this phase.
In the renovation phase the code is rewritten and corrected, and systems that need replacement are indeed replaced. The validation phase puts each computer through rigorous date testing by changing clocks. The validation phase must include every conceivable arrangement of end-to-end data transmission.
In the last phase, implementation, the systems are brought online and the certification is completed for "Year 2000 Compliance."
GAO's schedule is a tight one: The awareness phase had to be completed by March 2, 1998; the assessment phase had to be completed by March 31; the renovation phase had a deadline of September 30; the verification phase deadline is March 31, 1999; and the final implementation compliance deadline is June 30.
Where does this put ATC?
Takemoto said that by September 30 the FAA had completed 99 percent of the renovation phase, including all air traffic control systems. Two computers purposefully left off the schedule are the only two computers not yet renovated for Y2K, and these are in the area of pilot records in Oklahoma City. Takemoto said that these systems will be renovated by the end of the year and will be on line by 2000.
This may come as a surprise to most pilots who have been keeping up with the FAA's progress. Only two months earlier, it was reported that the FAA had only 60 percent of the computer code renovated. However, the method that the FAA uses to perform and document renovation completion uses individual teams at each facility so that the whole of the work is being performed concurrently. It was no surprise that most of the work was completed in the last month of the assigned time.
FAA Administrator Jane Garvey has taken the Y2K issue very seriously. She put Ray Long, a longtime FAA computer expert, in charge of the agency's Y2K Program. He stated, "As an indication of our confidence that the FAA will get the job done, Administrator Jane Garvey and I will be boarding a plane on the East Coast shortly before midnight on December 31, 1999, and fly west through all four Continental time zones."
The verification process still looms ahead of the FAA. Although the agency has six months to finish its testing, one source inside the FAA familiar with the Y2K program, and who spoke on condition of anonymity, said that most of that time will be in planning and scheduling the logistics of the verifications. On the current schedule only two months are available for the complete testing program, he said.
From the documentation reviewed, the FAA seems to have made a big comeback and is on schedule for a June 1999 completion date.
The FAA's contingency planning, however, may leave something to be desired. Bill Blackmer, National Air Traffic Controllers Association (NATCA) director for safety and technology and a controller at the Washington Air Route Traffic Control Center, said that the FAA has directed each individual facility to work out its own contingency plan; and for data transmission contingency plans between facilities, there is no program at all.
Long said, "Our folks [NATCA members] want some refresher training on nonradar procedures, and the FAA just said that we are already properly trained in it. I haven't had that kind of training since I was back in [the Air Traffic Academy in] Oklahoma City in 1987."
Taking a fix on GPS
Two big problems exist on the GPS front, in the ground control system and in GPS receivers.
The Navstar/GPS satellites all operate independently of calendar dates, but unfortunately the ground control system that keeps the system running has been found by the government to be the one system most vulnerable to Y2K. It is riddled with bad date codes, according to Emmett Paige, Jr., assistant secretary of defense for command, control, communications, and intelligence, who testified in early 1997 before the House Government Reform and Oversight subcommittee on government management, information, and technology. Because this system is paramount to the nation's defense, it has been given top priority in the national Y2K plan, and no resource has been denied. Almost every expert familiar with the progress of Y2K compliance on this program agrees that it will be completed in time.
Other than military GPS receivers, however, the government has no way to assure that GPS receivers are Y2K compliant. Some may not even handle the End-of-Week Rollover.
Consumers have voiced concern that the manufacturers may have been quiet on the issue, but the truth is, none of the manufacturers knew which systems were compliant, and they have judiciously waited until they could provide documented answers upon the conclusion of all testing.
Many of the companies are only now publishing the results of their tests. Almost every aviation GPS receiver, whether or not it is certified for IFR, will be Y2K and End-of-Week Rollover compliant. Early marine GPSs seem to be the ones most prone to End-of-Week Rollover failure, and pilots using such units should be aware of the problem.
On August 21, 1999, some of the aviation GPS units may become lost momentarily until they can reacquire the satellites. The first time the system is used after the rollover date, users may notice the GPS taking an extraordinary amount of time to locate itself, as it has misplaced the satellites, so to speak, and is reacquiring their new positions in the current week count, according to Bill Stone, product support manager at Garmin Corporation.
Weather and other systems
Most navigation facilities are not affected by computers. VORs, ILSs, NDBs, and lighted beacons should all operate normally. The software that schedules maintenance was found to have some Y2K problems, and some schedules were inadvertently dropped before the problem was detected, according to a report distributed to air traffic control facilities by the Professional Airways Systems Specialists (PASS), the union of FAA technicians. However, other than requiring some backup bookkeeping, it does not generally affect most navigation systems.
Almost every National Weather Service (NWS) weather product is reported by date of month and four-digit time. It does not report which month or which year, so it rolls over every 31 days, at most. Automated weather reporting stations and the GOES satellites are also Y2K compliant. National Weather Service Y2K end-to-end test manager Howard Diamond said that his agency is one of the first agencies to complete its Y2K renovation phase and is almost finished with its verification phase. It began end-to-end data testing in October.
Diamond said, "METAR [conversion] was a bigger problem in 1996; all programs and decoders had to be programmed for it. METAR was a much larger project than Y2K."
Back to the E6B
Myriad avionics are increasingly dependent on computer chips, especially flight management systems and inertial navigation systems. Some computer chips have date-code programs hardwired into them and can experience Y2K failure. The FAA is requiring all manufacturers of certified avionics to document Y2K compliance. Contact manufacturers to find out how an individual system stands up. Pilots will be wise to do a thorough preflight check of all chip-driven electronics on the first flights after December 31, 1999.
The word from Jeppesen
Jeppesen Sanderson creates its charts by hand, on graphics software. The dates on charts will be current and charts will be completely usable. Jeppesen has not yet completed all testing and chose not to make an official statement concerning its Y2K preparedness, other than to say that it expects to be fully compliant by 2000. Hank Fore, director of information technology, speaking unofficially, said that he expects his team to have the most difficult work bringing Jeppesen's subscription fulfillment software into compliance, a problem now facing all magazine publishers and other subscription products. Jeppesen is ahead of the rest of Times Mirror, its parent organization, in working out the Y2K bug, Fore said, and he strongly believes that there will be no interruption in subscriptions. Database products are also being reviewed for Y2K compliance, in conjunction with the manufacturers of products using the databases.
Airports may be hardest hit
Everything appears rosy for aviation,it would seem. The FAA is on track, weather briefings will still be easy and simple, and the GPS issue seems to be a nonissue. However, Garvey reported to a congressional hearing that the FAA surveyed 81 of the country's airports and found fully one-third of them had no Y2K plan at all. They were doing nothing to prepare for the problem. Another 24 airports were clearly more than three months behind in fixing the problem. That is a dramatic ratio. Although most general aviation pilots may suffer no more than bad dates on their tiedown receipts, it should be remembered that most instrument landing and runway light systems are owned and operated by airport authorities. These systems usually do not rely on computers to work, but if the local power or communications grids go down as a result of a Y2K problem, it could cause the airport to close.
What does it mean to GA?
The fireworks and flying champagne corks brought on by New Year's celebrations may pose more of a flight hazard than Y2K. It will be wise in the first weeks of 2000 to make sure that the destination airport will be open. Other than that, there will be little impact of Y2K and End-of-Week Rollover on general aviation. According to Blackmer, even if the ATC system does fail, controlling air traffic at lightplane speeds is simple using paper and pencil. The real problems would be the delays into larger airports or through Class B airspace.
There is, however, a cost attached to all this good news. As noted earlier, the FAA intends to spend $185.6 million on its Y2K program. In 1998, the FAA spent $18 million of government Y2K funds and sapped $37.7 million from other FAA programs. The FAA also spent a supplemental fund of $14 million. The FAA requested $69 million of Y2K money from Congress in 1999, and it will ask for the rest in 2000, said Takemoto. None of this money is coming from the Airport Improvement Program or the Aviation Trust Fund.
However, Garvey recently asked Congress to allow airports to spend $100 million of the AIP fund on Y2K programs, under the auspices of airport improvements, a supplement that may be necessary to assure that the airports remain open on January 1, 2000.
For more information, visit the FAA Y2K Program Web site ; Navstar/GPS Joint Program Office site ; and the National Weather Service site . — Ed.
What GPS manufacturers are saying
Bill Stone, product support manager for Garmin International, stated that all of its GPS products are fully compliant into the next century. "That is one of the advantages of being a new company," he said.
Garmin International, 1200 East 151st Street, Olathe, Kansas 66062; 913/397-8200; www.garmin.com
Northstar Technologies has issued a letter stating, "All GPS systems manufactured or sold by Northstar Technologies as of September 1993 are fully Year 2000 compliant. In addition, all GPS systems manufactured or sold prior to September 1993 can be upgraded to full Y2K compliance via a no-charge software upgrade."
Northstar Technologies, 30 Sudbury Road, Acton, Massachusetts 01720; 800/897-7251; www.northstarcmc.com
According to the Trimble Navigation Ltd. Web site, all aviation products will be compliant, although most will need a "Week Number Roll Over Reset" period. The TANS (Trimble Air Navigation System) Vector navigation system will need to be cleared on August 22, 1999.
Trimble Navigation Ltd., Corporate Offices, 645 North Mary Avenue, Sunnyvale, California 94086; 408/481-8000; www.trimble.com
II Morrow's line of aviation GPSs are all End-of-Week compliant, but the company had not yet completed Year 2000 testing at press time. The testing should be completed and posted on the company's Web site in the very near future.
II Morrow Inc., 2345 Turner Road South East, Salem, Oregon 97302; 503/391-3411; www.iimorrow.com
AlliedSignal (Bendix/King products) has one of the best reports of its products at its Web site. Its systems will be fully compliant, with a few curious exceptions. The KLX 135 and 135A GPSs and the KLN 90 and 90A products flag February 1, 2000, as January 32. This problem occurs every leap year, so it is not really a Y2K problem but an inherent leap year problem. The KLX 135 and 135A GPS/Comm transceivers will be inoperative for the entire day on February 1. The KLN 90 and 90A GPS RNAV systems will show the date as January 32 but will function normally, and the date will be corrected on February 2. The KLN 90B is not affected.
The AlliedSignal KNC 660 FMS will need a special database for a month after December 30. The AlliedSignal KLN 89 and KLN 89B GPS RNAV Systems will display the wrong day on any February 29 until satellites are acquired.
AlliedSignal Aerospace, One Technology Center, 23500 West 105th Street, Olathe, Kansas 66061; 913/782-0600; www.alliedsignal.com
Magellan had not completed any testing at the time of this report, but Ken Kochi, sales and marketing manager for aviation products, said that the results of testing will be posted on its Web site.
Magellan Systems Corp., 960 Overland Court, San Dimas, California 91773; 800/669-4477; www.magellangps.com/frames/frame5.htm
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