The Aegis missile cruiser, USS Yorktown, experienced some 
software glitches with its new PC systems running Windows 
NT last year. To be exact, the U.S. Navy had to tow the ship 
back to port. The ship was part of a pilot program to install 
PCs to reduce manpower, maintenance and costs. However 
last September, after some "bad data" was fed into the system, 
the ship was crippled during maneuvers because of massive system 
failures. According to Government Computer News, a database 
overflow caused the ship's propulsion system to fail.

"We are putting equipment in the engine room that we cannot 
maintain and, when it fails, results in a critical failure," said 
Anthony DiGiorgio, a civilian engineer with the Atlantic Fleet 
Technical Support Center in Norfolk. According to DiGiorgio, 
it took two days of pierside maintenance to fix the problem.

In a GCN interview, DiGiorgio was critical of using Windows 
NT on a Navy ship. DiGiorgio, who has worked on Navy ships 
for the past 26 years said, "Using Windows NT, which is 
known to have some failure modes, on a warship is similar 
to hoping that luck will be in our favor."

The military has typically relied on UNIX based system for 
computing, however in March of 1997, both Pacific and Atlantic
fleets selected NT 4.0 as the standard OS for both networks 
and PCs. Ron Redman, deputy technical director of the Fleet
Introduction Division of the Aegis Program Executive Office, 
said there have been numerous software failures associated 
with NT aboard the Yorktown.

"Refining that is an ongoing process," Redman said. "Unix is 
a better system for control of equipment and machinery, 
whereas NT is a better system for the transfer of information 
and data. NT has never been fully refined and there are times 
when we have had shutdowns that resulted from NT. Because 
of politics, some things are being forced on us that without
political pressure we might not do, like Windows NT," Redman 
said. "If it were up to me I probably would not have used 
Windows NT in this particular application. If we used Unix, we 
would have a system that has less of a tendency to go down."

In the end, what you ask caused such a colossal failure on 
the Yorktown? According to a military memo, "the Yorktown 
lost control of its propulsion system because its computers 
were unable to divide by the number zero."