Rational Survivability

I’m sitting on the tarmac at Logan in an A320.  I’ve been sitting here for almost an hour behind a fleet of other united planes.
According to the pilot, United has experienced a system-wide computer outage that affects the navigational systems of all planes.
We can’t take off because the plane doesn’t know where to go…and neither does the pilot.
So much for triple redundancy!

Hoff

** Update: I guess he wasn’t kidding!  That’s realtime blogging for you folks! 

Here’s a link from Bloomberg as an update regarding the failure:

United Air Says Computer Failure Blocked All Takeoffs (Update5)

By Susanna Ray

      June 20 (Bloomberg) — UAL Corp.’s United Airlines, the
world’s second-biggest carrier, stopped all takeoffs around the
globe for more than two hours today after the failure of the
computer that controls flight operations.         

The outage lasted from 9 to 11 a.m. New York time, delaying
about 268 flights and forcing 24 cancellations, the Chicago-
based airline said. United said it was investigating and hoped
to resume normal operations by tomorrow.         

United relies on the computer that broke down today for
everything needed to dispatch flights, including managing crew
scheduling and measuring planes’ weight and balance, spokeswoman
Robin Urbanski said. Federal law requires weight-and-balance
assessments for passenger flights before takeoff.         

A worldwide grounding from a computer fault is “very
unusual,” said Darryl Jenkins, an independent aviation
consultant in Marshall, Virginia. “Somewhere there was a
massive failure.”         

…

Delays, Cancellations         

Delays at Chicago’s O’Hare International Airport, the
world’s second-busiest and United’s main hub, averaged one to
two hours, said Wendy Abrams, a spokeswoman for the Chicago
Airport System. Officials opened gates at the international
terminal to unload stranded United passengers.         

United has a backup for its Unimatic system, “and we’re
investigating why that didn’t work,” Urbanski said. Planes
airborne during the breakdown were allowed to keep flying, she
said.         

Preflight weight-and-balance checks are an important safety
step. Improper loading reduces speed, efficiency, climbing rates
and maneuverability, according to a Federal Aviation
Administration handbook. Those changes, combined with abnormal
stresses on an aircraft, can lead to crashes.         

The Unimatic system “handles all the operational parts of
the airline,” said Rick Maloney, a former United vice president
for flight operations who is now dean of the aviation college at
Western Michigan University in Kalamazoo.         

`Well Protected’         

“That system is so well protected,” Maloney said in an
interview. “I’m really pretty surprised.”         

Companywide shutdowns because of computer glitches are
infrequent, said Robert Mann of R.W. Mann & Co., a Port
Washington, New York-based consultant. “But every airline has
been bitten at one time or another by system failures of this
sort, whether they be dispatch, departure control, passenger
service, kiosks, communications, baggage or some other.”         

Today’s delays will add to the industry’s tardiness so far
this year.         

U.S. airlines managed only 72.5 percent of flights on time
this year through April, the worst rate since the federal
government began keeping track in the current format in 1995,
according to the U.S. Bureau of Transportation Statistics.         

Consultants including Jenkins said today’s computer
meltdown shouldn’t damage United’s long-term reputation. “These
are things that you recover from,” he said.