"Companies that live by the digital sword, die by the digital sword."

That was the pithy analysis of one observer after Air Canada's recent computer glitch left thousands of angry passengers stranded for hours. It also reduced the airline's ground staff to using a manual check-in process worthy of the airline's founding days back in 1937.

Maybe they should keep another sword handy.

Air Canada is not alone in its digital misery.

A multi-country outage in April left millions of e-mail-loving BlackBerry users banging on their elegant devices, which were reduced to being simple cellphones.

BlackBerry maker Research In Motion (RIM) finally explained that the incident was triggered by "the introduction of a new, non-critical system routine that was designed to provide better optimization of the system's cache."

In other words, a human boo-boo.

Now, the U.K. government is facing howls because it managed to lose important personal data on about half the country's population when some disks went astray in the internal mail service. The data was not encrypted, and could be a treasure trove for identity thieves.

Nobody expects computer programmers or communication network designers or letter carriers to be 100 per cent perfect, but there are precautions that can be taken.

Where the risk is confidentiality, as in the U.K. case, encrypting the data would have helped. Sure, this kind of encoding could be broken by the likes of MI-5, the CIA or the RCMP.

But at least the average Nigel stumbling upon those errant disks couldn't just pop 'em in a computer and start reading personal data.

Network failures like those of Air Canada and RIM are a little more complex, but still foreseeable.

After all, the people who design and build the fuel tanks for airplanes aren't perfect either, which is why most aircraft, even those tiny Cessna 150s, have multiple tanks. A small piece of ice or an insect in the fuel vent could render one side useless - but you have the other one to get you safely on the ground.

So, who could have foreseen Air Canada's woes? In a strange way, I did. And so did an Internet blogger named Alan Gahtan, a Toronto lawyer.

We have both railed against the shoddy design of Air Canada's flagship website, www.aircanada.com, which takes any fun out of booking flights, converts it to sheer drudgery and sometimes ends up throwing its digital hands up in frustration.

In a March, 2006, posting on his blog, titled "AirCanada.com Sucks," Gahtan wrote that "in my view, Air Canada has some systemic problems with the operation of its website."

He goes on to report annoying glitches, and writes: "I've offered to provide one to two hours of my time at no charge to help them troubleshoot the bugs in their system, but there was never any interest on their part."

Maybe Air Canada should have listened to Gahtan, or to me - I once told their help desk how other airline systems allow you to enter an airport code like YYC or YYZ, while Air Canada often gives you an error message if you move too quickly to the next field rather than waiting for their sometimes-sluggish system to recognize the destination.

Of course those help-desk folks were in India, and making the system better wasn't part of their job. In fact, one might argue that the more glitches, the better, for their job security.

Being a lawyer, Gahtan is careful to explain that the aircanada.com website was probably done by a completely separate company from the system that failed Air Canada's passengers on Nov. 16.

But he does stand by his "systemic problems" comment. I would go a bit farther.

A company that routinely (by Gahtan's and my experience) turns away customers trying to make bookings with a pathetic "system error" message is not paying enough attention to good design, debugging and, yes, backup capacity.

To be fair, airline reservation systems are big, complex programs. Earlier this year, Calgary-based WestJet Airlines took a whopping $31.9-million (pre-tax) write-off for its failed computer reservations system project. Heads rolled in that debacle.

Air Canada spokeswoman Angela Mah said that company's outage was being investigated, but that no details were yet available.

She did note that the problem - which affected all check-in functions via the Internet, airport kiosks and agent computers - started at 4:30 a.m. EST and was resolved by 11 a.m. EST.

Mah also noted that an initial diagnosis indicated a programming issue affected connectivity and communications between the central reservations system, the Internet and the airport."

Big boo-boo.

Of course we'd all rather an airline keep its planes in the air flawlessly than its ground computers running, but that shouldn't really be the choice we have to make, according to Zak Karbalai.

Karbalai is the director for business continuity and security at Calgary-based Care Factor Computer Services Inc., a company that offers services ranging from an assessment of how your IT infrastructure would survive a disaster to backup IT facilities located at an undisclosed location.

While he doesn't know the specifics of the Air Canada glitch, Karbalai says that he's seen companies spend serious money on disaster preparedness, but still miss the biggest point - the human factor.

"Even if Air Canada and RIM, for example, have the business-continuity plans and high-availability sites, they might be vulnerable if they haven't tested it and practised regularly," he says. "Then if they are hit by something like this, they don't know what to do even if they have spent the money and they've got everything in place."

For people who enjoy the lighter side of computer crashes, check out the Risks Digest, a collection of bug reports moderated by California-based computer guru Peter Neumann.

His latest missive involves an asteroid that was about to collide with Earth.

Quick, alert NASA! Call Norad!

Oh wait a minute. Cooler heads determined that it was the European Space Agency's Rosetta spacecraft, making a regularly scheduled trip past the Earth.

Whew! Another disaster averted.

Web Watch: www.gahtan.com (Tom Keenan is a professor at the University of Calgary and an expert on technology and its social implications. He can be reached at keenan@businessedge.ca)