Flight attendants for a United Express regional carrier voted 99 percent to authorize a strike, their union announced this week.

But, they won't all probably walk off the job at once. That would be too easy.  

Instead, if they strike, they say they'll implement a system called CHAOS (the union trademarked the name), which stands for "Creating Havoc Around Our Systems."

"With CHAOS, a strike could affect the entire system or a single flight. The union decides when, where and how to strike without notice to management or passengers," the union said in a press statement. (I added the emphasis because--really, "without notice to passengers?")

With that, here's a brief history on how CHAOS works, along with what has to happen before it happens, and why United Airlines should still be worried.

CHAOS theory

As the union statement notes, the whole point behind CHAOS is that the flight attendants can get the same reaction from the threat of a strike, or a strike that turns on and off at their whim, that they'd get from a real strike.

The big benefit for flight attendants is that they wouldn't have to go without a paycheck, because they'd only strike sporadically.

An airline can't really just shut down during a CHAOS strike; it would be leaving chunks of revenue on the table. But at the same time, demand would plummet. I mean, would you fly on an airline where the employees are threatening to strand you with zero notice?

I read up on the history of CHAOS strikes, and the first time flight attendants used this strategy, against Alaska Airlines in 1993, they did things like announce a strike on all flights out of San Francisco--only to rescind it 20 minutes later.

It wreaked havoc on the airline's schedule, according to the book Labor Relations in the Aviation and Aerospace Industries, with flights canceled and then causing ripple cancelations throughout the system. But the flight attendants barely saw a dip in their pay.

Minimum impact on the flight attendants; maximum chaos for the airline. Pure genius, or pure evil. You decide.

Air Wisconsin and United Airlines

We should emphasize two points.

First, a couple of things have to happen before the flight attendants could actually implement this strategy. They've been negotiating for more than two years without a new contract, and they'd need the National Mediation Board to declare a deadlock.

Then, they have to go through a 30-day cooling off period. So if they could do it quickly, that would put them in position to start right before the Christmas holidays. Wonderful.

And second, these flight attendants work for a regional carrier, Air Wisconsin, that flies CRJ-200 regional jets under contract with United Airlines as United Express. It's not the same thing as working directly for United Airlines itself. The employees certainly know that.

But, do you remember a 18 months ago, when when a passenger named David Dao was dragged and bloodied off a United Airlines airplane?

Trick question: he was actually on a Republic Airlines jet operating as United Express, much like these Air Wisconsin planes do.

But that barely mattered. It was United Airlines that took the brand hit, and it was that incident that ultimately led to President Trump signing a law this year banning passengers from being removed from planes like that.

So if I were "big United," I'd be concerned about this. I wouldn't want to risk what could happen if passengers on one of my regional carriers started being stranded because of a CHAOS strike.

By the way, I asked both United Airlines and Air Wisconsin for comment. United declined, and Air Wisconsin didn't respond. If they change their minds, I'll include replies.