Saturday, September 21, 2013

Grounded Airplanes: Routines versus Learning

Wall Street Journal has an interesting article about the low-price airline Allegiant Air, which is now making flight cancellations because it urgently needs to check the evacuation slides of its MD-80 aircraft. Why such a problem all of a sudden, when other airlines don't have problems with the same type of aircraft? This is where the story gets interesting.

One of its aircrafts needed an emergency evacuation after a minor incident, and the pilot ordered passengers to slide down the evacuation slides. The evacuation went without problems except for one thing: slides are supposed to inflate automatically when the door opens in an emergency, but only two of the four slides did. The other two had to be inflated manually by flight attendants. (I am assuming that manual inflation means pushing a button, not blowing air into the slide.) Half the slides not opening as they are supposed to is unusual, and the Federal Aviation Agency (FAA) quickly found out that the slides had not been inspected annually, as is required for older slides. The airline promised to fix its slides immediately, leading to the grounding of 34 planes that needed slide inspection or replacement.

Why did Allegiant Air not inspect its slides? Actually it did inspect them, at the three-year interval recommended for newer slides. This was their routine, where routine is a behavior that an organization repeatedly does to address an issue. Common features of routines are that they are easy to do because the organization is experienced with them, and they are not checked because people in the organization believe they are the correct set of actions. But routines can be wrong, like when the calendar for inspecting slides is marked with every third year instead of every year. 

Wrong routines are hard to fix because something needs to tell the organization that there is a problem, and that “something” is often an accident. That almost happened to Allegiance, but fortunately their airplane evacuation was not hurried and did not fail. Instead, they were told of the problem by two other mechanisms that often interrupt harmful routines. One is to document the correct action, as Boeing has done for the MD-80 slides (McDonnell Douglas was the original maker, but Boeing now has the documentation). The other is to communicate the correct action, as the FAA did when it suspected that the incorrect inspection interval had been followed.

Thanks to these actions, Allegiance Airlines evacuation slides for MD-80 planes should soon be in good shape. Of course, there are lots of airplane parts and airlines, so learning about such an incorrect routine is worrying for those who fly frequently.

Carey, S. 2013. Allegiant Air Forced to Ground Some Planes. Wall Street Journal.