United Airlines: Too many emergency slides are deploying accidentally

 If the door says "armed," the emergency slide will deploy. 

If the door says "armed," the emergency slide will deploy. 

If you fly United Airlines, look for flight attendants to spend extra time ensuring they have properly opened and closed the aircraft's main door. 

In an internal communication, United warned flight attendants to be careful when "arming" and "disarming" doors. This is fancy talk for something simple. If a door is "armed," the emergency slide will deploy when the door opens. If it is not armed, the slide will not deploy. For passengers to get off the plane in a non-emergency, the door must be disarmed. Going from "armed" to "disarmed" is a simple process - on many planes, a flight attendant switches a lever. 

But humans make mistakes, and United has made some costly errors recently. "Year-to-date we have had 7 Inadvertent Slide Deployments (ISDs) that are attributable to Inflight Services," United told employees. "That is almost twice the number in 2014."

Airlines hate this, because inadvertent slide deployments are expensive, and they require carriers to take planes from service. Most incidents are also avoidable. [The International Air Transport Association, or IATA, has a 30-page guideline detailing how to avoid such errors.]

"It is imperative to follow the steps that have been developed to correctly operate an aircraft door," United told employees. 

Between Oct. 25 and early November, United had three slide deployments, the airline said.  

  • On a Boeing 757, a flight attendant opened the door after it had already been closed prior to push back. He wanted to send some last-minute bags into the baggage hold. But he had already "armed" the door, so the slide deployed.
  • On a A319, a flight attendant on arrival "...pulled the door handle rather than moving the disarming lever," United said.
  • On a Boeing 767-400, a "flight attendant at door 2R was uncomfortable with the door, yet did not ask for help nor did she review door operating procedures. Instead of grabbing the arming lever, she grabbed the door handle."

How big of a problem is this worldwide? See this Tweet from IATA. 

And here's what a mistake looked like recently at another airline.