As anyone who’s ever looked at a plane surely knows, not all aircraft are the same. There are some that are designed for short hops or longer trips, and others that are made for long haul flights over water. American Airlines has admitted it got its aircraft a bit mixed up last month, sending a plane on a flight from Los Angeles to Hawaii that wasn’t cleared to make that kind of trip.

Aviation blogger Brian Sumers was the first to report the mistake on his blog, writing that an airline spokesman acknowledged the mix-up and that the carrier is now revising its internal procedures as a result of the mistake.

The confusion was between two kinds of Airbus A321 planes — there’s the A321H, which has the proper certification to fly to Hawaii, and the A321S, which does not. That certification is called ETOPS, and requires an aircraft to carry more safety equipment than other planes. The special systems on an ETOPS-certified plane allows the aircraft to fly on one engine for as long as three hours, which is enough time to reach an alternate airport if it needed to.

On Aug. 31, American Flight 31 from L.A. to Honolulu used an A321S, a spokesman told Sumers. Though the planes are basically the same and passengers likely weren’t in any danger — both aircraft are equipped with emergency life rafts required for a water evacuation — it’s big breach of federal guidelines.

An American worker on the ground realized the switcheroo while the plane was already in the air, and American decided to let it continue on to its destination, the spokesman said. The return flight was then canceled and the plane was ferried back across the Pacific Ocean.

“When we noticed it, we immediately undertook an internal investigation, and we alerted the FAA,” the spokesman said. “We are checking our internal procedures, everything that led up to the departure. We are going to figure out what we can do better. We have gone back and made some changes to software systems.”

The Federal Aviation Administration is reportedly looking into the matter as well.

How American Airlines flew the wrong A321 to Hawaii [BrianSumers.com]

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