The nightmare continues for Boeing's 787 Dreamliner, and now two Arizona companies have found themselves talking to federal investigators about the problems that have grounded the 787.
At issue are the plane's lithium-ion batteries.
Federal investigators are now looking into the factories where the new plane's battery and battery chargers were made.
Among the companies being asked to take part in that investigation -- Securaplane in Tucson and UTC Aerospace here in Phoenix.
Neither company is talking specifics about the investigation, only to say they are cooperating with investigators.
As for the battery itself, Boeing is the first to use lithium-ion batteries on an airliner.
It's the same type of battery technology used on new smartphones, but obviously on a much larger scale.
"These lithium-ion batteries on an aircraft are being subjected to much greater temperature extremes, much greater pressure extremes, because those airplanes are going up to 40,000 feet and much higher loads of electricity. So certainly when you see your iPhone, magnify that a thousand times and all of a sudden you got a battery like that on one of these airplanes. But I'm sure they would've thought of all of that. Sometimes things are just missed," says Timothy Mccullough, aviation legal expert with Gordon & Rees.
The two Arizona companies involved in the investigation don't make the battery, but instead components that help power the battery.