Microsoft announced today that Delta Air Lines has handed out Windows Phone handsets to more than 19,000 flight attendants worldwide. The attendants will use the Nokia Lumia 820 with Windows Phone 8 to access an Avanade point of sale (POS) app that was built on the Microsoft Dynamics for Retail mobile POS platform.

"Delta's 19,000 in-flight professionals are there for the safety and comfort of our customers, and equipping them with innovative solutions means they can better meet our customers' needs on board every flight," Delta Senior Vice President Joanne Smith  said. "This is yet another way we're investing in technology to improve the customer experience."

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Delta will use Windows Phone to run credit card transactions in flight for services such as food purchases, seat upgrades, headset rentals, and more. The airline will be able to offer customers electronic receipts and coupons, and do so more quickly and efficiently. The phones will also handle passenger manifests, frequent flyer info, connecting gate updates, and flight attendant scheduling updates, Microsoft says.

According to Delta, the flight attendants will begin using their Windows Phones starting today. But I heard about the deal back in July, and was offered some further news: The usage will eventually reach 22,000 flight attendants. And Delta will be outfitting its pilots with Windows tablets this fall, as well.

Delta services more than 160 million passengers per year and operates almost 5,000 flights a day. It is the world's largest passenger airline by passengers carried and second largest by miles flown.