iPhone 6 Plus handsets have flown off the shelves since they became available in September, and now the handsets are taking to the skies. United Airlines plans to equip 23,000 flight attendants with iPhone 6 Plus handsets by the second quarter of 2015.

Flight attendants will use the phones for tasks such handling payment transactions and accessing United’s email, website, intranet, ands policies and procedures manuals. 

Future enhancements include replacing the flight attendants' printed safety manual with an electronic version on their iPhones and providing real-time reporting and improved follow-up on aircraft cabin issues and repairs. Additionally, United plans to develop a number of customer-focused tools for the device.

"We are thrilled to make this investment in our flight attendants," said Sam Risoli, United's senior vice president of in-flight services. "iPhone 6 Plus will enable them to deliver an even higher level of flyer-friendly service and will offer our flight attendants simple, one-touch access to valuable work information, enabling them to better serve our customers."

United has been using iPads since 2011 as part of an initiative to have a paperless flying experience, recently upgrading its staff to the iPad Air 2.

Several airlines have become technologically savvy in recent years. British Airways utilizes iPads for its business-class flights from Heathrow airport in London to JFK Airport in New York, giving passengers live updates about their flight.

Delta Airlines partnered with Microsoft to equip 11,000 pilots with Surface 2 tablets, while flight attendants have access to 19,000 Windows Phone handsets for handling payment transactions. Virgin Atlantic U.K. has used Google Glass and various smartwatches to give its staff access to recent flight and passenger information. Virgin Atlantic pilots may soon use Samsung Gear VR headsets as part of their training.

As regulatory agencies such as the Federal Aviation Administration and Aviation Safety Agency update the rules about electronics and Wi-Fi, airlines have also been able to modify their policies and embrace technology as part of their in-flight operations.

Carriers like T-Mobile also offer customers access to in-flight texting and voicemails, while smartphone makers like Apple also equip their devices with the compatible technology.