Google Maps is flying – literally.  The company has issued planes to fly over cities to take pictures as part of its plan to create a digital map of the world.

Google declined to name the cities, but it showed a demonstration of a 3D map of San Francisco in which someone can navigate around an aerial view of the city, Reuters said.

"We're trying to create the illusion that you're flying over the city, almost as if you were in your own personal helicopter," said Peter Birch, a product manager for Google Earth.

By the end of the year, Google said it expects to have 3D map coverage for metropolitan areas with a combined population of 300 million people.  The first 3D cityscape will be available in a few weeks.

The planes are owned and operated by contractors flying exclusively for Google, the company's head of engineering for the project said.

Google has used airplanes to collect aerial photos in the past, but the latest interest marks the first time the company will deploy the planes in a systematic manner to build a standard feature in one of its products.

The company also announced a version of Google Maps for Android smartphones that allows users to access certain maps without an Internet connection.

Google Maps to be ousted from iPhone

Apple is planning to oust Google Maps as the default maps app from the iPhone and iPad in order to make way for a new app that runs on Apple's own technology.

A preview of the new software could come as early as next week, the Wall Street Journal said. 

Apple has been planning to ditch Google Maps for years, according to current and former employees.  The plan accelerated as smartphones powered by Google's Android software overtook the iPhone in shipments.