Elon Musk's Starlink internet is being installed across scores of airlines, but not Delta. Bloomberg/Getty Images

Delta Air Lines is one of few carriers opting against installing Starlink internet on its planes.

The airline instead tapped Amazon LEO in March to become its in-flight WiFi provider.

Elon Musk hit out at Delta's choice on X, saying it would be "painful, difficult and expensive."

Elon Musk doesn't seem pleased with Delta Air Lines choosing a rival internet provider to Starlink.

Dozens of airlines around the world have struck deals with Starlink to give passengers free, high-speed WiFi. It connects to a constellation of over 10,000 satellites, helping provide connectivity in remote areas, such as over the ocean.

However, Delta instead tapped Amazon LEO in March to become its in-flight WiFi provider.…