DUBLIN, Ireland: Michael O'Leary and Elon Musk, the world's richest man, have been engaging in a war of words over the abilities of Starlink, which offers high-grade internet service and is owned by Musk.

After Musk described O'Leary as "misinformed" over the capabilities of Starlink, the latter called Musk an "idiot" and urged people to pay "no attention whatsoever" to the world's richest man.

After Ryanair announced it would not be installing the technology onboard, citing the extra fuel it would require, Musk said he doubted the company could "measure the difference in fuel use accurately, especially for a one-hour flight, where the incremental drag is basically zero during the ascent phase due to high angle of attack."

On The Hard Shoulder on Newstalk, O'Leary said that "what Elon Musk knows about flights and drag would be zero."

He said Boeing had confirmed that an aerial antenna would need to be installed on top of the aircraft, increasing fuel consumption by about two percent. He explained that since the airline's annual fuel bill is around US$5 billion, the added cost would be about $200 million to $250 million a year.

That would work out to roughly an extra dollar per passenger, and he said the airline could not afford that expense. He added that while passengers would use free internet if it were available, they would not be willing to pay even one euro to access it.

O'Leary also said he would ignore anything else Musk posted on the social media platform X, which he criticized, and noted that Musk had supported Donald Trump's election.

"I would pay no attention whatsoever to Elon Musk. He's an idiot - very wealthy, but he's still an idiot," O'Leary said.