An Ivy League professor aboard an American Airlines flight was questioned after a passenger mistook a math equation for Arabic and possible Islamic code for a terrorist attack.

Guido Menzio, an economics professor at the University of Pennsylvania, was working on a differential math equation as the Syracuse-bound plane was preparing to take off from Philadelphia.

The 41-minute flight was delayed by two hours as the olive-skinned, curly, dark-haired native Italian was questioned.

After it was found he was only doing math, the flight took off minus the complaining passenger, who boarded a later flight for Syracuse.

Menzio has been a member of Penn's faculty since 2005. Last year, he was awarded the prestigious Carlo Alberto Medal as the best Italian economist under 40.