An Italian economist says his flight was delayed after a fellow passenger saw him working on a differential equation and alerted the cabin crew.
He showed them what he had been writing and the flight took off more than two hours late.
Mr Menzio said the pilot seemed embarrassed and wrote on Facebook the experience was “unbelievable” and made him laugh.
The professor was on board the Philadelphia-Syracuse flight on Thursday on his way to Ontario, where he was due to give a lecture. Before the flight took off, the woman next to him gave a note to a member of the cabin crew.
She initially told them she was feeling ill, but lather voiced her suspicions about Mr Menzio’s writings.
American Airlines, whose partner Air Wisconsin was operating the flight, said the crew followed protocol to take care of a ill passenger and later to investigate her allegations. It was established they were not credible and she was re-booked on a later flight.