The plane then departed from London's Stansted airport but had to turn back about 20 minutes later when the tape came loose.
The incident was reported in UK newspapers last night and one of the 200 passengers told The Sun it looked like duct tape had been used.
"We were kept in the dark, and we were terrified," Anthony Neal said. "I could see guys taping in the windscreen with what looked like duct tape or gaffer tape."
He said during the flight – bound for Riga, Latvia, the pilot announced they were turning back because of "damage on the windscreen".
But the Irish Aviation Authority says the tape was simply a precautionary measure to secure a new window seal.
A spokesman for the budget airline says approved procedures were followed.
"We do not comment on routine technical issues."
Ryanair has come under fire for its cost-saving measures, which include a proposal to get rid of two out of three toilets on its planes to make room for extra seats.
Source: yahoo