National passenger carrier Air India has lost 50 pilots, who have tendered in their resignation this year, the Rajya Sabha was told Tuesday.Minister of State for Civil Aviation Mahesh Sharma informed the the upper house of parliament: "In this year, 50 pilots have tendered resignation from the services of Air India."When asked about a shortage of air hostesses for more than 70 domestic and 16 international flights, the minister accepted that the national carrier has been facing an acute shortage of cabin crew for both domestic and international routes.