The Air India administration had issued the gag order after the Mangalore crash.
Air India Corporation Employees Union (ACEU) General Secretary J B Kadian said the management has issued gag orders against leaders of all unions of Air India.
The orders restrained union leaders from going public with their problems.
Union leaders termed the move as anti -democratic.
A section of the employees of Air India, including engineers, also went on a flash strike to protest delay in payment of salaries and problems relating to the working conditions of cabin crew, union leaders said.
However, an Air India spokesperson claimed that there has been no impact of the strike on flight operations.
"We have begun a flash strike on delay in payment of salaries and the problems of the cabin crew, after the management refused to pay heed to our demands," Kadian said.
Air India had recently decided that the May salaries would be delayed by a week.
Unions belonging to the international wing of Air India have not gone on strike on this issue so far.
The ACEU is part of the Civil Aviation Joint Action Front (CAJAF), a joint platform of 11 recognized trade unions in National Aviation Company of India Limited (NACIL). (ANI)