Most sections of employees in Air India are part of some union, this includes Flight Attendants, Engineers,Ground Supporort etc.
Being a Public Sector Undertaking the employee to aircraft ratio is higher than industry standards, i dont have the exact figures but it it substantially lower than 500 per aircraft.
However lately the management is addressing the issue about overstaffing through schemes such as offering voluntary retirements.
Till 3 years ago the fleet strength of Air India was in the region of 20-30 aircrafts, with the ongoing fleet expansion the employee to aircraft ratio will be further rationalised.
An important point also is that unlike most airlines in India which out source a lot of ground support services and maintanance services,nearly all of the operations of Air India are conducted in house.Air India also provides these services to a host of foreign airlines flying in to India.