In a fresh bout of turbulence for Jet Airways, the engineers of the airline have now indicated that they will stop maintaining the inactive fleet of over 80 planes from April 1 as pending salary dues have still not been paid.

Sources close the development have told CNBC-TV18 that the engineering department held a meeting today and decided that they will no longer "work for free."

This would put a question mark on the lease agreements of 54 planes which are grounded on account of non-payment of lease rentals by the airline.

“The engineers have said that they will not maintain the inactive fleet from April 1 as they are not willing to work for free. While 30-odd planes are not airworthy and need heavy maintenance, the remaining inactive fleet also needs some light maintenance on a daily scale. This could potentially lead to grounding of the entire airline," one of the sources aware of the development said.

The airline currently has an active fleet of 35 planes with two-thirds of its total count of 119 planes on the ground. The beleaguered airline recently made an ambitious claim to the union civil aviation ministry of adding 40 more planes to its fleet by April end.

"With engineers not ready to maintain the grounded planes, the lessors are likely to get more anxious and the negotiations for activating those planes may face more hurdles," another source said on condition of anonymity.

The decision comes a day after the pilot union of the airline, National Aviators Guild, released a statement that they will stop flying from April 1 as a part of the expected interim funding has not been infused into the airline and long-term plan for sustainable operations of the airline have not been conveyed to them.

It is learnt that senior management, pilots and engineers were promised of an immediate fund infusion of Rs 250 crore by March 29 to aid in payment of their dues.

However, with no such infusion in place, pilots not only await their pending dues but also a long-term plan by the lenders on fund infusion and survival of the airline.

"Salary dues of senior management, pilots and engineers for the last three months now stand at around Rs 330 crore in April this will increase to Rs 440 crore. We want to know how much will the lenders pay to vendors, lessors, employees and how do they plan to sustain an airline...there is no clarity and just a lot of rumours," another person said.

The consortium of banks led by State Bank of India is expected to announce the interim committee for Jet Airways on Monday, sources said. The committee is expected to run the operations at the Mumbai-based carrier till they find a suitable investor by the end of June quarter.

However, if the lenders are unable to convince the pilots and engineers before March 31, the interim committee will just have planes to manage.