As Jet Airways continue to ground aircraft and cancel significant number of flights, the airline’s aircraft maintenance engineers' union wrote to the aviation regulator on Tuesday that three months of salary was overdue to them and flight safety "is at risk".

In a letter written to the Directorate General of Civil Aviation, Jet Aircraft Engineers Welfare Association (JAMEWA) stated: "It has been arduous for us to meet our financial requirements, result of which have adversely affected the psychological condition of Aircraft Engineers at work and therefore the safety of public transport airplanes being flown by Jet Airways across India and the world is at risk."

"While the senior management is finding a resolution to be in business, we the Engineers who inspect, troubleshoot and certify the public transport airplanes for its airworthiness are in tremendous stress due to non-payment of salaries on time, since last 7 months. As of now, 3 month's salary is overdue to us," the letter, which has been accessed by PTI, said.

Cash-strapped Jet Airways had on Monday said it had grounded four more planes, taking the number of aircraft that are non-operational due to non-payment of lease rentals to 41.