Sandeep Verma and V K Khosla stepped down last Friday, sources said today.
While Verma was heading the operations and was associated with SpiceJet since its inception in 2005, Khosla was head of flight safety, they said.
Exit of some more "highly-paid" executives was likely in the coming months due to focus on cost-rationalisation, a SpiceJet official had said after its Information technology chief Sudhakar Kondisetty's departure last month.
The then SpiceJet managing director, S Natrajhen, was the first top official exiting the carrier soon after Singh came onboard.
Since then the airline has seen the resignation of six more senior executives including Kaneswaran Avili, who stepped down from the chief commercial officer's position about two months ago.
Singh had acquired the entire 58.4 per cent from the erstwhile promoter Maran family under a revival plan which entails an investment of Rs 1,500 crore in a phased manner by the new promoter.
The airline reported a net profit of Rs 22.51 crore in the January-March period of the last fiscal after flying into red zone for seven quarters.