The city-state's flag carrier has been battling strong competition from Asian low-cost carriers and Middle Eastern airlines, which now boast modern fleets and top-quality inflight services.
The airline, which posted a net loss in the fourth quarter of the last financial year, has launched a wide-ranging review and refused to rule out job cuts.
The company said it had offered its cabin crew the option of taking unpaid leave between September and November this year due to a "temporary surplus of crew".
"Having temporary surpluses or deficits of cabin crew is not unusual due to the nature of our business, and this voluntary scheme over a specific period of time is to ensure that we efficiently manage crew resources and operational requirements," a spokesman said.
The spokesman added the airline now plans to offer the option from time to time in the future.
It last resorted to the measure in 2009, after the global financial crisis.
Aviation analyst Shukor Yusof of Endau Analytics told AFP it showed "legacy carriers" were finding it harder to survive.
"(Singapore Airlines's) business travel segment has been hit hard and more are turning to low cost carriers," he said.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)