Singapore Airlines (SIA) has decided to ground one more of its Boeing 747-400 freighters at a desert in California, and does not rule out the possibility that it may park more aircraft if market conditions continue to deteriorate.

The airline says this is the second 747-400 it has taken out of operation; the first was parked in December 2012. The second 747 will be taken out of revenue service from June 2013 to May 2014.

“We will continue to monitor market conditions closely and make further capacity adjustments as required,” says SIA Cargo President Tan Kaiping.

“Fuel prices remain high, and we continue to see weakness in the air cargo market due to industry-wide overcapacity, which has put pressure on rates,” the executive adds.

SIA Cargo announced an operating loss of S$167 million ($132 million) for the fiscal year ending March 31, the worst result of all of SIA’s business units. The grounding means SIA Cargo is left with 11 747-400 freighters in operation, the carrier notes.