However, the Cottagers are reluctant to finalise the deal until they have found an adequate replacement keeper.
"I can confirm we're in talks with Birmingham about a one-year loan deal," Langham told the official Fulham website.
"Should Birmingham remain in the Premiership at the end of this season, Maik will sign permanently for a substantial fee.
"But I'd like to reassure fans no deal will be done until a suitable number two keeper has been signed."
Veteran keeper Dave Beasant has been offered a position of goalkeeping coach at Fulham, but the club have not disclosed whether or not he will also be offered a playing contract.
The former Wimbledon and Nottingham Forest keeper did, however, keep goal for Fulham in their 2-0 pre-season friendly defeat at Livingston on Tuesday night.
