In late 2011, Iridium 94 (27374, 2002-005C) started manouvering.
Its orbital inclination was reduced from 86.5 degrees to 85.9 degrees, so that it drifted away from orbital plane 3.
The intention was evidently to drift it to orbital plane 2, which had been without a spare satellite since Iridium 11 entered the operational constellation in 2010.
The migration to the adjacent orbital place took approximately 12 months.
On 13 November, 2012, Iridium 94 (27374, 2002-005C), which had been migrating over the past year from orbital place 3, arrived at orbital plane 2, and was immediately raised to operational altitude to replace Iridium 23 (24906, 1997-043D) which had evidently failed, though retaining at least some functionality. Iridium 23 remains at operational altitude a few seconds behind Iridium 94