As temperatures climb and summer approaches, Challenger operators based in high-humidity locations may notice the accumulation of moisture on cabin windows.  This fogging of the cabin windows common in high heat/humidity areas, can be a nuisance for passengers.

A Bombardier Reference Information Letter (RIL) CL-0081 has been issued for the removal of this condensation.  The process is applicable to Challenger 600, 601, 604, 605 and 650 model aircraft and can be done on an as needed basis.  

The RIL outlines the process, which involves flushing the cabin window space with liquid nitrogen through the weep hole.