[VoiceOps] Single fan loss cause netra meltdown?

Have you ever run a netra 240 or 440 with one fan out of service? I saw a notice today that indicates that the thing will eventually overheat if only one fan dies. The notice did not mention any specifics about the ambient temp or airflow conditions. If this were a common occurrence, you'd think that it would have gotten more press by now. Thanks, David