Hello Joshua,
Cracks in fan blades has historically been an issue on A framed ACCs through many years. It is a forced draft arrangement and on the windward side of the ACC the air flowing into the fans is turbulent creating almost a cavitation effect. At high ambient wind speeds there can be a downdraft on the windward side and a updraft on the leeward side. So as the fan blades rotate inside of the fan bell the blades are being stressed which over time can fatigue the fiberglass laminate and result in blade cracking. Galebreaker offers perimeter mounted wind screens which causes the airflow on the wind ward side to be more uniform , thus resulting in less stress on the fan blades. We are installing this concept on 4 ACCs starting this week which had blade stress issues. Sorry to hear about your problem and you can discuss further with me at gmirsky@galebreaker.com