Windshield damage on a Cessna 441 Conquest can be hiding on you. During an inspection, the area that can be easily overlooked is just under the hot air discharge ducting at the base of the left and right windshields. Hot air from the anti-icing discharge ducts can cause streaking, grooving and heavy crazing to the exterior surface of the windshield. Usually the crazing is hiding and difficult to see because there isn’t enough light under the duct cover to inspect the area correctly.
From the cockpit, use a strong lamp to get light under the ducting to inspect that area. Crazing is often hiding there and can be very deep. Cessna does call out in the maintenance manual that crazing is not acceptable damage on the windshield. It must be addressed for continued airworthiness.
We notified the customer of this hidden damage and after a complete inspection, we were unable to save the windshield because the crazing had happening for too long of a period of time. A new windshield was ordered.
The sooner crazing is recognized and repaired, the better and longer you can maintain a windshield. Many turboprop and turbine powered aircraft use bleed air discharge on windshields for anti- and de-ice applications. Excess heat from this type of system will cause damage.
If you have questions about what crazing looks like or where it comes from, please give us a call. We’ll talk you through what to look for to treat the damage. 877-303-0709 or email us - Bruce@newviewtech.com.