Narrative:

I already sent a report due to declaring an emergency and diverting to ZZZ, but I wanted to identify a safety issue. The F100 cracked window procedure is not very helpful. At FL330 in the dark, the windshield arced. We turned off the heat per arcing checklist, then went to the cracked window procedure. First, it was very difficult to determine which pane cracked. I could not feel the crack, so I knew it wasn't the inner, but that was all I could determine. The second bullet says if inner or middle layer is cracked, no action required. Does this refer only to the heat and airspeed mentioned above, or does this mean ok to continue. The note goes on to say that the center pane is structural, but mentions nothing about landing when practical. In the heat of battle in the dark, this is all contradictory and confusing. When we started to get additional cracks, we declared an emergency with ARTCC when we requested vectors. And diverted. Callback conversation with reporter revealed the following information: reporter stated that there was no way to determine which layer of the window was cracked. The manual did say that the middle layer is structural, but then had no information on what to do about it. The reporter would like the checklist to contain a way to determine which layer is cracked, then have clear instructions on what to do. Airspeeds to follow, and whether or not to land would be good information to have in the flight manual.

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Original NASA ASRS Text

Title: AN F100 FLT CREW EXPERIENCES A CRACKED WINDSHIELD AND IS CONCERNED WITH THE LACK OF INFO IN THE FLT MANUAL.

Narrative: I ALREADY SENT A RPT DUE TO DECLARING AN EMER AND DIVERTING TO ZZZ, BUT I WANTED TO IDENTIFY A SAFETY ISSUE. THE F100 CRACKED WINDOW PROCEDURE IS NOT VERY HELPFUL. AT FL330 IN THE DARK, THE WINDSHIELD ARCED. WE TURNED OFF THE HEAT PER ARCING CHKLIST, THEN WENT TO THE CRACKED WINDOW PROC. FIRST, IT WAS VERY DIFFICULT TO DETERMINE WHICH PANE CRACKED. I COULD NOT FEEL THE CRACK, SO I KNEW IT WASN'T THE INNER, BUT THAT WAS ALL I COULD DETERMINE. THE SECOND BULLET SAYS IF INNER OR MIDDLE LAYER IS CRACKED, NO ACTION REQUIRED. DOES THIS REFER ONLY TO THE HEAT AND AIRSPEED MENTIONED ABOVE, OR DOES THIS MEAN OK TO CONTINUE. THE NOTE GOES ON TO SAY THAT THE CENTER PANE IS STRUCTURAL, BUT MENTIONS NOTHING ABOUT LNDG WHEN PRACTICAL. IN THE HEAT OF BATTLE IN THE DARK, THIS IS ALL CONTRADICTORY AND CONFUSING. WHEN WE STARTED TO GET ADDITIONAL CRACKS, WE DECLARED AN EMER WITH ARTCC WHEN WE REQUESTED VECTORS. AND DIVERTED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THAT THERE WAS NO WAY TO DETERMINE WHICH LAYER OF THE WINDOW WAS CRACKED. THE MANUAL DID SAY THAT THE MIDDLE LAYER IS STRUCTURAL, BUT THEN HAD NO INFO ON WHAT TO DO ABOUT IT. THE RPTR WOULD LIKE THE CHKLIST TO CONTAIN A WAY TO DETERMINE WHICH LAYER IS CRACKED, THEN HAVE CLEAR INSTRUCTIONS ON WHAT TO DO. AIRSPEEDS TO FOLLOW, AND WHETHER OR NOT TO LAND WOULD BE GOOD INFO TO HAVE IN THE FLT MANUAL.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.