Narrative:

We departed for our destination. Shortly after leveling at FL380 we heard a very loud sound like a bird or rock impacting the windshield. My windshield (captain; front L-1) severely cracked; especially on the bottom third. We tightened our seatbelts and asked ATC for a lower altitude. I then noted arcing near the bottom of the windshield. We ran the QRH checklist and confirmed it was the outer pane. My visibility was substantially diminished; especially the lower portion where I am looking mostly. We informed the flight attendants and received a phone patch with dispatch for advice on returning to our departure airport or an alternate. Dispatch advised the alternate. I explained the situation to the passengers and proceeded uneventfully without declaring an emergency. Operations had a spare aircraft for us next door and we proceeded to our scheduled destination after a 50-minute delay.

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Original NASA ASRS Text

Title: A B737-700 Captain reported that the Captain's L-1 outer windshield pane cracked after leveling at FL380.

Narrative: We departed for our destination. Shortly after leveling at FL380 we heard a very loud sound like a bird or rock impacting the windshield. My windshield (Captain; front L-1) severely cracked; especially on the bottom third. We tightened our seatbelts and asked ATC for a lower altitude. I then noted arcing near the bottom of the windshield. We ran the QRH checklist and confirmed it was the outer pane. My visibility was substantially diminished; especially the lower portion where I am looking mostly. We informed the Flight Attendants and received a phone patch with Dispatch for advice on returning to our departure airport or an alternate. Dispatch advised the alternate. I explained the situation to the passengers and proceeded uneventfully without declaring an emergency. Operations had a spare aircraft for us next door and we proceeded to our scheduled destination after a 50-minute delay.

Data retrieved from NASA's ASRS site as of April 2012 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.