The flight crew of a B757-200 assumed a cracked captain's windshield was not an emergency item but l...

Narrative:

We were cruising at fl 390 approximately 25 NM west of tcc when we saw what looked like st. Elmo's fire flash across the L-1 windscreen. It seemed rather odd since we were in VMC conditions and hundreds of miles from any clouds. Then within 10-15 seconds; we saw light smoke accompanied by a very bright orange streak moving from the upper right (where it looks like the window heat electrical plug connects) to the lower left. Even though we never got an overheat caution light to illuminate; we immediately turned off the window heat switch for L-1. Next we saw two cracks on the outer pane of the windscreen. The first was caused by the initial orange streak and the second began from the middle of the upper portion all the way down to the bottom of the pane. We then referenced the window damage QRH. While reading the checklist; we determined that the cracks were to the outer pane and that the differential pressure restrictions did not apply. The final statement in the QRH for an outer pane crack is to 'continue normal operation.' however; to err on the conservative side; we requested a descent with center to fl 240 and began a 1000 fpm descent. I then notified the flight attendants that we had an issue with the forward windscreen and that we were beginning a shallow descent. I also announced to the passengers that the seatbelt sign was coming on; but did not tell them of our problem. We then continued our descent with the fort worth center and landed uneventfully at our planned destinationi did not fully grasp the seriousness of this situation until the next day when I read an article that stated that there have been a number of 'window fires' in boeing 757/67 aircraft; and also faulted the crews for not diverting. After reading that article; I realized that with seeing smoke and the orange streak; we too had experienced a window fire. I think that the information in the QRH needs to be expanded in order to distinguish between a regular crack and a fire. Perhaps a boxed/immediate action could be added to have the crew turn off the window heat switch at the first sign of smoke/fire indications. Perhaps our safety team in conjunction with boeing could investigate if this condition requires the crew to land as soon as practical.

Original NASA ASRS Text

Title: The Flight Crew of a B757-200 assumed a cracked Captain's windshield was not an emergency item but later learned that the actual event was an electrically initiated fire that has plagued the fleet of late.

Narrative: We were cruising at FL 390 approximately 25 NM west of TCC when we saw what looked like St. Elmo's fire flash across the L-1 windscreen. It seemed rather odd since we were in VMC conditions and hundreds of miles from any clouds. Then within 10-15 seconds; we saw light smoke accompanied by a very bright orange streak moving from the upper right (where it looks like the window heat electrical plug connects) to the lower left. Even though we never got an Overheat Caution light to illuminate; we immediately turned off the window heat switch for L-1. Next we saw two cracks on the outer pane of the windscreen. The first was caused by the initial orange streak and the second began from the middle of the upper portion all the way down to the bottom of the pane. We then referenced the Window Damage QRH. While reading the checklist; we determined that the cracks were to the outer pane and that the differential pressure restrictions did not apply. The final statement in the QRH for an outer pane crack is to 'Continue Normal Operation.' However; to err on the conservative side; we requested a descent with Center to FL 240 and began a 1000 fpm descent. I then notified the Flight Attendants that we had an issue with the forward windscreen and that we were beginning a shallow descent. I also announced to the Passengers that the seatbelt sign was coming on; but did not tell them of our problem. We then continued our descent with the Fort Worth Center and landed uneventfully at our planned destinationI did not fully grasp the seriousness of this situation until the next day when I read an article that stated that there have been a number of 'window fires' in Boeing 757/67 aircraft; and also faulted the Crews for not diverting. After reading that article; I realized that with seeing smoke and the orange streak; we too had experienced a window fire. I think that the information in the QRH needs to be expanded in order to distinguish between a regular crack and a fire. Perhaps a boxed/immediate action could be added to have the Crew turn off the window heat switch at the first sign of smoke/fire indications. Perhaps our Safety Team in conjunction with Boeing could investigate if this condition requires the Crew to land as soon as practical.

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.

Attributes
ACN	942801
Time
Date	201103
Local Time Of Day	0001-0600
Place
Locale Reference	ZAB.ARTCC
State Reference	NM
Aircraft 1
Make Model Name	B737-700
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Flight Plan	IFR
Component
Aircraft Component	Cockpit Window
Person 1
Function	Captain
Qualification	Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 225 Flight Crew Type 11000
Events
Anomaly	Aircraft Equipment Problem Critical Flight Deck / Cabin / Aircraft Event Smoke / Fire / Fumes / Odor

The flight crew of a B757-200 assumed a cracked captain's windshield was not an emergency item but later learned that the actual event was an electrically initiated fire that has plagued the fleet of late.