Epidemic of cracked windshields in KDEN, explanation unknown

I think the newsgroup would be interested in this finding.

"Although windborne debris was at first dismissed as a cause for the
14 cracked aircraft windshields last week at Denver International
Airport, investigators now are saying FOD, or foreign-object debris,
was indeed to blame. Microscopic analysis showed fine particles caused
pitting that in turn caused cracking, NTSB investigator Jennifer
Kaiser told the Denver Post. The runways had been sanded during recent
snowstorms, and it's suspected that the winds, gusting up to 48 mph,
drove the fine sand particles into the windshields. The fractures
affected six passenger jets as they were taking off, seven on the
airport surface, and one at 19,000 feet. The NTSB offered no
explanation regarding that high-altitude incident. Also unexplained
was the apparent lack of damage to any aircraft surfaces other than
windscreens. "The only commonality across aircraft type, operator,
location, time and phase of flight was the wind and weather," Kaiser
told the Post.


groupOn Feb 18, 9:27 pm, wrote:
On Feb 17, 5:07 pm, Blanche wrote:

Winds on Thursday & Friday reached over 100 mph in the foothills.
We don't use salt, as a rule, on the roads. Ice slicer and a
combination of fine rocks. Add to this the everyday, run-of-the-mill
rocks and gravel kicked up on the roads, and it's normal to replace
thewindshieldsevery 2-4 years (I'm due this year. Last change
was in 2004). Get these winds, a few hefty rocks, and
a new windshield sooner than expected.

KDEN is surrounded by empty fields (for the most part), which means
lots of "stuff" in the area that is kicked up by the winds.

Boulder is a town just north ofDenver, right at the foothills, which
are steep and abrupt.
Sometime in the late 80s or early 90s, a windstorm from the west blew
out nearly all of the front and back autowindshieldsin a parking
lot. IIRC it wasn't debris, but the wind itself. It gets to howling
there some times.

Probably nothing to do with the current situation, though. I'd have
to think that a wind that strong would also bend the airplanes up a
bit.

Where is Richard Feynman when you need him to explain what the
'experts' can't....

denny

Isn't sanding areas at an airport kind of a bad idea, precisely because sand
could be FOD?

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