Narrative:

While in level cruise at 11000 ft, en route from mke, wi, to sbn, in, I was enjoying a drink of water from a clear, plastic water bottle that I normally carry with me on flts. Suddenly the captain and I smelled smoke in the cockpit. About a second later, I felt an intense burning pain on my left leg. When I looked down, I found the smoke to be coming from my pants leg. The cause of this unusual occurrence also became immediately evident --- the clear water bottle, that I had resting between my legs, had magnified the sunlight coming through the side window. The beam was concentrated right on my left leg near the bottle. At least if a fire had actually been allowed to develop, the emergency procedure would have been quite simple: 1) pull open spout, and 2) squirt. This event has caused me to think of the possible consequences of leaving a water bottle or other clear plastic or glass object on a pilot's seat or console in an unattended aircraft parked outside in the sun.

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Original NASA ASRS Text

Title: BE1900D FO HAS TROUSERS ALMOST SET AFIRE WHEN A BOTTLE OF WATER MAGNIFIED THE SUN AND FOCUSED THE HEAT ON THEM.

Narrative: WHILE IN LEVEL CRUISE AT 11000 FT, ENRTE FROM MKE, WI, TO SBN, IN, I WAS ENJOYING A DRINK OF WATER FROM A CLR, PLASTIC WATER BOTTLE THAT I NORMALLY CARRY WITH ME ON FLTS. SUDDENLY THE CAPT AND I SMELLED SMOKE IN THE COCKPIT. ABOUT A SECOND LATER, I FELT AN INTENSE BURNING PAIN ON MY L LEG. WHEN I LOOKED DOWN, I FOUND THE SMOKE TO BE COMING FROM MY PANTS LEG. THE CAUSE OF THIS UNUSUAL OCCURRENCE ALSO BECAME IMMEDIATELY EVIDENT --- THE CLR WATER BOTTLE, THAT I HAD RESTING BTWN MY LEGS, HAD MAGNIFIED THE SUNLIGHT COMING THROUGH THE SIDE WINDOW. THE BEAM WAS CONCENTRATED RIGHT ON MY L LEG NEAR THE BOTTLE. AT LEAST IF A FIRE HAD ACTUALLY BEEN ALLOWED TO DEVELOP, THE EMER PROC WOULD HAVE BEEN QUITE SIMPLE: 1) PULL OPEN SPOUT, AND 2) SQUIRT. THIS EVENT HAS CAUSED ME TO THINK OF THE POSSIBLE CONSEQUENCES OF LEAVING A WATER BOTTLE OR OTHER CLR PLASTIC OR GLASS OBJECT ON A PLT'S SEAT OR CONSOLE IN AN UNATTENDED ACFT PARKED OUTSIDE IN THE SUN.

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.