Convection columns and cracked air tanker windshields

Here is an excerpt from an article published this morning at Wildfire Today about the Delta Fire north of Redding, California.

“…There was no overnight mapping by a fixed wing aircraft Thursday night. One of the two U.S. Forest Service infrared scanning planes was down with mechanical difficulties, which could be the reason for the “unable to fill”. It was smoky over the fire during the night but that usually does not prevent imaging the fire, unlike clouds which prevent the infrared light from reaching the sensor on the aircraft. The ability to “see” through smoke is one of the primary attributes of infrared sensing technology. However an intense convection column containing smoke, ash, and burning embers can be confused with heat on the ground.

“During the large vegetation fires in southern California in 2003 some of the convection columns were so powerful that the windshields on six air tankers were cracked by chunks of debris that were being hurled into the air (page D-6 in 2003 California Governor’s Blue Ribbon Report; huge 20 Mb file). One pilot saw a four by eight sheet of plywood sail past at 1,500 feet.”

Do any of our readers who are pilots have similar experiences?

3 thoughts on “Convection columns and cracked air tanker windshields”

  1. I’ve definitely seen some big stuff flying around in fires, including branches and big chunks of trees, as well as some really big birds (which were not on fire). Areas around fire whirls or rotational activity are driven by rapidly rising air in a column of low pressure which can draft all kinds of material up into the column; this can fall out of the column, too, and has the potential to cause damage.

  2. I don’t have a link however during Johnson Fire on the Fish Lake NF, Utah (2002) there is video I know to exist of a helitanker flying alongside a rotating convection column. There are clearly visible, branch sized debris falling as the ship passes from camera view.

    I believe the Dixie Hotshots may have the source tape. If not and someone cares to see it, I may have a useful copy.

  3. Yes, i remember. Front panes were pitted at 90%. Unable to look ahead. Leading edges got “sandblasted” and paint removed… Happened in few seconds.
    Interesting times.

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