LATAM B773 complete electrical failure?
Join Date: Aug 2008
Location: Moscow
Age: 44
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What I found really unexpected, that report says
that's 65 tons of water to control the wheel fire. Seems quite a bit more than I would expect.
During landing, the brake set overheated, which started the fire on the wheels of the
main right and left landing gears. The Fire Section carried out the fire fighting, which was controlled in 4 minutes. From the beginning of the fire extinguishing to cooling the set of brakes, 65,700 liters of water and 780 liters of Foam Generating Liquid (LGE) have been spent.
main right and left landing gears. The Fire Section carried out the fire fighting, which was controlled in 4 minutes. From the beginning of the fire extinguishing to cooling the set of brakes, 65,700 liters of water and 780 liters of Foam Generating Liquid (LGE) have been spent.
Join Date: Nov 2003
Location: Germany
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Water usage
I think that´s fully ok. The wheels are big and many, and the brakes: same. Plus, they carry all the heat from braking the overweight airplane in them. Amazing, that they could take it, anyway.
So, a quantity of water is needed to cool things down. Quite ok with me.
So, a quantity of water is needed to cool things down. Quite ok with me.
65 tonnes = 65 cubic meters. Or a swimming pool about 5.5m x 6m x 1.96m deep (water is pretty massive). Doesn't seem like a lot to me, given the mass of the main gear trucks (~6.8 tonnes each).
Plus it occured in local tropical summertime. Daily high temperatures of 28°C - the water may have been 25-35°C after sitting in the sun all day, and thus less efficient in absorbing and removing heat from the metal/rubber/carbon of the gear.
One would have to juggle starting temps, specific heats, joules, volumes/masses and such to get an estimate of water required to achieve cooling of xx°C. And then factor in inefficiency of delivery (water that just sprays on the runway).
Plus it occured in local tropical summertime. Daily high temperatures of 28°C - the water may have been 25-35°C after sitting in the sun all day, and thus less efficient in absorbing and removing heat from the metal/rubber/carbon of the gear.
One would have to juggle starting temps, specific heats, joules, volumes/masses and such to get an estimate of water required to achieve cooling of xx°C. And then factor in inefficiency of delivery (water that just sprays on the runway).
By my math, it would take something like 300 tonnes of steel at 1100 degrees Celsius to flash 65 tonnes of 100 degree water to 100 degree steam. So it seems safe to say the runway got pretty wet.
