Carbon Brakes versus Steel.

[novicef]

Is there any website or can anybody enlighten me as to the advantages of Carbon Brakes versus Steel Brakes.

[allthatglitters]

After a Google search some interseting items,
http://www.messier-bugatti.com/rubrique.php3?id_rubrique=47&lang=en
https://www.edwards.af.mil/archive/2004/2004-archive-carbon_brakes.html
http://www.geocities.com/profemery/aviation/carbon_brakes.html

It appears to have been a previous subject here on pprune.

[robin747]

I would like to add here, having seen them perform on the A310 and the B744, they are pretty good being lighter and are 'sensitive' to the amount of application of braking effort and are also sensitive at lower temp [ its inherent characteristics] single smart effort of braking would build up less heat / temp then say a shy braking effort all the way.

They are also sensitive to bad keeping, eg: if cold water is poured on heated brakes for quick cooling, they are known to warp. It needs or prefers cooling fans or else a gentle cooling with or without some conditioned air.Even the messier-bugatti site is silent on this.

[h73kr]

I would like to add here, having seen them perform on the A310 and the B744, they are pretty good being lighter and are 'sensitive' to the amount of application of braking effort and are also sensitive at lower temp [ its inherent characteristics] single smart effort of braking would build up less heat / temp then say a shy braking effort all the way.

They are also sensitive to bad keeping, eg: if cold water is poured on heated brakes for quick cooling, they are known to warp. It needs or prefers cooling fans or else a gentle cooling with or without some conditioned air.Even the messier-bugatti site is silent on this.

Whoa there, please NEVER allow or suggest any kind of cold liquid cooling for any kind of overheated aircraft brakes! If you do, at least let me know so I can take steps, large ones, in the opposite direction. Never mind warp, sudden explosive shatter is more likely! :ooh: Otherwise, yep, carbon much lighter, less brake fade and heat accumulation, but very prone to softening/degradation from oil absorption/contamination etc.

[robin747]

h73KR... you taking a step back on those counts is understandable [ water therapy I call it - sic] the ground reality if you have flown in the mid-east and SE Asia, this is what we could encounter for quick cooling... unless its insisted none such therapy and the delay is acceptable in the absence of cooling conditioned air.

[h73kr]

h73KR... you taking a step back on those counts is understandable [ water therapy I call it - sic] the ground reality if you have flown in the mid-east and SE Asia, this is what we could encounter for quick cooling... unless its insisted none such therapy and the delay is acceptable in the absence of cooling conditioned air.

Understood, just didn't want anyone reading to think it was an accepted, safe, or recommended practice, bit like a few days ago when on another thread it was suggested that phones could be more hazardous than smoking in the toilet! :ooh:

[Pilot Pete]

Flown 757s with both. Carbon more 'fierce' during taxy out braking, better on landing when hot. A point to note is that autobrake setting 1 meant that they were not heating up sufficiently towards optimum and therefore wearing more quickly, so the company made it SOP to use a minimum of autobrake 2.

PP

[Miles Magister]

Some of the videos here http://www.aircraftbraking.com/SUP_Videos.php are quite good but they seem to want some drinking vouchers in exchange.

I believe the British Aerospace test pilots aledgedly found some interesting data when testing carbon brakes on the 146/RJ which is worth listening to. It was something along the lines of they are not very good and suffer excessive wear up to about 250 Deg C (Quite normal), are effective from 250 to around 600 Dec C, but then fade quite rapidly as the carbon gas pressure builds up between the plates at very high temperatures. However this is third hand information so do not use it as training or operational information. Perhaps a TP with better knowledge than I would care to comment?