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nick14
29th Oct 2012, 16:42
There is a discussion plaguing our pilot body at present regarding brake cooling and what it is protecting you against.

One answer is that the figures in the advisory information protect you for a turn around and subsequent RTO, ie allowing sufficient energy absorption capability of the brakes following a landing.

The other rumour is that it protects you for a subsequent air return @ mtow.

Does anybody have any suggestions for us on boeings intent for this information?

Thanks

Cockelshell
29th Oct 2012, 19:33
hi, two charts

Maximum Quick Turnaround Time Dispatch

After landing at weights exceeding those in the table,
adjusted for slope and wind, wait at least 67 minutes and
check that wheel thermal plugs have not melted before
executing a takeoff.

This time only addresses wheel fuse plug melt issues

The time does not imply that the brakes will have cooled
down sufficiently to absorb the energy of an RTO
Time dependent on airplane, wheel, brake configuration

Brake Cooling Chart Inflight

Brake cooling chart provides recommended cooling
times to decrease the residual brake energy to a
level low enough to avoid tire deflation on
subsequent landings

Times do not ensure that the brakes will be cool
enough to absorb the energy resulting from a high
energy RTO.

Any help?

nick14
30th Oct 2012, 09:05
Good advice thanks.

From what you have written it looks as if there is no information to ensure you have sufficient capacity in the brakes for an RTO which is the impression I got from what I have read so far in the various manuals.

Above all its ADVISORY information so Boeing can always wash their hands of any accident.

FLX/MCT
30th Oct 2012, 17:02
Taking into account jet transport airplanes in general, could you provide me any official information how increased brake temperature will adversely affect landing distance or ASD? I have been looking for information for some time but only found the well known statement that heated brakes might not able to absord sufficint energy? Do you have anything more specific?

Regards,

Luke

Skyjob
3rd Nov 2012, 01:14
Here is a presentation from Boeing on the issue, a bit dated (2003) but valid. Or search for w100g.1 in Google, should be somewhere on top of list.

http://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=3&cad=rja&ved=0CD4QFjAC&url=http%3A%2F%2Fwww.smartcockpit.com%2Fdownload.php%3Fpath% 3Ddocs%2F%26file%3DBrake_Energy_Consideration_In_Flight_Oper ation.pdf&ei=sm6UUOvyKYyW0QWv_YGoDg&usg=AFQjCNGwlLBMicuLdXvb5D7xpbCLiibazw