OPNLguy From , joined Dec 1969, posts, RR: Reply 5, posted (9 years 2 months 2 weeks 3 days 3 hours ago) and read 2989 times:
>>>And may I say that spelling it "autobrEaking" cracks me up
We commonly see the same thing each winter when we get "breaking action reports" from some stations. If the "breaking" action is reported, I guess it means that the "braking" action isn't very good, and there's one off the end somewhere in pieces...
OPNLguy From , joined Dec 1969, posts, RR: Reply 8, posted (9 years 2 months 2 weeks 3 days 2 hours ago) and read 2892 times:
>>>Sorry for not being perfect,
Believe me, you're not the first person to confuse break/brake, and you certainly won't be the last. I don't think anyone was trying to imply that you weren't perfect (and NOBODY is), but were just trying to see that there is a difference. Were you to use "break" instead of "brake" during some point in an aviation career, someone higher up in the food chain might conclude that you were "unclear on the concept" or something. You'd rather know -now-, from freinds here on A.net, right?
B747skipper From , joined Dec 1969, posts, RR: Reply 11, posted (9 years 2 months 2 weeks 2 days 15 hours ago) and read 2757 times:
Autobrake 1-2-3-4-MAX on modern airplanes, and...
Autobrake MIN-MED-MAX on my dinosaur 747-200s or 300s select a "rate" of deceleration by applying brakes. In both cases of MAX - 3,000 psi of hydraulic pressure is sent to the brakes for stopping the airplane, i.e. in emergency.
What is another fact is when selecting MIN (or A/B-1), with little deceleration required, if you use "full reversers" for that landing, chances are that the brakes will not even be applied, until... you get "out" of using reversers.
BMAbound From Sweden, joined Nov 2003, 660 posts, RR: 5 Reply 14, posted (9 years 2 months 2 weeks 2 days 9 hours ago) and read 2646 times:
I was just wondering, is 4 or MAX really used for wet/icy conditions? To me, the chances of hydroplaning/skidding off the runway seem to increase if pilots are braking hard right after touchdown on a rainy day.
B747skipper From , joined Dec 1969, posts, RR: Reply 18, posted (9 years 2 months 4 days 5 hours ago) and read 2375 times:
RTO position - Rejected Take-Off...
When armed, with RTO ON, if you slam your throttles closed, you get MAX brakes...
Spoilers deploy also at the same time... while you get busy getting these reversers...
Mr Spaceman From Canada, joined Mar 2001, 2780 posts, RR: 15 Reply 20, posted (9 years 2 months 4 days 3 hours ago) and read 2331 times:
I've never seen any type of airliner rolling out after landing with smoke rising from some of the brakes, as can be seen in this photo, so I don't believe this BA 747's brakes are experiencing a normal situation.
What do you guys think would have caused these brakes to smoke like this? High pressure braking action or a mechanical problem?
Perhaps a set of brakes got locked up for some reason. Whatever the cause, I wonder if these brakes would cause a delayed turn-around so they had time to cool off?
AJ From Australia, joined Nov 1999, 2376 posts, RR: 27 Reply 21, posted (9 years 2 months 4 days 3 hours ago) and read 2328 times:
Alvin, on the 767 the RTO function of the autobrakes is activated passing 85kt groundspeed.
Chris, recently serviced brakes can smoke like that if excess grease/dust similar remains in the brake area.
Carbon brakes thrive in the heat, so the high temperatures can cause foreign materials to burn off after application. This is generally a short lived phenomenon. There is a limit of course, get the brakes too hot and you can wind up blowing the fuse plugs on your tires...embarassing and dangerous! It also increases the downtime of the aircraft having hot brakes, as they must have cooled sufficiently to allow the RTO function to effectively operate on the next takeoff. Fans are sometimes used during short turnarounds to help cool hot brakes.
AJ From Australia, joined Nov 1999, 2376 posts, RR: 27 Reply 23, posted (9 years 2 months 4 days 2 hours ago) and read 2306 times:
Yes, the brake temperatures are displayed in values from 0 to 9. A Brake Temp light illuminates for values of 5 or above. Releasing the parking brake (on chocks of course) can help reduce brake temperatures.
If the Brake Temp light comes on for the next takeoff a table entitled 'Max Quick Turnaround Limits' is consulted. A minimum turnaround time of 75 minutes must be applied (would cause chaos on a Cityfler!).
The table limits the takeoff weight for the next flight. For example after a Flap 30 landing at Sydney on a 20 degree day the next takeoff weight with hot brakes is limited to 149,000kg.
Mr.BA From Singapore, joined Sep 2000, 3423 posts, RR: 23 Reply 24, posted (9 years 2 months 3 days 23 hours ago) and read 2281 times:
Thanks AJ for the imput. I don't know if many airlines do this... would it be viable to use more reversers (definately more than idle) during hot days and fast turnaround time? I guess that would ease a lot of pressure on the brakes upon rollout?
I note that cost-saving carriers like Swiss always use full reversers for landings. I don't think it saves more money than using more brakes?
25 B747skipper: The RTO gets automatically armed at 80 Kts during takeoff for a 747. xxx As far as brake temperature gages... we have gages with green, yellow and red
26 Cx flyboy: On the 777, we use Autobrake 2, 3 and sometimes 4 for a short runway like Fukuoka or Nagoya when wet. For long runways we used to use Autobrake 1, but
27 Mr spaceman: Hi guys. > AJ & B747skipper, Thanks for explaining that seeing smoke from the brakes is normal after maintenance has serviced the brakes or installed