Airbus autobrakes
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Joined: Sep 2002
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From: zz plural 5
Airbus autobrakes
I fly a first generation airbus widebody.When using autobrake I sometimes cancel it early to make an appropriate turn-off.Sometimes I find that the result of this is full braking on one side and very little braking on the other!!Has anybody had any similiar experiences?
Joined: Aug 2002
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From: Switzerland, Singapore
This happens also on other types. Also if you keep the autobrake on, you will see that with crosswind, the autobrake brakes on one side more than on the other. Evidence gives you the brake temperatur a few moments later.
If it happens several times on different runways with different wind conditions, you might want to talk with an engineer.
If it happens several times on different runways with different wind conditions, you might want to talk with an engineer.
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Joined: Sep 2002
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From: zz plural 5
I had this the other evening on a long runway with virtually calm wind, 3 kts.One set of brakes were 300c hotter than the other side as we turned off.At the end of the landing run I had my leg virtually straight on the cold side with all the breaking on the other that I was barely touching!Cold side was the side the wind was coming from.I have also had this on the same type,but different aircraft on a short runway following a steep non precision approach-that time the brakes got to 540c and 80c!
Joined: Nov 2003
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From: ireland
On the 146 if you had a 300 degree difference in brake temp's on the same axle the chaces were that the brake with the lower temp the inner stators had let go and the brake wasnt working. You wouldn't see this on a walk around because the stator in contact with the brake pistons usually was the strongest and very seldom failed.
The amount of brake wear can have an effect on brake temp's also. A new brake unit has more material to absorb heat but one almost worn to limits will run hotter because of less material.
Also on tha Airbus's it isn't advisable to change the two brake units on the one axle at the same time as there was a theory that a new carbon brake required about 100 cycles to start to operate at full efficency.
Auto brake's hide the above and it's only when you switch it off that the above starts to show up.
I hope this has been some help.
The amount of brake wear can have an effect on brake temp's also. A new brake unit has more material to absorb heat but one almost worn to limits will run hotter because of less material.
Also on tha Airbus's it isn't advisable to change the two brake units on the one axle at the same time as there was a theory that a new carbon brake required about 100 cycles to start to operate at full efficency.
Auto brake's hide the above and it's only when you switch it off that the above starts to show up.
I hope this has been some help.
Joined: Jan 2004
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From: mostly on earth
Weather Vane factor
That is But why the brakes on the non-wind side tend to have a higher temperature. Coz the Auto brakes apply on the lee-ward side to counteract for the weather vaning into the wind- ward ( upwind ) side.
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From: UK
Interesting. The downwind brakes will always be hotter than the upwind, but 300C difference does seem excessive. One possible explanation for your light x-wind experience the other night could be that you were braking hard on the downwind side and having to compensate with excessive rudder input on the upwind side, hence the straight leg. Alternatively you could be doing everything right and the aircraft could be broke!
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From: zz plural 5
One of our aircraft had a brake master valve changed recently but this problem seems to occur randomly across the fleet.It only ever seems to occur when using autobrake and then cancelling it.
