Question about new offset 32F9

[jan737]

Hi Pete,

I like to use the new offset, but I can't see how.

32F9 (one byte) is set non-zero when the brakes are used. This could be accessed to determine when to automatically disengage auto-brakes, for instance.

I want to blink the Autobrake disarm light, when the aircraft is autobraking and the speed is dropt to 80 Knts.

Is this possible with this new offset and how can I set up this in Pmsystem?

Best regards

Jan Geurtsen.

[Pete Dowson]

I want to blink the Autobrake disarm light, when the aircraft is autobraking and the speed is dropt to 80 Knts.

Is this possible with this new offset and how can I set up this in Pmsystem?

No, not at all. You are not reading it as it is written. During autobraking, operating manual brakes should stop the autobrakes. This is what this facility is for -- so you can disarm automatically by pressing your brake pedals.

I cannot actually tell when autobrakes are in use. All I can tell is when manual braking is used, and this is the indication you get. I do think this is actually what it says, if you read it again:

32F9 (one byte) is set non-zero when the brakes are used. This could be accessed to determine when to automatically disengage auto-brakes, for instance.

BTW, I don't know what aircraft you are modelling, but in my 737NG book there is nothing stating that the Autobrake Disarm Light should flash in the circumstances you describe. It lights as follows:

1. Momenrtarily during self-test when RTO selected on the ground.

2. A malfunction exists

3. The system is disarmed BY manual braking during RTO or landing

4. The system is disarmed by moving the speed brake lever from up to down during RTO or landing

5. A/Bs have been selected off because of pressure over 1000 psi

6. Landing was made with RTO selected -- no braking occurs!

In other words, the light is a result of something, not an instruction for you to disarm it -- that happens automatically then you get 3 or in other error conditions. Apart from the test case (1), the light means autobraking is already off or inoperative!.

Regards,

Pete

[jan737]

Thanks Pete, Now it's clear.

And thank you for the further info.

Best regards

Jan Geurtsen