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Guest dcampbe

Autobrake

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My autobrake is not working. RTO setting on takeoff or 1,2,3 and max on landing.Thank YouDonKMCC

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>My autobrake is not working. RTO setting on takeoff or 1,2,3>and max on landing.>>Thank You>>Don>KMCCautobrakes are disarmed when the throttle isn't at idle. Your problem can be caused by a miscalibrated joystick or if you haven't manually pulled the throttle back to idle.For RTO, your autothrottle must be out of TOGA mode and throttle pulled back to idle for the autobrakes to engage. You can cancel TOGA by right clicking on the TOGA screw.Try testing without any external joysticks and see if the problem goes away - remember to set the throttle to idle by hitting F1.

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Timothy MetzingerI did not know the autothrottle must be out of TOGA mode. That fixed the problem.ThanksDonKMCC

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"For RTO, your autothrottle must be out of TOGA mode and throttle pulled back to idle for the autobrakes to engage. You can cancel TOGA by right clicking on the TOGA screw."So you can't override the (imaginary) autothrottle servo in PMDG with manual joystick throttle input (during RTO), even in thrust hold mode, Tim? (Can't say I've tried it)Is it standard (real world) procedure to hit one of the A/T disconnect switches as you pull back on the throttles during RTO? (above 80kts) Or is it pointless, because THR HLD mode has already removed power from the servomotors?).Thanks.Cheers.Ian.

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>So you can't override the (imaginary) autothrottle servo in>PMDG with manual joystick throttle input (during RTO), even in>thrust hold mode, Tim? (Can't say I've tried it)In the sim, that's correct. What I've done is assigned two separate controller buttons for TOGA-activate and TOGA-deactivate, and am ready to disconnect TOGA until V1.In the real airplane, I imagine that overriding the throttles triggers cancellation of TOGA, but one of our real-world NG drivers will probably chime in.

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Nope, there's no way to cancel TOGA! Except of course, disconnecting any autopilots and the autothrottle and manually flying the plane, switching off the flight directors.

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>Nope, there's no way to cancel TOGA! Except of course,>disconnecting any autopilots and the autothrottle and manually>flying the plane, switching off the flight directors.Iz,I think the question is, if you reject the takeoff at 95 KIAS, do you just yank back the throttles?Or do you have to push any buttons to disconnect the autothrottles and activate the autobrakes?

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Hello all,To reject a take-off at 95 kts (above 90 kts), with the autobrake system RTO mode armed previously, it is necessary to retard the forward thrust levers to idle: thus maximum braking is applied automatically. Additionally, if A/T is engaged, the pilot must disengage the A/T manually after closing the thrust levers.Greetings, and a happy New Year to everyone,Zoltan HegedusBudapest, HungaryEDIT: forgot half of the info.. sorry :)

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"Additionally, if A/T is engaged, the pilot must disengage the A/T manually after closing the thrust levers."So this is necessary even if the A/T is in THR HLD mode (above 80kts), Zoltan? (Or is it just procedure?)I'm also wondering if activating the Reversers also deactivates/inhibits the A/T (as, I recall, it does on the 767)?Thanks.Cheers.Ian.

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Hi"So this is necessary even if the A/T is in THR HLD mode (above 80kts), Zoltan? (Or is it just procedure?)"As far as I know it is necessary in all cases when A/T is engaged. Also note, that below 90 kts, RTO autobraking will NOT be applied, and the disarm light will also not illuminate."I'm also wondering if activating the Reversers also deactivates/inhibits the A/T"If I recall correctly, it is necessary to manually disconnect the A/T in all cases: reverse thrust must/should be applied as necessary during a rejected takeoff procedure after the speedbrake lever position has been verified.Hope that helps.Regards,Zoltan Hegedus

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"As far as I know it is necessary in all cases when A/T is engaged."Thanks, Zoltan.We may have to define "engaged", though... as in THR HLD, the A/T servomotors are depowered ;-) "reverse thrust must/should be applied as necessary during a rejected takeoff procedure after the speedbrake lever position has been verified."Interesting. So the speedbrake lever is manually deployed before the reversers during RTO? I thought it would have been better to observe the lever position after reverser deployment, as reverser deployment automatically activates the speedbrake lever?Thanks.Cheers.Ian.

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Hello again,Let me try to clarify the procedure again a bit more thoroughly, according to what I know.Assuming we are above 90 kts, with RTO autobraking selected (and optionally A/T engaged, as in switched ON):1) Close thrust levers (switch the A/T to OFF if required)2) Verify the RTO autobraking, and monitor the decelaration: apply manual wheel brakes if necessary3) Set speed brakes to UP position by moving the lever4) Apply maximum reverse thrust as requiredAnd finally bring the aircraft to a complete stop: when the plane has come to a stop, it is necessary to review the brake cooling schedule for information about required brake cooling times and precautions.That's a short wrap up of the actions you - the captain :) - must accomplish during a RTO, according to the procedure I know. Some of the items may or may not apply in certain situations, but following this procedure will guarantee nothing is skipped that could be potentially dangerous."Interesting. So the speedbrake lever is manually deployed before the reversers during RTO? I thought it would have been better to observe the lever position after reverser deployment, as reverser deployment automatically activates the speedbrake lever?"As far as I know, the standard procedure is to first deploy speedbrakes manually, then apply reverse thrust: you are correct because it is possible to simply deploy the thrust reversers, which under certain circumstances will activate the automatic speedbrake system. The conditions are I believe:- main gear wheel speed at or above 60 kts- both thrust levers at idle- reverse thrust levers activatedTherefore it's possible to simply apply reverse thrust, and then verify the speedbrake lever position :)Kind regards,Zoltan Hegedus

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Thanks, Zoltan.BTW, are you a real world 737 pilot? I notice that you use the expression "as far as I know" in your explanation, so I'm guessing that you may not be (or, perhaps, are in training).I often use a similar expression because I have had no formal maintenance engineer training on the 737NG. Manuals alone, quite often, only give you a basic understanding of airplane systems/procedures.Cheers.Ian.

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Ian,Quite right; I am not a real 737 pilot currently. That doesn't mean I won't be one.. or so I hope :) I am currently working for MALEV Hungarian Airlines, but not as a pilot.Greetings,Zoltan Hegedus

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