Good evening,
I wonder if this is an airline option or type specific. So this is a question for all pilots and engineers of any aircraft type, be it Boeing, Airbus etc.
During preflight, when all automation is disengaged, do you push the autopilot disconnect switch on the yoke for an alert test? If so, will a continuous sound loop start or just a short sound? If a test alert occurs, do you need to reset it by a second push?
Is there a similar test for the autothrottle disconnect switches on the thrust levers?
Thank you!
Regards,
|-|ardy
Hardy,
We (crew) do not perform such tests. I will try it tonight and get back to you.
Best regards,
Mariano
Also, are there associated messages?
I recall the A/T has no sound, but a message, but my memory is fading. I don't know if it depends on how long the button is pushed (to generate the A/T message).
Never did it on the -400, but on the classic we'd get the wailer when we disconnected on the preflight.
[EDIT]
QuoteDuring preflight, when all automation is disengaged, do you push the autopilot disconnect switch on the yoke for an alert test?
I misread your question. If the A/P was already off, I'm pretty sure you wouldn't get any wailer if you hit the yoke disconnect.
Hardy,
Below, please find three very short videos.
Video 1 shows what happened when I pressed and quickly released the yoke A/P Disconnect button. I only got a blink of the amber A/P DISC discrete light, and the wailer.
https://www.dropbox.com/s/hsx2hl90x836qul/Video%20Jun%2021%2C%2003%2000%2029.mov?dl=0
Video 2 shows what happened when I held the yoke A/P Disconnect button pressed. Amber A/P DISC discrete light, Master Warning, EICAS AUTOPILOT DISC Warning message, and wailer activated (for as long as button was held in).
https://www.dropbox.com/s/kcbzesqj1dwyfnr/Video%20Jun%2021%2C%2003%2000%2034.mov?dl=0
Video 3 shows what happened when I pressed and released and then pressed and held the thrust lever A/T Disconnect button. Only the amber A/T DISC discrete light illuminated.
https://www.dropbox.com/s/90sszzm95ckyjgh/Video%20Jun%2021%2C%2003%2000%2044.mov?dl=0
I assume the difference in system response between the first and second videos was caused by me not holding the A/P Disconnect button long enough to allow time for all visual and aural warnings to activate.
I asked the engineer and he said that those tests are not part of his daily or transit (line) checks.
Best regards,
Mariano
Thank you, Mariano.
I think the 744 will behave similarly; it will just trigger EICAS messages (and associated lights and sounds) instead of the 767 specific system lights.
Regards,
|-|ardy
QuoteVideo 3 shows what happened when I pressed and released and then pressed and held the thrust lever A/T Disconnect button. Only the amber A/T DISC discrete light illuminated.
Strange. I still have the recollection that the A/T EICAS msg appeared after some delay. Was your A/T switch armed?
Thanks, Mariano. I would have never thought you could get the wailer just by pushing the yoke disconnect without the A/P being engaged.
Jon
John,
I thought likewise, but the EICAS message never triggered. We do not disarm the A/T unless an abnormal procedure dictates so, which I think is different from the 744.
I will try holding the switch in a bit longer today, just to make sure.
Best regards,
Mariano
Quote from: Hardy Heinlin on Fri, 21 Jun 2019 14:52
I think the 744 will behave similarly; it will just trigger EICAS messages (and associated lights and sounds) instead of the 767 specific system lights.
Regards,
|-|ardy
Exactly so, checked a few nights ago.
Regards,
Mark.
The same pin on the B767 A/T computer outputs to the annunciator light and to the EICAS Computer. The logic in the EICAS computer only shows a 1 second delay on the message.
Quote from: mark744 on Sun, 23 Jun 2019 10:44
Quote from: Hardy Heinlin on Fri, 21 Jun 2019 14:52
I think the 744 will behave similarly; it will just trigger EICAS messages (and associated lights and sounds) instead of the 767 specific system lights.
Regards,
|-|ardy
Exactly so, checked a few nights ago.
Regards,
Mark.
So you did or didn't get an
A/T message on EICAS, Mark, with a long switch push?
I did get a continuous message and aural, as long as the button was pressed.
Regards,
Mark
Quote from: mark744 on Wed, 26 Jun 2019 22:39
I did get a continuous message and aural, as long as the button was pressed.
Regards,
Mark
A/T aural? Was this after engine start?
After engine shutdown
Quote from: John H Watson on Thu, 27 Jun 2019 02:02
A/T aural? Was this after engine start?
Mark is probably talking about the autopilot wailer?
Sorry, yes
So, in summary:
744: A/P and A/T messages on EICAS
767: (EDIT: Only A/P message on EICAS, but both A/P and A/T on the discrete warning indicators on the main instru. panel
Weird.
See messages below.)
Just held (767) A/T Disconnect switch again for ten seconds on the ground with engines shutdown and only EICAS message (and discrete light) activated. No wailer.
Best regards,
Mariano
Thanks for checking again, Mariano.
Earlier you said
QuoteVideo 3 shows what happened when I pressed and released and then pressed and held the thrust lever A/T Disconnect button. Only the amber A/T DISC discrete light illuminated.
Hence my confusion.
John,
Indeed, you are right. I just checked the video and the EICAS message did not display. This time it did (different ship) but I kept it pressed longer, so I assume that I didn't give it enough time on the initial video.
Good catch.
I will try it one more time tomorrow on yet another ship, as a sort of a tie breaker.
Best regards,
Mariano
I can't tell if your video is long enough to record the 1 second delay that the EICAS logic has.
Also, maybe the second push reset the timer?
Yes, I now believe the timer might have been rest, as you said.
Best regards,
Mariano
Tried a third ship today. A/T Disconnect on the ground with engines shutdown only triggered EICAS message, discrete (767) light and no wailer.
Best regards,
Mariano
On the 744 when the engines are shutdown, caution messages are enabled to appear but they won't activate the caution light & beeper.
The logic on the 767 is probably similar.
So, when the engines are shutdown, I assume the A/T disco test on the 744 will only trigger the caution message, but no caution light & beeper.
|-|ardy
Quote from: Hardy Heinlin on Sat, 29 Jun 2019 13:23
So, when the engines are shutdown, I assume the A/T disco test on the 744 will only trigger the caution message, but no caution light & beeper.
|-|ardy
Exactly so.
Regards,
Mark
Fine, fine.
I will implement this logic in PSX 10.82.
Thanks,
|-|ardy
A/P and A/T disconnect alert tests are now possible in PSX 10.82:
http://aerowinx.com/board/index.php?topic=4191.0
Regards,
|-|ardy
Thanks, Hardy!
C|-|eeЯs