I would like to add a D10 to my D180/HS34 installation. I also have auto pilot servos in the system. The question is how does the system handle a failure of either the D10 or D180, Is it designed so the failed instrument will disconnect from the DSAB so the remaining device will continue operations? Would this include taking over the auto pilot functions?
buss operation with failed instrument
- Thread starter mhubel
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It's not clear if you mean an EMS-D10 or an EFIS-D10A. Ideally, you want to use an EFIS-D10A in this setup. That gets you a backup set of flight instruments. If you connect up and EMS-D10, you can display the D180's flight instruments on the EMS, but if the D180 were to have an issue you wouldn't have any flight instruments remaining. Additionally, the EMS-D10's engine page won't slave to the D180 for technical reasons. When you use the EFIS-D10A, you can display the D180's EMS page on it. So for a variety of reasons, we'd recommend the EFIS-D10A in this case.
To answer your question though: The DSAB master controls the AP as well as the HS34. Nominally that would be your D180. If the DSAB master failes (the D180), you'd still have flight instruments on the EFIS-D10A but no autopilot or connectivity to the HS34. However, if the D10A fails but the DSAB master (D180) is still available, the D180, HS34, and AP all continue working as usual.
To answer your question though: The DSAB master controls the AP as well as the HS34. Nominally that would be your D180. If the DSAB master failes (the D180), you'd still have flight instruments on the EFIS-D10A but no autopilot or connectivity to the HS34. However, if the D10A fails but the DSAB master (D180) is still available, the D180, HS34, and AP all continue working as usual.
Thank you for the answer. Unfortunately, unless the auto pilot function was taken over by the D10A the addition is not really justified. I don't need backup engine monitoring but want an attitude indicator which could take over auto pilot/navigation duty.
Suppose a mechanical switch was used to select either the D180 or the D10A for connection to the DSAB buss. Is there any reason the D10A would not take over the autopilot/HS34 functions when it was switched in?
Suppose a mechanical switch was used to select either the D180 or the D10A for connection to the DSAB buss. Is there any reason the D10A would not take over the autopilot/HS34 functions when it was switched in?
So I suppose your proposed setup could work. If you had the D10A set up to the same servos COMPLETELY INDEPENDENTLY, and then severed the DSAB wires for normal circumstances, and then kept the DSAB wires to the servos severed nominally, (but with the DSAB network configured from the D10A as well), in the event your D180 died, you could flip the switch, the D10A *should* find the servos, but then you need to re-engage the autopilot again. Under no circumstance will it automatically take over.
In a no-switch version of this, you would DSAB everything together from the D180, configure and test the AP, then do the same thing from the D10A and configure and test the AP, and then finally, reconfigure the DSAB network so that the D180 is master. That would let you, in the event of a D180 failure, do a quick manual DSAB reconfiguration in flight, and then fly the AP from the D10A after then re-engaging it.
Neither of these are officially-supported scenarios though. We wouldn't recommend relying on an in-flight DSAB reconfiguration in an emergency configuration, and even having the switched configuration depends on having the system configured PERFECTLY beforehand. If it were my airplane, the second EFIS would be there as a full set of backup flight instruments in an emergency. If it were the AP-controlling EFIS that failed, you wouldn't have the AP on the remaining one, but you'd still have every primary flight instrument to get yourself home on a "complete" partial panel.
In a no-switch version of this, you would DSAB everything together from the D180, configure and test the AP, then do the same thing from the D10A and configure and test the AP, and then finally, reconfigure the DSAB network so that the D180 is master. That would let you, in the event of a D180 failure, do a quick manual DSAB reconfiguration in flight, and then fly the AP from the D10A after then re-engaging it.
Neither of these are officially-supported scenarios though. We wouldn't recommend relying on an in-flight DSAB reconfiguration in an emergency configuration, and even having the switched configuration depends on having the system configured PERFECTLY beforehand. If it were my airplane, the second EFIS would be there as a full set of backup flight instruments in an emergency. If it were the AP-controlling EFIS that failed, you wouldn't have the AP on the remaining one, but you'd still have every primary flight instrument to get yourself home on a "complete" partial panel.
Thanks,
It does sound like the switch is the way to go. Effectively it does provide a completely independent backup EFIS and one which fits in my panel (rather important). This also allows a continued AP with minimal in flight effort.
I expect that getting the D10A setup to operate the AP can't be much more difficult than getting the D180 to do it in the first place. Not too bad.
All said and done, I am a bit surprised that the D180/D10A design does not provide some form of master switch over capability in the event of a failure.
It does sound like the switch is the way to go. Effectively it does provide a completely independent backup EFIS and one which fits in my panel (rather important). This also allows a continued AP with minimal in flight effort.
I expect that getting the D10A setup to operate the AP can't be much more difficult than getting the D180 to do it in the first place. Not too bad.
All said and done, I am a bit surprised that the D180/D10A design does not provide some form of master switch over capability in the event of a failure.
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For various technical reasons, incorporating a full "... master switch over capability in the event of a failure" in the FlightDEK-D180 / EFIS-D100 / EFIS-D10A products is, unfortunately, not feasible.
However, lesson learned, and our SkyView system works as you describe. If you equip for redundancy in a SkyView system, and one of the displays fail, there is full failover to the remaining display (s).
However, lesson learned, and our SkyView system works as you describe. If you equip for redundancy in a SkyView system, and one of the displays fail, there is full failover to the remaining display (s).