EXDAC
2025-06-15T20:56:00
permalink Post: 11902827

Quote:

Originally Posted by DaveReidUK

One of the two recorders on the 787 is equipped with RIPS (Recorder Independent Power Supply), which will give a minimum of 10 minutes' operation in the event of a power supply failure.

But as previously posted a recorder is only as good as the systems that provide the data to it. If those systems, or some of those systems, are not powered the data is simply not available to be recorded. You need the DFDAU (or equivalent) to be powered and you need the systems that feed data to the DFDAU (or equivalent) to be powered and operational.

Edit to add - RIPS will likely maintain CVR function.

1 user liked this post.

DaveReidUK
2025-06-15T21:05:00
permalink Post: 11902840

Quote:

Originally Posted by EXDAC

Correct, on the 787 it's the forward EARF that has the RIPS, and it will continue to record inputs from the CAM.

Innaflap
2025-06-28T14:25:00
permalink Post: 11912515

Quote:

Originally Posted by Sailvi767

I suspect both recorders will contain the same data. Given the radio transmission after the loss of thrust the aircraft still had at least the emergency electrical bus powered. This should have kept both recorders online. It is however possible given the 10 minute battery backup that Boeing chose to put the the recorders on another bus but that\x92s not the norm.

I'm pretty sure that within the 787 data is passed over the serial data protocols to a DFDAU - Digital Flight Data Acquisition Unit where it is stored as a form of database. Quite possibly XML

Any device subscribing to the AU will be getting the same information. This would include the DFDRs and whatever is used for ADS-B

Happy to be corrected

EXDAC
2025-06-28T15:54:00
permalink Post: 11912544

Quote:

Originally Posted by Innaflap

I'm pretty sure that within the 787 data is passed over the serial data protocols to a DFDAU - Digital Flight Data Acquisition Unit where it is stored as a form of database. Quite possibly XML

I am not aware of any requirement for a DFDAU (or equivalent) to store any data. I say "or equivalent" because in B717 the DFDAU is not an LRU. It is a functional partition of the VIA.

It's not clear to me that 787 EAFR even requires an external DFDAU. The GE EAFR does not -

"Provides Flight Data Acquisition function of ARINC 664 p7 data parameters – No need for a Digital Flight Data Acquisition Unit (DFDAU)."

ref https://www.geaerospace.com/sites/de...rder-3254F.pdf

1 user liked this post.

Innaflap
2025-06-30T14:42:00
permalink Post: 11913673

Quote:

Originally Posted by EXDAC

I am not aware of any requirement for a DFDAU (or equivalent) to store any data. I say "or equivalent" because in B717 the DFDAU is not an LRU. It is a functional partition of the VIA.

It's not clear to me that 787 EAFR even requires an external DFDAU. The GE EAFR does not -

"Provides Flight Data Acquisition function of ARINC 664 p7 data parameters \x96 No need for a Digital Flight Data Acquisition Unit (DFDAU)."

ref https://www.geaerospace.com/sites/de...rder-3254F.pdf

In this case, there is still an AU - it's just integrated into the EAFR.

EXDAC 2025-06-15T20:56:00 permalink Post: 11902827	Quote: Originally Posted by DaveReidUK One of the two recorders on the 787 is equipped with RIPS (Recorder Independent Power Supply), which will give a minimum of 10 minutes' operation in the event of a power supply failure. But as previously posted a recorder is only as good as the systems that provide the data to it. If those systems, or some of those systems, are not powered the data is simply not available to be recorded. You need the DFDAU (or equivalent) to be powered and you need the systems that feed data to the DFDAU (or equivalent) to be powered and operational. Edit to add - RIPS will likely maintain CVR function. 1 user liked this post.
DaveReidUK 2025-06-15T21:05:00 permalink Post: 11902840	Quote: Originally Posted by EXDAC But as previously posted a recorder is only as good as the systems that provide the data to it. If those systems, or some of those systems, are not powered the data is simply not available to be recorded. You need the DFDAU (or equivalent) to be powered and you need the systems that feed data to the DFDAU (or equivalent) to be powered and operational. Edit to add - RIPS will likely maintain CVR function. Correct, on the 787 it's the forward EARF that has the RIPS, and it will continue to record inputs from the CAM.
Innaflap 2025-06-28T14:25:00 permalink Post: 11912515	Quote: Originally Posted by Sailvi767 I suspect both recorders will contain the same data. Given the radio transmission after the loss of thrust the aircraft still had at least the emergency electrical bus powered. This should have kept both recorders online. It is however possible given the 10 minute battery backup that Boeing chose to put the the recorders on another bus but that\x92s not the norm. I'm pretty sure that within the 787 data is passed over the serial data protocols to a DFDAU - Digital Flight Data Acquisition Unit where it is stored as a form of database. Quite possibly XML Any device subscribing to the AU will be getting the same information. This would include the DFDRs and whatever is used for ADS-B Happy to be corrected
EXDAC 2025-06-28T15:54:00 permalink Post: 11912544	Quote: Originally Posted by Innaflap I'm pretty sure that within the 787 data is passed over the serial data protocols to a DFDAU - Digital Flight Data Acquisition Unit where it is stored as a form of database. Quite possibly XML I am not aware of any requirement for a DFDAU (or equivalent) to store any data. I say "or equivalent" because in B717 the DFDAU is not an LRU. It is a functional partition of the VIA. It's not clear to me that 787 EAFR even requires an external DFDAU. The GE EAFR does not - "Provides Flight Data Acquisition function of ARINC 664 p7 data parameters – No need for a Digital Flight Data Acquisition Unit (DFDAU)." ref https://www.geaerospace.com/sites/de...rder-3254F.pdf 1 user liked this post.
Innaflap 2025-06-30T14:42:00 permalink Post: 11913673	Quote: Originally Posted by EXDAC I am not aware of any requirement for a DFDAU (or equivalent) to store any data. I say "or equivalent" because in B717 the DFDAU is not an LRU. It is a functional partition of the VIA. It's not clear to me that 787 EAFR even requires an external DFDAU. The GE EAFR does not - "Provides Flight Data Acquisition function of ARINC 664 p7 data parameters \x96 No need for a Digital Flight Data Acquisition Unit (DFDAU)." ref https://www.geaerospace.com/sites/de...rder-3254F.pdf In this case, there is still an AU - it's just integrated into the EAFR.

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