Aircraft DFDR
Thread Starter
Joined: Mar 2017
Posts: 43
Likes: 0
From: australia
Aircraft DFDR
Hi all..
Any kind soul can explain..the aircraft Digital Flt Data Recorder (DFDR) as I understand has a recording capacity of around 25hrs.
Question..
1. When does it reset to zero hrs? After each flight? Or it continues until its data has reached 25 hrs and then its resetted automatically?
2. If it resets after 25hrs, past data all gone?
Any kind soul can explain..the aircraft Digital Flt Data Recorder (DFDR) as I understand has a recording capacity of around 25hrs.
Question..
1. When does it reset to zero hrs? After each flight? Or it continues until its data has reached 25 hrs and then its resetted automatically?
2. If it resets after 25hrs, past data all gone?

Joined: Jan 2008
Posts: 17,731
Likes: 2,105
From: Reading, UK
If by "reset" you mean deleting all the data, that's not how they usually work.
A 25-hour FDR will normally store the last 25 hours of flight, across however many sectors occupied that duration.
A 25-hour FDR will normally store the last 25 hours of flight, across however many sectors occupied that duration.



Joined: Jul 2013
Aviation Qualifications: Non-Aircrew
Posts: 5,682
Likes: 3,347
From: Everett, WA
DR is correct - that also applies to Voice Recorders (although the storage period is normally shorter).
BTW, 25 hours for the DFDR is the current minimum, many of the new ones go longer. Quick Access Recorders (QAR) can also record for a very long period (although they are not 'crash proof' they are often very valuable for incident investigation since they record stuff not typically on the DFDR).
BTW, 25 hours for the DFDR is the current minimum, many of the new ones go longer. Quick Access Recorders (QAR) can also record for a very long period (although they are not 'crash proof' they are often very valuable for incident investigation since they record stuff not typically on the DFDR).





