FLIGHT RECORDERS - ACCIDENT RECORDER
Everyone has heard of "black boxes" (which are actually orange today for ease of recovery in the event of an accident), but what are they, what are they for and how that works.
A fright of history:
It all started in 1936, with François Hussenot, test engineer at the CEV * in Bordeaux-Mérignac, who carried out the first tests of a flight recorder on a roll of photo paper.
In 1947, François Hussenot created in Massy (France) with his partner Marcel Ramolfo the Société de Fabrication d'Instruments de Mesure, SFIM, which would build the first photographic flight recorders. They will be industrialized and exported to many countries under the reference “type HB”. These flight recorders were first called “hussenographs” before being called FDRs much later.
We are fortunate to have in our museum this example of the Type A-20 SFIM recorder, with the serial number 1875.
And as usual a short presentation:
The recorder is mounted in this support fixed in an aircraft; it can be easily disassembled to be opened in a laboratory and after development of the photo paper, to exploit the data.
The set looks like an old camera body or a movie camera.
Once opened you can see:
The two reels and the photo paper.
In the centre is the recording head where eight infrared bulbs are placed which illuminate the photo paper, the electrical impulses received from the sensors which are transformed into light rays and an image on paper.
Alongside François Hussenot's photographic recorder, which dates from the 1950s, in the museum's window you can also see a much more modern recorder, a cockpit conversation recorder commonly called CVR or (Cockpit Voice Recorder).
The same type of voice recorder was installed on the SA whose production date dates from March 1973 and uses the ARINC 557 standard relating to on-board voice recorders.
Now just a bit of technique…
Data logger:
The flight data recording system accepts several forms of analog and digital information and converts this information to digital format for recording in a flight data recorder. The installation is able to meet all the requirements of the ARINC ** specification.
The main equipment’s are:
- A flight data acquisition unit (FDAU),
- A flight data entry panel (FDEP),
- A digital flight data recorder (DFDR) and
- An underwater locator beacon.
Four potentiometers and an accelerometer are specifically equipped to provide signals corresponding to flight control positions and accelerations in all three axes.
All other input signals are provided by the FDEP and by switches or signal jacks which are an integral part of the systems incorporated into the systems to provide signals to the flight recorder. The FDEP processes the flight documentary data, in digital form for direct entry into the recording system. The FDAU packages the analog information, converts it to digital form, and processes the result, along with the FDEP output, to produce the input signals to the recorder.
Voice recorder:
Is together a sensor (microphone) and a recorder (tape recorder) or a tape recorder in a shell protected from shocks or flames.
Finally, now let's talk a bit about Concorde and the SA:
In addition to two recorders mentioned above:
- The FDR flight parameters recorder (Flight Data Recorder)
- The CVR Cockpit Voice Recorder
Prototypes and pre-productions were additionally equipped with an “Ejection Crash Recorder”. Certainly for questions of identification and research (to know the reasons as quickly as possible).
This image shows the crash recorder in the 01 preproduction aircraft at Duxford.
In the SA, all traces of this equipment in the rear emergency exit have disappeared following the fitting out by Air France for ADP guided tours in 1976.
The only visible sign remains outside on the emergency exit at the rear of the fuselage. The inscriptions still showing the position of the ejector and the announcement of a potential danger during operation.
This article was in its gestation phase when the article appeared on the site of our friend François, which completes ours below, so do not hesitate to consult it without moderation:
Concorde was once again ahead of its time, since today we are once again talking about eject able parameter recorders…
- * CEV (Centre des essais en vol). French Flight test Centre.
- ** ARINC standard defined by the AEEC (Airlines Electronic Engineering Committee) relating to internal aircraft buses and networks and protocols used in aeronautics.
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