They do this with all components that they wish to salvage out of drowned aircraft. The very instant that you remove submerged components from the water they start to corrode. It better to keep them in the water until they get to an inspection/repair facility where the can be transferred to a corrosion inhibiting media. After that they can be taken to the workbenches.
If it was recovered from under water, letting it dry out could damage the recording so that they couldn't read it at all.
There are ways to safely recover the recording without damaging it, but it has to be done in a controlled manner.
The precise time of loss of Air France flight AF447 on 1-Jun-200 is unknown. The flight was out of radar range at the time and the flight data/voice recorders have not been recovered.
The Data option
Flight recorders have limitations such as not being able to prevent accidents, limited storage capacity for recording data, and the potential for data to be lost if the recorder is damaged in a crash. Additionally, retrieving flight data from underwater can be challenging and time-consuming.
Examples of black boxes include flight data recorders on airplanes, event data recorders in vehicles, and cryptographic algorithms in digital security systems. In general, a black box refers to a system or device that operates based on inputs and outputs without revealing its internal workings.
No
Yes, data can be recovered from a tape using various software available in the market.
"Black box" everywhere except aviation means a device whose users know what the inputs and outputs are, but not what's happening inside. In aviation, a "black box" (which is really painted orange so it's easy to find in the wreckage) is a recorder. Planes that are required to carry them have two - the cockpit voice recorder and the flight data recorder.
Because the first Flight Data Recorders were conceived in 1953 and the first one was produced in 1957 in Australia, it is assumed that the first one to be installed and field tested was on some Australian aircraft.
As you have recovered data from the failed hard-disk, it would be best to buy a new hard-disk.
Compact flash audio recorders are useful because they record data onto compact flash cards, which come in a variety of sizes for storing a lot or a little data. Those cards can then be inserted into a card reader for retrieving the data stored on them, which is very convenient.
en.wikipedia.org/wiki/Data_recovery has a definition of what data recovery is all about. For the software you can go to getdata.com. They may even have more information as to what can be recovered and what can not be recovered.
Some data can be recovered if the computer is not backed up and crashes. Many programs or software can detect a crash and automatically backs up recent updates or data changes.