@PARIKRAMA what on earth make these analysts/surveyors/quality checkers believe that such thing wouldn't happen to the aircraft on the sea. I mean, the people taking decisions should know in first place that etc plane is going to transport many precious lives that cannot be replaced so the signal/beeper/location gadget must be installed in the way whether the pieces floats or the whole plane goes down/underwater. There is no 100% calculation in-case of a plane would touch the water and wouldn't sink and a,b,c and x,y,z parts of particular area of the A/c would float. Also, in my opinion, a very basic and needed upgrade was not done which proves great negligence at the part of approving authority which should be grilled for the loss of these lives. On other hand, if the A/C was not installed with such crucial part, shouldn't be allowed/cleared to fly over such long water line that too during such kind of bad weather.
However, the damage cannot be reversed but taking such necessary measures can save many others though grilling of negligent ones could send message for many others as well that why to wake-up after the loss. Heard that these planes were upgraded in India and while looking at the detail, failed to find any part that works underwater as signal, was not installed. So also, the tracking system was missing which is another aspect that missing AN-32 cannot be located.
Such common upgrade shouldn't be ignored and needed well in-time that in-case of any such incident, the recovered parts and data will help to avoid any scene in future so also will help to rectify the technical failure that brought the plane down.
The change or need of new plane can only be justified while the one has many of details proving the failure of current plane within definition of technical flaws and is risky etc. In my opinion, such evaluation can only be done with available data yet that is missing here as whether it was the plane failure or human error or how may other plane can survive in etc conditions.