Folks need to understand few things
One thing is The Emergency Locator Transmitter , if that is ON then all aerial assets/Surface assets can use the ping if its within the said range of receiving the Emergency Ping to locate the debris or crashed aircraft.
In this case since the deployment happened in a quick time for SAR OPS and yet no debris has been found till date, it looks fair to conclude that EMERGENCY LOCATOR TRANSMITTER failed to do the job due to unknown circumstances as of now.
Second thing is the Underwater Locator Beacon which runs in Lithium batteries fitted to flight recorders or BLACK BOX. This starts pinging when it detects water immersion and has a range of 2 kms to sometimes 3~3.5km in very favourable conditions. Now this ULB is what is being focused on to detect the debris location. The ping is so minute that aerial assets cannot detect such pings and surface vessels can detect it if and only if wreckage is more like less than 2 km depth.
The area under consideration has a depth of more like 3.2 km implying we are not having an ability to utilise surface ships to detect pings of ULB unless again its extra favorable conditions (weather and lady luck by our side).
Thus in such a situation a Remotely Operated Vehicle (ROV) and a Multi functional support Vehicle or MSV has to be used to check on Sea floors to see if we can detect that faint ping and locate the debris.
But there are limitation and challenges
- battery is normally for max 30 days
- there had been instances in different parts of the world when battery has been leaking and at times of actual crash battery is dead so we get NO ULB ping as well.
I hope now i am clear why P8Is to different aerial assets to surface ship has not been able to find An32 as of now.
The US satellite data check is for detecting the Emergency Locator transmitter ping not Underwater locator beacon/ping. Indian government wishes to check on record the ELT ping to help narrow down to ULB. But there is a high probability ELT search will yield no result and we will focus on ULB soon and get private operators help on this.
@Joe Shearer @MilSpec @Vergennes @Taygibay @AUSTERLITZ @SpArK @Penguin @nair @Abingdonboy @anant_s @WAJsal