The black box of the ill-fated AN 32 aircraft which crashed in Arunachal Pradesh killing all 13 personnel on board was found to have suffered damage in the accident, reported news agency ANI.
The black box contains the cockpit voice recorder (CVR) and flight data recorder (FDR). The damage to them may lead to delays in knowing the exact cause of the crash, said reports quoting sources in Air Force.
“The blackbox was recovered and brought out of the crash site almost three days ago. It has been damaged in the crash and we are analysing whether the data from it can be retrieved by the HAL or it will have to be sent to some other agency,” defence sources told ANI.
It is rare for black boxes to suffer damage, though there are instances when it was reported to have happened. Black boxes are designed to protect their brains — the memory boards that hold the data. They are encased in aluminium which is covered by an inch-thick layer of insulation that can withstand high temperatures. This is encased in an outer cover of titanium or stainless steel. That whole package, known as the crash survivable memory unit, is subjected to rigorous testing.
Because it must be able to survive a violent and fiery plane crash, it is designed to withstand crash impacts of 3,400Gs (or 3,400 times the force of gravity), as well as an hour in an 1,100-degree Celsius inferno. They’re engineered to endure 30 days in salt water, a soaking in jet fuel, and five minutes under 5,000 pounds per square inch of force. And finally, manufacturers load a steel pin with a 500-pound weight behind it ten feet above the box, then drop it to test the resiliency of the metal casing. The rest of the black box — including the power supply and circuit boards — doesn’t have the same protections and may well be destroyed in a crash.
The sources said that prima facie it seemed that the accident happened due to navigational error but the exact causes would be known only after a detailed probe is carried out into the incident.
The Russian-origin AN-32 aircraft went missing on June 3 after taking off from Assam’s Jorhat. It was headed towards Mechuka Advanced Landing Ground in Arunachal Pradesh near the border with China when it lost contact with ground authorities at around 1 pm.
After eight days of a massive search operation, the wreckage of the plane was spotted by an IAF chopper at a height of 12,000 feet near Gatte village on the border of Siang and Shi-Yomi districts. All the 13 personnel including seven officers were killed in the incident.