No Black Box In Air Ambulance That Crashed In Jharkhand. What Rules Say

An air ambulance that crashed in Jharkhand's Chatra on Monday, killing all seven people on board, didn't have a black box. Redbird Airways Pvt Ltd's Beechcraft C90 aircraft, VT-AJV, was en route from Ranchi to Delhi when it crashed moments after takeoff. There were five people of a family and two crew members onboard.

According to civil aviation rules, it is not mandatory for the planes that weigh below 5,700 kilograms to have cockpit voice recorders (CVR) or flight data recorders (FDR), as the black boxes are formally known.

The maximum takeoff weight of the crashed aircraft was 4,583 kg, which is why the CVR and the FDR were not installed.

Why Black Boxes Are Helpful In Plane Crash Probes

The CVR records the flight crew's voices and other sounds inside the cockpit, while the FDR records many different operating conditions of the flight.

The CVR also records communications with air traffic control, automated radio weather briefings, and conversations between the pilots and ground or cabin crew, which are also recorded. The CVR data helps determine the details of crew actions in their conduct of flight before the crash.

The FDR data is used to check deviation in aircraft flight parametres beyond acceptable limits.

Both the CVR and the FDR have proven to be valuable tools in the accident investigation process in the past.

What Rules Say

As per rules, the CVR is to be installed for "all turbine-engined aeroplanes with a seating configuration of more than five passenger seats and a maximum certificated take-off mass of 5,700 kg."

All planes of a maximum certificated take-off mass of over 5,700 kg, for which the individual certificate of airworthiness is first issued on or after January 1, 1987, should also be equipped with a CVR.

The FDRs have to be installed for all "multi-engined turbine-powered aeroplanes of a maximum certificated take-off mass of 5700 kg or less for which the individual certificate of airworthiness is first issued on or after January 1, 1990."

The first Certificate of Airworthiness (C of A) for the crashed aircraft was issued in 1987, which is prior to January 1, 2016 (applicability date for the CVR requirements) and prior to January 1, 1990 (applicability date for the FDR requirements).

How Will Probe Move Forward

As per sources, investigators are examining air traffic control communications, wreckage analysis, and eyewitness accounts to reconstruct the sequence of events leading to the accident.

Among the key lines of inquiry is whether a malfunctioning onboard weather radar caused the Beechcraft C90 King Air to deviate from its planned flight path.