Explainer-How black packing containers protect important clues to air disasters

By Tim Hepher

(Reuters) – Flight information and cockpit voice recorders on the Jeju Air jet that crashed on Dec. 29, killing 179 individuals, stopped recording about 4 minutes earlier than it crashed, South Korea’s transport ministry mentioned on Saturday.

Listed here are some particulars on black packing containers and strikes to enhance them.

WHAT ARE BLACK BOXES?

They aren’t really black however high-visibility orange. Specialists disagree how the nickname originated nevertheless it has grow to be synonymous with the hunt for solutions when planes crash.

Many historians attribute their invention to Australian scientist David Warren within the Nineteen Fifties. They’ve developed from early units utilizing wire, foil or magnetic tape to digital chips inside brilliant metallic casings.

They’re necessary and the purpose is to protect clues from cockpit sounds and information to assist forestall future accidents, however to not decide any civil or felony legal responsibility.

There are two recorders: a Cockpit Voice Recorder (CVR) for pilot voices or cockpit sounds and a separate Flight Information Recorder (FDR).

In broad phrases, investigators say the FDR helps them analyse what occurred and the CVR can – however not at all times – begin to clarify why. However specialists warning that no two probes are the identical and nearly all accidents contain a number of elements.

HOW BIG ARE THEY?

They weigh about 10 kilos (4.5 kilos) and comprise 4 predominant elements: 

* a chassis or interface designed to repair the system and facilitate recording and playback

* an underwater locator beacon 

* the core housing or ‘Crash Survivable Reminiscence Unit’ fabricated from stainless-steel or titanium and in a position to face up to forces equal to three,400 occasions the sensation of gravity

* this housing incorporates the recording media which these days are finger-nail sized chips on circuit boards.

HOW ARE RECORDERS HANDLED?

Technicians peel away protecting materials and thoroughly clear connections to ensure they don’t by accident erase information. The audio or information file should be downloaded and copied.

The information should be decoded from uncooked recordsdata earlier than being became graphs.

HOW MUCH INFORMATION IS AVAILABLE?

The capability of flight recorders has been debated for years as authorities weigh enhancements towards the associated fee and the chance of inadvertently creating different issues, reminiscent of drawing energy from different methods wanted in an emergency. Cockpit monitoring has additionally been a delicate subject with pilot unions.

FDRs should file a minimum of 88 important parameters however fashionable methods can sometimes observe 1,000 or extra extra alerts.

The CVR normally incorporates two hours of recordings on a loop however that is being prolonged to 25 hours.

Implementing such regulatory modifications can take years. 

A spate of accidents wherein recorders stopped working when onboard electrical energy was misplaced, together with an Egyptair flight from New York to Cairo in 1999, led the U.S. Nationwide Transportation Security Board to advocate sufficient backup energy to offer 10 minutes of additional recording.

The Federal Aviation Administration proposed the change in 2005 and it was adopted for brand spanking new planes delivered from 2010, eight months after the 737-800 concerned within the Jeju crash left the Boeing (NYSE:BA) manufacturing unit, in keeping with information from FlightRadar24.

Strain to elongate the loop of voice information to 25 hours to mirror trans-oceanic flights started with French suggestions following the crash of Air France 447 in 2009, and accelerated after the disappearance of Malaysia’s MH370 in 2014.

Final yr, the U.S. Federal Aviation Administration Reauthorization Act included the 25-hour requirement for cockpit voice recorders, echoing earlier choices in Europe.