MH17 crash: What are the 'black boxes' and what could they reveal?

The black boxes of the Malaysia Airlines flight will be analysed by Britain's Air Accidents Investigation Branch

Britain's Air Accidents Investigation Branch (AAIB) has been tasked with retrieving crucial data from the black boxes of the Malaysia Airlines flight MH17 to be sent for "international analysis", in an effort to determine the circumstances surrounding the plane crash in eastern Ukraine.

On Tuesday, pro-Russian rebels in the area handed over the two recorders found in the wreckage of the plane crash, which killed all 298 passengers on board.

But what are the 'black boxes' and what information could they actually provide the investigation with?

Commercial and corporate aircraft's must be fitted with a flight data recorder (FDR) and cockpit voice recorder (CVR). They store key flight parameters, conversations that took place and any sounds from inside the cockpit.

Both are designed to withstand a severe aircraft accident so their data can be used to investigate the circumstances of aviation incidents. They are usually installed in the tail of the plane to increase their chance of survival in a crash.

Despite their names, the recorders are a bright orange colour in order to make them easier to discover. They are also fitted with an underwater locater beacon which is activated when water comes into contact with a sensor.

The Flight Data Recorder

The FDR’s main purpose is to record the various operating functions of a plane, including altitude, engine power, the direction a plane is travelling in, time, airspeed, and hundreds of other actions.

They can also monitor other flight parameters, such as auto-pilot and fuel gage.

So, whenever a pilot flicks a switch or presses a button, these actions are recorded. A FDR can record between 17 and 25 hours of flight data using solid-state memory boards.

The flight recorder recovered from flight Air France 447 (AFP/Getty) The flight recorder recovered from flight Air France 447 (AFP/Getty) It also records warnings, such as the loss of cabin pressure, depending on how quickly power is lost as both the FDRs and CVRs are powered by generators drawing from the plane’s engines.

The data taken from a FDR can be used to reconstruct the flight itself prior to a crash, to gain a better understanding of how the plane was being handled shortly before the an incident.

The Cockpit Voice Recorder

The CVR records conversations between crew and radio communications between the cockpit and other personnel, such as ground control or other planes.

It works by recording the signals of microphones and earphones attached to the pilot and co-pilot’s headsets, headset of a third crew member (if there is one on board) and an area microphone in the roof of the cockpit.

The flight recorders from Continental Airlines flight 1404 are shown at the National Transportation Safety Board headquarters December 22, 2008 in Washington, DC (Getty) The flight recorders from Continental Airlines flight 1404 are shown at the National Transportation Safety Board headquarters December 22, 2008 in Washington, DC (Getty) They record ambient sounds that occur within the cockpit, such as engine noises, which investigators can also analyse when trying to determine the cause of the crash.

The microphones send audio to the CVR, where the sounds are stored.

Audio data is recorded for a minimum of two hours and is important for an aviation investigation, particularly for establishing the timing of events in a crash.

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksA special investigation by Andy McSmith
Life and Style
Powdered colors are displayed for sale at a market ahead of the Holi festival in Bhopal, India
techHere's what you need to know about the riotous occasion
Arts and Entertainment
Larry David and Rosie Perez in ‘Fish in the Dark’
theatreReview: Had Fish in the Dark been penned by a civilian it would have barely got a reading, let alone £10m advance sales
News
Details of the self-cleaning coating were published last night in the journal Science
science
News
Approved Food sell products past their sell-by dates at discounted prices
i100
News
Life-changing: Simone de Beauvoir in 1947, two years before she wrote 'The Second Sex', credited as the starting point of second wave feminism
peopleHer seminal feminist polemic, The Second Sex, has been published in short-form to mark International Women's Day
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Finance Assistant / Credit Controller

£16000 - £18000 per annum: Recruitment Genius: They are an award-winning digit...

Ashdown Group: Senior VMware Platform Engineer - VMware / SAN / Tier3 DC

£45000 - £55000 per annum + benefits: Ashdown Group: Senior VMware Platform En...

Recruitment Genius: Purchasing Assistant

£10000 - £16000 per annum: Recruitment Genius: A distributor of specialist ele...

Recruitment Genius: Sales Ledger Assistant

£17000 - £19000 per annum: Recruitment Genius: A distributor of specialist ele...

Day In a Page

Homeless Veterans campaign: Donations hit record-breaking £1m target after £300,000 gift from Lloyds Bank

Homeless Veterans campaign

Donations hit record-breaking £1m target after huge gift from Lloyds Bank
Flight MH370 a year on: Lost without a trace – but the search goes on

Lost without a trace

But, a year on, the search continues for Flight MH370
Germany's spymasters left red-faced after thieves break into brand new secret service HQ and steal taps

Germany's spy HQ springs a leak

Thieves break into new €1.5bn complex... to steal taps
International Women's Day 2015: Celebrating the whirlwind wit of Simone de Beauvoir

Whirlwind wit of Simone de Beauvoir

Simone de Beauvoir's seminal feminist polemic, 'The Second Sex', has been published in short-form for International Women's Day
Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

Mark Zuckerberg’s hiring policy might suit him – but it wouldn’t work for me

Why would I want to employ someone I’d be happy to have as my boss, asks Simon Kelner
Confessions of a planespotter: With three Britons under arrest in the UAE, the perils have never been more apparent

Confessions of a planespotter

With three Britons under arrest in the UAE, the perils have never been more apparent. Sam Masters explains the appeal
Russia's gulag museum 'makes no mention' of Stalin's atrocities

Russia's gulag museum

Ministry of Culture-run site 'makes no mention' of Stalin's atrocities
The big fresh food con: Alarming truth behind the chocolate muffin that won't decay

The big fresh food con

Joanna Blythman reveals the alarming truth behind the chocolate muffin that won't decay
Virginia Ironside was my landlady: What is it like to live with an agony aunt on call 24/7?

Virginia Ironside was my landlady

Tim Willis reveals what it's like to live with an agony aunt on call 24/7
Paris Fashion Week 2015: The wit and wisdom of Manish Arora's exercise in high camp

Paris Fashion Week 2015

The wit and wisdom of Manish Arora's exercise in high camp
8 best workout DVDs

8 best workout DVDs

If your 'New Year new you' regime hasn’t lasted beyond February, why not try working out from home?
Paul Scholes column: I don't believe Jonny Evans was spitting at Papiss Cissé. It was a reflex. But what the Newcastle striker did next was horrible

Paul Scholes column

I don't believe Evans was spitting at Cissé. It was a reflex. But what the Newcastle striker did next was horrible
Miguel Layun interview: From the Azteca to Vicarage Road with a million followers

From the Azteca to Vicarage Road with a million followers

Miguel Layun is a star in Mexico where he was criticised for leaving to join Watford. But he says he sees the bigger picture
Frank Warren column: Amir Khan ready to meet winner of Floyd Mayweather v Manny Pacquiao

Khan ready to meet winner of Mayweather v Pacquiao

The Bolton fighter is unlikely to take on Kell Brook with two superstar opponents on the horizon, says Frank Warren
War with Isis: Iraq's government fights to win back Tikrit from militants - but then what?

Baghdad fights to win back Tikrit from Isis – but then what?

Patrick Cockburn reports from Kirkuk on a conflict which sectarianism has made intractable