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
Arts and Entertainment
Books should be for everyone, says Els, 8. Publisher Scholastic now agrees
booksAn eight-year-old saw a pirate book was ‘for boys’ and took on the publishers
Life and Style
Mary Beard received abuse after speaking positively on 'Question Time' about immigrant workers: 'When people say ridiculous, untrue and hurtful things, then I think you should call them out'
tech
Life and Style
Most mail-order brides are thought to come from Thailand, the Philippines and Romania
life
News
i100
Life and Style
tech
Voices
Margaret Thatcher, with her director of publicity Sir Gordon Reece, who helped her and the Tory Party to victory in 1979
voicesThe subject is being celebrated by the V&A museum, triggering some happy memories for former PR man DJ Taylor
  • Get to the point
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: Installation and Service / Security Engineer

£22000 - £40000 per annum: Recruitment Genius: This company is part of a Group...

Recruitment Genius: Service Charge Accounts Assistant

£16000 - £18000 per annum: Recruitment Genius: Are you a a young, dynamic pers...

Cancer Research UK: Corporate Partnerships Volunteer Events Coordinator – London

Voluntary: Cancer Research UK: We’re looking for someone to support our award ...

Ashdown Group: Head of IT - Hertfordshire - £90,000

£70000 - £90000 per annum + bonus + car allowance + benefits: Ashdown Group: H...

Day In a Page

General Election 2015: Chuka Umunna on the benefits of immigration, humility – and his leader Ed Miliband

Chuka Umunna: A virus of racism runs through Ukip

The shadow business secretary on the benefits of immigration, humility – and his leader Ed Miliband
Yemen crisis: This exotic war will soon become Europe's problem

Yemen's exotic war will soon affect Europe

Terrorism and boatloads of desperate migrants will be the outcome of the Saudi air campaign, says Patrick Cockburn
Marginal Streets project aims to document voters in the run-up to the General Election

Marginal Streets project documents voters

Independent photographers Joseph Fox and Orlando Gili are uploading two portraits of constituents to their website for each day of the campaign
Game of Thrones: Visit the real-life kingdom of Westeros to see where violent history ends and telly tourism begins

The real-life kingdom of Westeros

Is there something a little uncomfortable about Game of Thrones shooting in Northern Ireland?
How to survive a social-media mauling, by the tough women of Twitter

How to survive a Twitter mauling

Mary Beard, Caroline Criado-Perez, Louise Mensch, Bunny La Roche and Courtney Barrasford reveal how to trounce the trolls
Gallipoli centenary: At dawn, the young remember the young who perished in one of the First World War's bloodiest battles

At dawn, the young remember the young

A century ago, soldiers of the Empire – many no more than boys – spilt on to Gallipoli’s beaches. On this 100th Anzac Day, there are personal, poetic tributes to their sacrifice
Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves

Follow the money as never before

Dissent is slowly building against the billions spent on presidential campaigns – even among politicians themselves, reports Rupert Cornwell
Samuel West interview: The actor and director on austerity, unionisation, and not mentioning his famous parents

Samuel West interview

The actor and director on austerity, unionisation, and not mentioning his famous parents
General Election 2015: Imagine if the leading political parties were fashion labels

Imagine if the leading political parties were fashion labels

Fashion editor, Alexander Fury, on what the leaders' appearances tell us about them
Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

Phumzile Mlambo-Ngcuka: Home can be the unsafest place for women

The architect of the HeForShe movement and head of UN Women on the world's failure to combat domestic violence
Public relations as 'art'? Surely not

Confessions of a former PR man

The 'art' of public relations is being celebrated by the V&A museum, triggering some happy memories for DJ Taylor
Bill Granger recipes: Our chef succumbs to his sugar cravings with super-luxurious sweet treats

Bill Granger's luxurious sweet treats

Our chef loves to stop for 30 minutes to catch up on the day's gossip, while nibbling on something sweet
London Marathon 2015: Paula Radcliffe and the mother of all goodbyes

The mother of all goodbyes

Paula Radcliffe's farewell to the London Marathon will be a family affair
Everton vs Manchester United: Steven Naismith demands 'better' if Toffees are to upset the odds against United

Steven Naismith: 'We know we must do better'

The Everton forward explains the reasons behind club's decline this season
Arsenal vs Chelsea: Praise to Arsene Wenger for having the courage of his convictions

Michael Calvin's Last Word

Praise to Wenger for having the courage of his convictions