MH370: What we know about the flaperon aircraft debris discovered on Reunion

The discovery of an aeroplane part on the island of Réunion in the Indian Ocean is being investigated to see if it belongs to the missing Malaysia Airlines flight MH370, 16 months after the aircraft disappeared.

The Boeing 777 vanished while travelling from Kuala Lumpur to Beijing with 239 passengers and crew on board on 8 March 2014.

Aviation experts have speculated the two-metre long aircraft part, identified by investigators as a flaperon, is likely to have come from the wing of a Boeing 777.

Malaysia's deputy transport minister Abdul Aziz Kaprawi said the part is "almost certainly" from that type of plane. Warren Truss, Australia's deputy prime minister, said the photographs showed a part "not inconsistent with a Boeing 777" but said there are "other possibilities".

Malaysian officials have urged caution and say more evidence is needed to confirm the debris is from MH370.

What is a flaperon?

A flaperon is a type of aircraft control surface that is a combination of a flap and an aileron. Flaps are devices mounted on the trailing edges of wings to reduce the speed at which the aircraft can safely be flown and to increase the angle of descent for landing, so they shorten take-off and landing distances.

An aileron, also mounted on the wing, is used to roll a fixed-wing aircraft left and right. In additional to controlling the roll and bank of an aircraft, as do ailerons, flaperons can be lowered together to function in a similar way to a dedicated set of flaps.

The aircraft part was spotted by workers cleaning a beach at Saint-André in the east of Réunion, who did not immediately realise the debris could be a significant lead in the search for MH370.

What do we know about the debris?

Australia's deputy prime minister Warren Truss said a code discovered on the part, BB670, could be a maintenance number but not a serial number. Other reports said the number was BB670.

The aviation website AirLive.net has said that one of the codes reportedly stamped on the debris matches a Boeing 777 flaperon.

The Guardian reported that Boeing's Aircraft Maintenance Manuel states the code "670" refers to a zone of part numbers relating to the aircraft's right wing, including the flaperon. Analysis of the number on the flaperon should trace the fragment back to an individual aircraft.

The Journal de L'île de la Réunion said experts had identified the type of barnacle on the part by analysing the photographs. According to the newspaper, the species is Lepas anatifera, commonly known as the pelagic or smooth gooseneck barnacle, which is found in tropical and subtropical seas. Experts will analyse the barnacles to see how long the wreckage was in the water.

A journalist from the same newspaper reported the remnants of a damaged suitcase had also been found, but it is unconfirmed whether the luggage had any connection to MH370.

Where is Réunion island?

Réunion is a small French island located in the Indian Ocean around 600km (370 miles) east of Madagascar. The wreckage was discovered on the western coast of the island in the region of Saint-André.

The debris was found about 6,000km (3,700 miles) away from the Australian search site in the southern Indian Ocean, where search efforts have been concentrated since the disappearance of MH370.

Investigators have said it is realistic the aircraft piece may have drifted from the 60,000sq-km area south-west of Perth, where the Australian-led search has been ongoing.

If investigators prove the flaperon is from a Boeing 777 it is likely to be from MH370 as no other 777s have crashed in the southern hemisphere, but it is not confirmed if the part is from the Malaysian plane.

However, the BBC reported other large aircraft have crashed near Réunion in that region of the Indian Ocean, including an Airbus 310 belonging to Yemenia Airways in 2009.