· Malaysian air disaster families cling to hope

The sudden disappearance of a Malaysian Airlines flight bound for Beijing has captured the world’s attention. Not only is the loss of an airliner a rare event, but the fates of 239 people remain bound up in the mystery of what happened to the Beijing-bound jet.

As we enter day five in the search for answers, The New Daily looks at the most puzzling questions in the case of MH370.

1. Why was no information transmitted from the plane before it disappeared?

What we know: Before the plane went down, no status signals or no may-day calls were sent out. Mary Schiavo, aviation lawyer and former Inspector General of the US Department of Transportation, told ABC’s 7.30 a lack of transmission suggests “a pretty significant event”.

“The plane itself gives off information, known as system status checks, back to the airline’s base all the time. Here, according to reports so far, there was no information. That’s very odd because this is a very sophisticated plane,” she said.

The plane was also off radar, perhaps due to its mid-ocean location. Radars often only transmit signal above land and it is the job of the pilot to supply radio location updates when the aircraft is off the map. The last known radio update from MH370 was apparently received by a nearby Boeing 777 en route to Japan.

What does it mean: Possibly out of range while above water, flight MH370 experienced an event so sudden it prevented distress calls.

2. Do the stolen passports indicate a terrorist attack?

Do stolen passports form part of the missing aircraft puzzle? Photo: Shutterstock

What we know: Two passengers on board the plane were travelling on stolen passports. Authorities have described the two men travelling on the passports as “non-Asian” in appearance, and civil aviation chief Azharuddin Abdul Rahman compared one of them with Italian footballer Mario Balotelli.

The tickets were purchased from a Thai travel agent by an Iranian man known only as Mr Ali. Mr Ali requested cheap tickets from the travel agent which eventually expired, requiring the agent to rebook them.

Malaysian police have confirmed one of the passengers who used a stolen passport was a 19-year-old asylum seeker with no terrorism links. It is understood he was seeking to travel to Germany.

In a statement, Interpol has contested that “only a handful of countries worldwide are taking care to make sure that persons possessing stolen passports are not boarding international flights”.

What does it mean? A terrorist attack remains a possibility but people travelling on stolen passports is common, especially in Asia.

3. Did a “fender bender” involving the same aircraft in 2012 influence the disappearance?

What we know: In 2012, the same aircraft was involved in a minor on-ground collision at Shanghai’s Pudong Airport. The crash tore about one metre of the Boeing 777’s wing tip, a defect which was repaired and cleared by Boeing and deemed safe to fly, said Malaysia Airlines CEO Ahmad Jauhari Yahya.

However, according to Ronald Bishop, head of aviation at Central Queensland University, “aviation is one of those fields were you can inspect something fully, but not find out there’s an issue until you’re a few years down the road”.

What does it mean? While the earlier collision could have weakened the plane, its impact does not appear to be in keeping with the “significant” incident experts believe would cause the plane to disappear.

4. Why did the plane make a sharp turn?

What we know: Malaysia’s military radar indicates the missing plane may have veered off its flight path immediately prior to its disappearance.

“If that’s the case,” says Mr Bishop, “they could have realised they had a problem and tried to turn around. It also matches what would happen in a stall.”

A stall, when a lack of air flow around the wings decreases lift causing the plane to fall from the sky, is characterised by a sharp turn and sudden drop. An attempt to make a U-turn due to a threat or technical failure could also have placed the plane drastically off route.

What does it mean? A sharp turn suggests a stall, an attempt to turn back due to technical failure, or an unexplained change in flight path. If the latter occurred, this could explain why current searches in the presumed flight area have returned no results.

5. Why aren’t we receiving signals from the black box?

What we know: Planes contain a “black box”, which includes a cockpit recorder and a beacon which activates upon separation from the plane. These recording devices have a battery life of 30 days and are designed to withstand 3400 times the force of gravity, according to Bloomberg. As such, it is likely that a black box could have survived even a large explosion.

The water near where the plane disappeared is reported to be around 50 metres deep, shallow when compared with other sections of the ocean. It is improbable that such shallow water could obscure a signal.

What does it mean? Either the black box was destroyed by a huge explosion, or the search is not combing the right area.

6. Where is the debris?

A Vietnamese serviceman scans the ocean for signs. Photo: Getty

What we know: “I’m really surprised they haven’t found any floating debris,” Paul Hayes, a safety expert at London-based Ascend, told Bloomberg.

When a plane breaks up at altitude due to an explosion, as in the case of Trans World Airlines flight 800 in 1996, there is a “characteristic pitting pattern” according to Ms Schiavo. This includes a widespread path of debris that is typically easier to spot.

What does it mean? A lack of scattered debris indicates that the plane is more likely to have fallen intact and broken upon impact, making it more difficult to find.