The man in charge of the hunt for Malaysia Airlines flight MH370 believes it is “very likely” the plane will be found in the next four months, even as the multimillion dollar search effort enters what is likely to be its final stage.

In the two years since the plane disappeared en route from Kuala Lumpur to Beijing with 227 passengers and 12 crew on board, its only confirmed trace has been a barnacle-encrusted flaperon wing that washed up on the French island of Réunion last July.

MH370 search: 'rogue pilot' theory still on Australian investigators' radar Read more

Two other pieces of flotsam, found on Réunion and Mozambique, are suspected to come from the plane, but are yet to be positively identified.

Yet Martin Dolan, the head of the Australian authority tasked with scouring an expanse of seafloor for the wreck of the aircraft, is confident it will be found this year.

Since 31 March 2014, the Australian Transport Safety Bureau has led the search effort for the plane, driven by what its investigators have always considered to be the most likely scenario – known as the “ghost flight” theory – that no-one was at the controls when the jet went down.

The ATSB’s modelling shows that, after running out of fuel, the plane would have crashed in the southern Indian ocean, off the coast of Western Australia. As of this month, four ships have searched more than 85,000sq km of a long but narrow “seventh arc”, totalling 120,000sq km of seafloor – without success.

To Dolan, that suggests that the plane is in the 30,000-odd sq km yet to be searched, and will be found when the operation concludes around July, if not before.

“It’s as likely on the last day [of the search] as on the first that the aircraft would be there. We’ve covered nearly three-quarters of the search area, and since we haven’t found the aircraft in those areas, that increases the likelihood that it’s in the areas we haven’t looked at yet.”

At this late stage, Dolan is aware that his assurance could seem like blind optimism, or a bid to save face over a US $133.3m operation – paid for by Australia and Malaysia, plus $14.8m in funding and equipment from China – that has already been said to have failed.

The search zone – twice the size of Tasmania – shows a range of places the plane could be, some higher probability than others. “We now know that there’s a range of those places the aircraft isn’t in, but that hasn’t changed the overall probability that the aircraft is in the total search area,” Dolan said.

“To eliminate that from the search – assuming we don’t find the aircraft – we have the cover the whole area.”

The complexities surrounding the search are immense: the area is six days’ sail from the nearest shore and previously unmapped, with water depths of up to 6,000m and underwater mountains, crevasses and 2,000m sheer drops. It is being covered at a rate of two knots – about walking pace.

Facebook Twitter Pinterest A waiter walks past a mural of flight MH370 outside Kuala Lumpur. Photograph: Joshua Paul/AP

Given those uncertainties, Dolan can’t be specific about when the search will be completed. But he remains optimistic. “We’ve still got some serious area to cover, including some areas in the assessment that are highly prospective for finding the aircraft, and the aircraft’s very likely there.

“We’ll cover those very thoroughly and I hope our next conversation is going to be about how we found the aircraft.”

He draws his confidence from the robustness of investigators’ analysis of the plane’s last satellite communications. What looks like obscure technical language is expressing a “very reliable proposition”, he says, which the ATSB has sometimes struggled to communicate to laypeople. “And that is why there’s not always a good understanding of why we’re so confident in what we’re doing.”

The model may be perfect, but it is only as accurate as its input data. And that’s where the ATSB’s singleminded approach falls short, says journalist Jeff Wise, a member of the so-called Independent Group (or IG) of professionals conducting their own work on the search for MH370. While the ATSB’s “ghost flight” theory is the most simple, most reasonable, most likely explanation of what happened, it is not the only one.

“The ATSB has essentially spent $130m to rule that out,” he says. “And as the more reasonable hypotheses get ruled out, we have to move further down the list to look at ones that seem more outrageous.”

One such theory is that the plane’s systems were tampered with so that it only appeared to be going south. That factors into Wise’s own hypothesis, which he posted in a six-part blog post last February: that the plane was hijacked on Vladimir Putin’s instruction.

His “spoof” theory got “a respectful hearing but no converts among the IG”, he wrote in a 4,000-word feature for New York magazine: “My gut still tells me I’m right, but my brain knows better than to trust my gut.”

With the end of the search in sight, every day that it does not throw up the plane casts doubt in the minds of even those who take the “ghost flight” theory as given. “Some of the people who believe it has to be in the search box are thinking they’ve probably missed it,” says Wise.



The example he gives is of mowing a lawn: in theory, you can cut every single blade of grass. But it’s very easy to leave gaps, even if you are systematic and precise.

Correspondence seen by Guardian Australia shows that a short section of a search line approximately 24km west of the seventh arc was missed when the vessel Fugro Discovery’s survey on 4 September was cut short by poor weather.

Facebook Twitter Pinterest Flight officer Rayan Gharazeddine on board a Royal Australian Air Force AP-3C Orion searches for missing Malaysia Airlines Flight MH370. Photograph: Rob Griffith/AP

Independent investigators Richard Cole and Brock McEwen, who flagged the apparent oversight with the ATSB, were initially told that the area had been accounted for. But on 3 December, operational search program director Peter Foley emailed to correct that statement, clarifying that approximately 80km had been missed and was “earmarked to be rerun”.

It was later scanned, said Cole, though there was no evidence to suggest that this was a result of his or McEwen’s work.

Dolan says the ATSB’s approach has been dynamic, transparent and and informed by regular correspondence with the Independent Group. “They provide a criticism and questioning that is very valuable to us. That’s one component of the wonders of the internet.”

Less welcome is the correspondence – often “quite insistent”, he says – from those whose theories cast doubt on the operation “with no real reason”. “We will listen to anyone, but the more they insist on things that are inconsistent with the facts, the less we’re going to pay attention to them.”

The most promising development in some time may have been made by a 58-year-old lawyer from Seattle, Washington, with no relevant professional expertise or accreditation.

Blaine Alan Gibson has spent much of the past year travelling in the Indian ocean region, attempting to solve the mystery of what happened to MH370. On 27 February he made his most exciting discovery yet: a 1m piece of metal, washed up on a sand bank in Mozambique.

It will shortly arrive in Canberra for testing. Until that is complete, Dolan says he cannot comment other than to say he is “certainly very interested” in what the debris may prove to be. The location, at least, is consistent with drift analysis, and the Malaysian transport minister said on Twitter there was a “high possibility” it belonged to a Boeing 777.

Based on the experience of the flaperon, Dolan warns to “not have too many expectations”: even if it is found to be from MH370, it would not necessarily lead to the plane.

In the absence of significant developments, the hunt for MH370 will end with the completion of the 120,000sq km zone, slated for around July. If the plane has not been found, says Dolan, “the alternative scenarios might apply”.

These include the “controlled glide” theory, in which someone was in charge of the plane when it went down, and would implicate an area three times as big. The Australian, Malaysian and Chinese governments have been fairly explicit that the cost of searching such a vast tranche of ocean floor is prohibitive.

Whether or not the plane is found in that last 30,000-odd sq kms of seabed, investigators will have to take the available evidence, however insubstantial, and put forward their best guess as to what happened in the final moments of flight MH370.

“At some point, whatever the total of the evidence is, is going to have to be assessed and a conclusion reached as to the most likely solution to the mystery,” says Dolan.

“That’s the way we see our job. That’s the way our Malaysian colleagues see their job. And that will happen. The only question really is, how extensive that information will be.”