It’s been two months since Malaysia Airlines Flight 370 vanished from the sky, and as the search for the missing plane enters a new phase, experts say discovery of the aircraft could still be months or years away.

“The fact they haven’t found anything after two months in this circumstance isn’t surprising," Brad deYoung, professor of oceanography at Memorial University in St. John's, told CBC News on Wednesday. "And if anybody was offering that 'Yes we would find it quickly,' then they’ve never done this before."

“A lot of the talking heads on this — I saw a few people and I would just laugh when they would say things," deYoung said. "Their enthusiasm and their expectation for success were completely unrealistic initially.”

DeYoung said the plane, which disappeared on March 8 during a flight from Kuala Lumpur to Beijing, is certainly "findable" but the search poses many challenges.

The deep and vast search area may seem like the biggest obstacle in locating the plane. But wreckage from the Air France Flight 447 crash in 2009, which was eventually located, also covered a large search area. The difference is that officials had a pretty exact idea where Flight 447 when down.

"I think the biggest challenge is they really don’t have a good fix on where [MH370] ended," Mary Schiavo, aviation analyst and former inspector general of the U.S. Department of Transportation, told CBC News. "No one went looking for the plane on a timely basis so they had any hope of finding where it went down."

"They certainly won't find it in the next couple weeks or couple months," Schiavo said. "There’s lots of other places to look before I’d say it’s not possible to find it. I’m still hopeful that they will find it."

The intensive hunt for the plane has incorporated a search of nearly 4.64 million square kilometres of ocean and utilized more than 33 search flights, translating to over 3,000 hours spent in the air.

Australian Transport Minister Warren Truss, speaking to reporters earlier this week, gave a rather blunt assessment of their search efforts thus far.

“Unfortunately, all of that effort has found nothing,” he said.

“Any commentary about when we're likely to find this aircraft has to be just that — commentary,” he added. “We obviously have no idea when it's likely to be found, we just always hope it's tomorrow. But so far our very, very best leads, days when we were quite confident that this was going to be the day, have all proved fruitless, and so I think it would be unduly optimistic to name a day or a time.”

'Intensified undersea search'

Meanwhile, in the coming weeks, the search will transition “to an intensified undersea search” of a 60,000-square-kilometre patch of seafloor in the Indian Ocean off western Australia and where sounds consistent with a plane's black box were detected in early April.

The area became the focus of the hunt after a team of analysts calculated the plane's likeliest flight path based on satellite and radar data.

Officials will continue to use the unmanned sub Bluefin-21, an autonomous vehicle being lent out by the U.S. Navy.

But deYoung said the Bluefin-21 has its limitations. It has to be lowered down and brought back up every day, have its batteries recharged, and all its data downloaded and examined.

“They’re good, they work well, they don’t move that quickly and they don’t cover huge areas," he added.

Officials are hoping to use more specialized equipment that can dive deeper than the Bluefin vessel, and that will be able to send information back to crews in real time. 

"If they’re in the right area, then slow and steady wins the game maybe and maybe Bluefin on its own is fine," deYoung said.

Part of the problem is the search crew is in unchartered waters and no one really knows exactly how deep the water in the search area is. 

Who will foot the bill?

“If you knew the initial region you could easily program your vehicle and your survey, because you know what you’re going to find, more or less. And then you're just looking for an airplane," deYoung said. "Right now they’re probably doing the first really detailed sea bed maps that have ever been done there."

But all this is costly and has raised questions as to who will foot the bill.

"What I’m worried about is the [Malaysian] government not going to pour any more money to Malaysia Airlines," Schiavo said. "So if they stop funding the airlines, how committed are they going to be financially to this investigation?"

Cost estimates for the first phase of the search have hovered around $50 million, with the second phase pinned at another $60 million. But most experts predict the costs could end up being in the hundreds of millions of dollars

“I think they’re at a crossroads in terms of where to get equipment to do it and where to get money," Schiavo said.

Truss suggested there will be future discussions about cost sharing with Malaysia, China and other parties, including companies like Boeing and Rolls Royce, who may have vested interests in what happened.

He said they will also seek out international partners to acquire more equipment, and that the majority will have to be provided by the private sector.

"Clearly they now realize that this is going to be an 'in for the long haul' kind of a search," deYoung said.

"If they open up their search radius significantly in the next phase then that might be a sign that they're not completely confident the pings were from the plane. And if that’s true, now the time scale for the searching goes up from a few years to many years and many ships."

With files from The Associated Press