CANBERRA, Australia — The hunt for MH370 will end for good this summer if the Malaysia Airlines plane still isn't found, the chief investigator said on the eve of the second anniversary of its disappearance.
The search of a 46,000-square mile area of the southern Indian Ocean will most likely end in July, Australian Transport Safety Bureau Chief Commissioner Martin Dolan told NBC News Monday.
Three-quarters of the search zone has been completed so far. "If we don't find the aircraft within the priority search site … that's the point at which the search will stop," Dolan said.
He said the governments involved in the search — Malaysia, China and Australia — "don't have the appetite" to widen the search area, having already spent almost $100 million mapping and scanning the ocean floor.
But new discoveries of possible wreckage — one last week in Mozambique and another reported Sunday on Reunion Island — had raised optimism that they are looking in the right place, Dolan added.
In particular, the possible Boeing 777 part found in Mozambique by American lawyer Blaine Alan Gibson is of interest to the ATSB, Dolan said. Laboratory experiments would help them decide if the object a piece of wreckage, and what clues it could give them about the location of MH370, which vanished on March 8, 2014 with 239 passengers and crew on board.
"For a start you can take a look at how it floats in the ocean because all the models about how things drift in the ocean have three dimensions: currents, waves and wind," he said. "If you know how much of it is sticking above the surface, then how you factor for wind and wave changes. So then you can refine your model for drift based on that and that's the thing we'll be doing with the debris that is coming to Australia."
The Reunion Island object is still in the hands of the beachcomber who found it, a police spokesman told NBC News.
Commandant Claude Grocholski said no official investigation has been launched into the 8- by 15-inch metal object, which was found by Johnny Begue — the same man who last July found the only confirmed piece of MH370 wreckage. He added that the object had not been turned over to authorities.
Meanwhile, relatives of a dozen passengers filed a lawsuit in Beijing against Malaysia Airlines, Boeing and engine-maker Rolls-Royce. Tuesday's anniversary is also the deadline for applications for litigation under international law.
Wen Wancheng, whose 34 year-old son Wen Yongsheng was aboard MH370, said that the companies had not provided due service to the relatives and that the information shared had been insufficient.
The group's lawyer, Beijing-based attorney Zhang Qihuai, said that the ultimate goal of the lawsuit was "to find out the cause of the accident and those who are responsible."
Dolan insisted he was optimistic about finding the wreckage before July.
"I occasionally wake at night and consider whether we have done everything possible, whether we have done things correctly and then the next day I normally go and talk to various experts to just check on things," Dolan said. "We are confident we have done the best possible analysis and that we are running the search the best possible way, which is why I still remain confident of success."