In an interview with Al Jazeera, Tom Ballantyne, an aviation expert, said Abbott's announcement could be "the most promising" development since the plane disappeared.br br "Although the word caution, I think, is the most important one here," he said from Sydney. "We've had so many false leads in this story, and we probably have to wait for several hours, before we get a real defining detail of what these objects are in the water.