But Sullenberger said investigators have "a huge advantage" in this case. "The plane and most of its components have landed on an airport and are immediately accessible. It's not on the floor of the south Atlantic like Air France 447. They have the crew members who survived and are able to be interviewed ... It makes it much more likely that we will eventually find out exactly what happened, how it happened, and why it happened."
Curtis said he is also confident about the process.
"The United States has a habit of spending whatever it takes to finish an air crash investigation. When Trans World Airlines Flight 800 crashed into the Atlantic in 1996, we had thousands of government agents, a little army of people taking wreckage off of the ocean floor.
"So in this case, I'm certain we'll find everything we need for a definitive conclusion. They will have plenty of everything they need to get this thing done."