The complex job of lifting the stricken Flight 5432 from the Potomac River is due to begin Monday, with local and state officials promising that they will recover all 67 of the victims who died when the plane crashed into a military helicopter last Wednesday.

So far, 55 victims’ remains have been recovered. D.C. Fire and EMS Chief John Donnelly told a news conference Sunday: “We’re going to recover everyone.”

“If we knew where they were, though, we would already have them out, so we have some work to do as the salvage operation goes on, and we will absolutely stay here and search until such point as we have everybody,” he added. Recovery workers have been battling difficult conditions with near-zero visibility in the dark waters.

The U.S. Army Corps of Engineers, Baltimore District, plans to lift the remains of the jet from the river in stages, a process that is expected to last three days.

The operation will use a crane barge, deck barges, dive boats and two surface-supplied dive systems, the army said in a statement.

The wreckage will be taken to a hangar for the National Transportation Safety Board to continue investigating the cause of the collision.

Then the recovery teams will turn their attention to the remains of the Black Hawk helicopter. The “large lifts” portion of the operation is expected to be finished by Saturday, with the clearance of other debris lasting until at least Feb. 12. An automatic stop on this work will be ordered when a body is discovered.

“The level of coordination both behind the scenes and out on the Potomac is exceptional,” said Baltimore District Commander Col. Francis Pera. “We have not and will not lose focus of what is most important — the safety of our crews and accounting for those still missing to bring closure to their families and loved ones.”

The recovery timeline is, however, dependant on the availability of lifts, as well as weather and the tides.