Divers in California are preparing to extract a rare World War II airplane from a San Diego city reservoir more than six decades after it crashed during a training exercise.

The National Naval Aviation Museum is funding the salvage operation that is expected to pull the SB2C Helldiver out of the water on Thursday.

The museum says the dive bomber is one of only a handful in existence.

Capt. Ed Ellis says pilots scorned the Helldiver because it was difficult to handle and was plagued with engineering problems.

Salvager Tara Lysenko says extracting the plane has been slow because it is filled with mud and silt that is blocking divers' visibility.

The son of the pilot who survived the crash will be on hand to see the plane.