SAN DIEGO (AP).- It was a surprising image for the fisherman hoping to find bass on his electronic fish finder: The outline of an airplane submerged 85 feet below the surface of a San Diego reservoir.

Navy divers later confirmed it was a rare World War II dive bomber that crashed after its engine failed during a training exercise on May 28, 1945.

The pilot and gunner aboard managed to ditch the craft and swim ashore to safety. But the plane remained at the bottom of the lake, forgotten for six decades until it turned up last year on the angler's device.

Now private salvage divers have been slowly and gently clearing away the silt and mud covering the SB2C Helldiver. They hope to pull the craft out Thursday — 65 years after it plunged into the cool waters.

If it can be restored, the National Naval Aviation Museum hopes the Helldiver fills a void in its collection, considered to be one of the world's largest displays of naval aviation history with more than 150 planes.

"We've been looking for a Helldiver for quite some time," said Navy Capt. Ed Ellis, of the museum in Pensacola, Fla.

Only a handful of the 5,100 dive bombers manufactured during World War II still exist.

"At the end of the war, they were obsolete and so they just chopped them down, melted them and made most of them into tin cans," Ellis said. "It wasn't a particularly good airplane."

One of the Helldiver's nicknames was the "Beast," because of its reputation for being difficult to handle.

The aircraft was plagued by problems from the start with the first prototype crashing in February 1941. The second went down as well when it was pulling out of a dive.

The British Royal Navy and the Royal Australian Air Force canceled their orders.

The U.S. military sent untried planes to recently commissioned carriers, some of which saw disastrous results with wing folding mechanisms failing, bouncing tailhooks, leaky hydraulic lines and collapsing tail wheels.

Over the years, the Curtiss-Wright Corp. implemented a total of 96,675 engineering changes during the war to correct the problems and meet Navy requests to make it more combat-worthy. By the war's end, the aircraft overcame most of its woes and had proven itself in action, experts said.

San Diego shut down the Lower Otay Reservoir to the public during this week's salvage operation.

Taras Lysenko, a former Army ranger who has rescued 33 planes for the museum, said divers found the Helldiver covered in mud and silt that kicked up in the reservoir, which slowed their efforts to extract it.

Divers have been working with zero visibility while they prepare the plane to be lifted carefully out of the water without further damaging it. Lysenko said he expected the plane would emerge from the water Thursday.

Crews also have been keeping an eye out for anything bubbling to the surface that could indicate oil or fuel was leaking out and contaminating the city's drinking water.

One of the people expected to be on hand to witness the event will be the son of pilot E.D. Frazar, who crashed into the reservoir with the gunner, Lysenko said.

"Wouldn't it be amazing to watch it being pulled up, or to actually have it restored to flying condition, and I could sit in my father's pilot seat and take the plane up?" Richard Ansel Frazar of Texas, son of the pilot, told the San Diego Union-Tribune last year.

A former volunteer at the museum left money to cover the cost of the plane's extraction, Ellis said. The museum only salvages planes in which the crew survived. If anyone died, the site is considered to be a grave and is not touched, he said.

The museum has located hundreds of submerged aircraft, mostly in Lake Michigan and some oceans.

"This is always an exciting event. Some aircraft have been pulled up and we've found the batteries still hold a charge, or there is still water in the canteen left by the pilots in the cockpit, or some of the lights still work," Ellis said. "We're always amazed by what still works and is in good condition."


Copyright 2010 The Associated Press.