After some technical problems, the search for the wreckage of Amelia Earhart’s Lockheed Electra has begun near the reef slope off the west end of Nikumaroro, a tiny uninhabited island between Hawaii and Australia where the legendary aviator may have landed and died as a castaway 75 years ago.

The International Group for Historic Aircraft Recovery (TIGHAR) is carrying on the the hunt, which relies on a torpedo-shaped Autonomous Underwater Vehicle (AUV) called Bluefin-21 and a Remote Operated Vehicle (ROV).

While the AUV is capable of simultaneous multi-beam and side-scan data collection and black-and-white still photography down to 4,921 feet, the ROV — a TRV 005 robot made by Submersible Systems Inc. — is capable of reaching depths of 3,300 feet. This is the depth the reef slope reaches more than a mile out from the reef edge.

PHOTOS: Inside the Search for Amelia Earhart

WATCH VIDEO: Find out how the search for Amelia will be carried out.

Since their arrival aboard the University of Hawaii oceanographic research ship R/V Ka Imikai-O-Kanaloa four days ago, TIGHAR researchers have tested the equipment, solved several technical problems, organized the way the deep-water search is conducted and finally taken the plunge.

“During nighttime hours the AUV flies down the reef slope to collect data. The ROV team runs during the day, doing visual searching and looking at anything the AUV has found,” Ric Gillespie, TIGHAR’s executive director, said.

Watching the ROV feed is not as exciting as it might seem.

“It’s tedious work. Your eye sees things and wants to make sense of them in a human way, you look at coral and rocks and your eye tries to interpret them as man-made objects,” Gillespie said.

He added that many flat coral surfaces with right angle corners resulted in numerous false alarms.

Get Full Coverage of the Amelia Earhart story here.

During various six-hour missions, the ROV has so far identified only debris belonging to the British steamer SS Norwich City, which went aground on the island’s reef in 1929.

“At about 1050 feet they found old-fashioned bottles. At 1,000 feet they found a ship’s propeller, a huge (8 feet across), four-bladed, apparently iron or steel, prop with squared-off blades,” Gillespie said.

The main body of the wreckage, a huge towering hunk of bent and twisted steel and iron, rests on the ocean bottom at 980 feet.

No plane debris has yet been found, but the search has just begun.

“There is still a lot of ground to cover. The weather is holding good, the sea is calm, which makes working the technology much easier,” Gillespie said.

“Everyone was hoping for a quick find, but of course it is the slow solid approach that works,” he said.

Click here for more background and updates on TIGHAR’s expedition to Nikumaroro.

Photo: The torpedo shaped Autonomous Underwater Vehicle (AUV) and the Remote Operated Vehicle (ROV). Credit:TIGHAR.