The U.S. Navy reports that F-35C Lightning II fighters conducting test flight operations from an aircraft carrier at sea are successfully proving their capabilities.

During the first four days of a two-week Development Testing I program, the jets from Lockheed Martin performed 28 flights for a combined 34.5 flight hours and accomplished more than 75 percent of threshold test requirements.

A total of 108 catapult launches were performed as well as 215 planned touch-and-go landings, two long touch-and-go landings, and 110 arrested landings and zero bolters, or failures to catch an arresting cable on the flight deck. Night operations were also conducted.

"During DT-I, the test team has conducted a series of events designed to gradually expand the aircraft-operating envelope at sea, including crosswind and low-energy, high-wind catapult launches and approaches to test the aircraft's ability to perform in both nominal and off-nominal conditions," the Navy said.

"Testing thus far has demonstrated the aircraft's exceptional handling qualities throughout all tested launch and recovery conditions."

The testing is being conducted from the USS Nimitz, sailing off the coast of San Diego, Calif.

DT-1 is the first of three at-sea test phases for the F-35C, which is scheduled to deploy with the Navy's carrier fleet in 2018.