PINELLAS PARK — Daniel Conroy knows the F-35 Lightning II program has had its problems, delayed for years and costing far more than first expected.

But the Pentagon's ambitious fighter jet project is finally back on track, says Conroy, director of the Air Force F-35 program for Lockheed Martin, which is building the plane.

"The program has been challenging, flight test has been difficult, but we've worked through a lot of issues," Conroy said Monday at Lockheed Martin's facility here. "We can see the light at the end of the tunnel."

Once it ramps up to full-scale production, Lockheed will make close to 200 of the fighter jets a year, up from the 45 it expects to build this year. The Government Accountability Office, initially forecast it would reach full production in 2012, but now says that won't happen until 2019.

Eventually, the company's Pinellas Park factory will start working two shifts to make the airplane's canopy — the windshield and the frame that keeps it in place. About 30 people work on the production line now, but the project will employ close to 200 at full capacity, said Scott Williams, Lockheed's Pinellas Park production manager.

Statewide, the impact will be much larger. More than 100 of the F-35's suppliers are based in Florida, and Lockheed Martin is making sensors and developing computer systems for the fighter jet in Orlando, Conroy said. In all, the company says the program will bring 13,000 jobs to the state.

The project has gotten a boost recently after years of trouble. The Marine Corps gave its initial okay to the plane over the summer, and the Air Force and Navy are expected to follow suit over the next two years. Lockheed officials hosted a demonstration of the F-35's technology for local politicians and reporters Monday to draw attention to its progress.

Its pitch: The F-35 is hugely complicated — and important. It's designed to replace the military's aging fleet of fighter jets with a plane that can be used for decades, one that combines stealth with technological advancements.

"A program of this significance is always going to have some challenges," said U.S. Rep. David Jolly, R-Indian Shores, who visited Lockheed's Pinellas Park plant Monday. "We're going to have an asset adding great value to the taxpayer that protects our men and women in uniform."

But getting to this point has been difficult for the aerospace giant, and government watchdogs say the project isn't in the clear just yet.

From design to assembly, the F-35 project is expected to cost $391.1 billion, according to the Government Accountability Office, up 68 percent from initial projections of $233 billion. And the government is expected to buy 2,457 planes, 400 fewer than first thought.

In an April report, the watchdog agency said the project had mostly gotten into line and costs have been "mostly stable" since the Pentagon changed its budget and time line in 2012. But the report was critical of the plane's engine, saying it "has a long way to go to meet program goals."

And with testing ongoing, "more technical problems are likely," the agency said. "Addressing new problems and improving engine reliability may require additional design changes and retrofits."

Those comments followed problems the F-35 encountered in test flights. Testing on some planes had to be stopped when a part of the airframe called the bulkhead started to fracture, and in June 2014, an engine caught fire because of overheating.

But Conroy defended the program's progress so far, saying that those issues were an inevitable part of testing and that Lockheed and its suppliers fixed them.

"You don't get through any flight test program, especially one as complex as this, without having a few things that you just go, 'Wow, I wouldn't have thought of that,' " he said. "But the good news is there hasn't been anything insurmountable. We've worked through things pretty quickly."

Contact Thad Moore at tmoore@tampabay.com. Follow@ThadMoore.