Important tests loom for Navy and Marine Corps F-35.

• Author: Insinna, Valerie
• Position: Cover story

The Navy and Marine Corps variants of the joint strike fighter have an eventful year ahead, and program officials are saddled with a long list of work to do before major milestones in the summer.

The Marine Corps' F-35B is planned to be introduced to the fleet on July 1, the first of the expensive, controversial joint strike fighter variants to achieve initial operating capability. Stakeholders are watching closely to see if the military will be able to meet its target date on schedule, as well as whether the jet's performance will help vindicate the massive cost of acquiring it.

Meanwhile, the Navy's F-35C will undergo its second round of sea trials aboard the USS Dwight D. Eisenhower aircraft carrier, another big step toward readying the platform for fielding in 2018.

Program managers from both the military and F-35 manufacturer Lockheed Martin said they were under pressure to move quickly in order to meet schedule demands without putting the program at risk.

You want to be able to run as fast as you can, but in running fast, you don't want to make mistakes, because mistakes will set you back much further than if you had been going slowly, said Art Tomassetti, Lockheed Martin's program manager for the B-variant and a former Marine Corps colonel.

The military's F-35 program manager, Air Force Lt. Gen. Christopher Bogdan, believes the joint program office will be able to meet its July deadline for the Marine Corps' initial operating capability, he told reporters in October. But there's much to be done before then.

"July 1, 2015 is a tough date to hit. We've got a lot of risks that we're trying to manage and get through," he said.

If schedule slips push back the IOC date, it will be a delay of days or weeks, he added. "There's no way in the world we're missing that by months. It's not going to happen."

Thomas Donnelly, a defense and security policy analyst at the American Enterprise Institute, said he has little doubt that the Marine Corps will deploy its initial aircraft on schedule.

"They're going to bust their behinds to try to make it for a couple reasons," he said. "There's so much tension. The program has been so controversial. But the Marines are really committed to it, and I also think they know that the B-variant is going to end up being a really big deal.... When that thing goes into service, people are going to learn to love it."

Even if the program office makes its projected IOC on schedule, that title is only "cosmetic," as the...