An Attendee Takes a Photo of a F-35 Jet at the Singapore Airshow

An Attendee Takes a Photo of a F-35 Jet at the Singapore Airshow

Brent Lewin/Bloomberg

The F-35 has become the company’s largest program, accounting for 16 percent of Lockheed’s sales in 2013, up from 14 percent a year earlier, according to federal regulatory filings.