(CNN)—For the first time, Air Force F-35A Joint Strike Fighters have dropped bombs during training, the Air Force announced, marking a key milestone in the path toward combat readiness. Airmen from the 388th and 419th fighter wings dropped the laser-guided bombs at Hill Air Force Base in Utah last week.

"This is significant because we're building the confidence of our pilots by actually dropping something off the airplane instead of simulating weapon employment," Lt. Col. George Watkins said in an Air Force statement. It's the first time such bombs had been launched with jets designed to deploy after so-called initial operational capacity. IOC is declared when the planes are deemed ready for combat. The first F-35s -- a Marine squadron was declared ready for combat last August . That first IOC was initially scheduled to be declared operational in 2012, but that target date was delayed after a series of setbacks. The F-35 program's current price tag is $400 billion and is expected to cost $1 trillion over its entire life.

The Pengaton doesn't know The F-35's aviation technology ranks among the most sophisticated in the world -- designed to conduct air-to-air combat, air-to-ground strikes, intelligence, surveillance and reconnaissance missions. It's also designed to allow pilots to immediately share data with one another and their commanders; it can penetrate enemy territory without being detected by radar; and its specialized helmet display gives pilots a 360-degree view of their surroundings. The F-35 is also known as the Joint Strike Fighter because it's intended for use by the Navy, the Marine Corps and 10 foreign countries, in addition to the Air Force.