The U.S. Air Force announced the deployment of the E-3 Sentry Block 40/45 to a combat theater of operations, after the arrival of the first upgraded system in Southwest Asia.

The deployment follows the most extensive modification to the aircraft's weapon system since defense contractor Boeing first delivered the craft in 1977. The craft's $2.7 billion upgrades replaced 1970s hardware and software, enhancing the system's surveillance, communications, threat-detection and other capabilities.

"This modification represents the most significant upgrade in the 35-plus year history of the E-3 and greatly enhances our crewmembers' ability to execute the command and control mission, while providing a building block for future upgrades," said Col. David Gaedecke, 552nd Air Control Wing commander at Tinker Air Force Base and E-3 pilot.

Nine of the Air Force's 27 E-3 Sentry aircraft assigned to the 552nd ACW have been modified. Gaedecke says the modified aircraft will be used to process tactical information for combatant commanders to increase situational awareness. Until Friday, the Air Force says the aircraft have been used in counter-drug and homeland defense missions as part of Operation Noble Eagle.

The E-3 Sentry is an airborne warning and control system typically known for its signature rotating radar dome mounted on top of the craft. The system provides accurate real-time intelligence information of friendly, neutral and hostile activity in the battlespace to the Joint Air Operations Center. It can also supplement fighter-interceptor aircraft against enemy targets and provide reconnaissance information to ground forces in support of air-to-ground operations.

"What the E-3 brings to the fight is essential to our combat commanders, both in the air and on the ground," Gaedecke added.

The E-3 Sentry will begin flying combat missions immediately.