Raytheon has won a $450 million contract to launch development of the small diameter bomb increment II (SDB II) for the US Air Force and Navy, a competitive triumph over a Boeing/Lockheed Martin team that seemed to be the early favourite for the award.

The award gives Raytheon a key position in the hotly contested market for an all-weather munition that can strike targets on the move. The weapon will be integrated on the US military's most advanced tactical strike aircraft - the Boeing F-15E and Lockheed Martin F-35B and F-35C.

Raytheon says the company is "pleased" by the contract award, but declines further comment until a press conference scheduled next week.

The key technology in the competition to deliver the 113kg (250lb)-class SDB II is a tri-mode seeker, with electro-optical, semi-active laser and millimetre wave radar on board. In bad weather, the weapon could shift terminal guidance from the laser to the radar, allowing the SDB II to strike stationary or moving targets even in bad weather.

Boeing originally won the SDB contract in 2003. The programme was split into two increments after it was revealed that former air force acquisition official Darleen Druyun steered the contract to Boeing as a "gift" in return for future employment.

Shortly afterward, Raytheon entered the competition after the only two previous SDB competitors - Boeing and Lockheed - decided to team up.

The Boeing team planned to offer the SDB Increment 1 body with a tri-mode seeker derived from the terminated Lockheed Joint Common Missile (JCM).

Meanwhile, Raytheon adapted a tri-mode seeker originally developed for the US Army's iPAM precision attack missile programme, which was also subsequently cancelled.

The SDB II contract is awarded as the army enters the last few months of the competition for the joint air to ground missile (JAGM) contract, which replaces JCM. JAGM is a competition between a Raytheon/Boeing team and Lockheed, and also involves a weapon with a tri-mode seeker.

Source: Flight International