After a protracted developmental test period, Raytheon plans to conduct its first operational test firing of the Advanced Medium-Range Air-to-Air Missile (Amraam) 120D this month, says Harry Schulte, vice president of air warfare systems at the company.

Company officials had been working on a fix once software was “getting hung up” in the missile, which marries an advanced radar seeker and datalinking capability with new countermeasures. The D is to be the premier air-to-air missile in the Pentagon’s arsenal once it is fielded. Schulte equates the problem with a computer freezing during use, requiring the operator to conduct a reboot. “It probably was going to be an irritant in OT,” or the operational test period, which will kick off with the forthcoming test shot this month. This prompted the U.S. Air Force and Navy, the current customers, to push for a fix and regression testing prior to entering the formal OT phase. It is unlikely the D will be available for international sale.

Schulte says that the mean-time between occurrences of the software glitch has improved, though he acknowledges the issue could crop up in the OT phase.

If it occurs in flight, the F-15 series of aircraft are designed to better deal with the problem because they allow for the pilot to go weapon station by weapon station to reset the missile. This process, however, is more complex owing to the architecture of the F/A-18 series of aircraft, he notes.

OT is expected to last about 18 months.

In the meantime, deliveries of the seekers on the C7, the precursor and international offering that preceded the D, as well the D continue, Schulte says. The program was conceived to embrace concurrency between development and production.

Another snag, however, has been performance by Alliant Techsystems (ATK), the AIM120 rocket motor provider, in passing acceptance testing, especially for firings at a stressing 165-deg. “They no longer have margin at that really low firing temperature,” Schulte says, but there is “no smoking gun” to indicate the cause. Several lots have not passed, prompting Raytheon to establish a second source for the motor in Norway’s NAMO.

Roughly 180 of ATK’s motors have been deemed suitable. NAMO has delivered 15 motors; by year-end the European company could deliver as many as 100.

Meanwhile, project officials are waiting to see the result of a test of Raytheon’s last pour this month of the motors.

Ultimately, Schulte suggests that ATK may have to reformulate the fill to provide more margins in various performance scenarios. Raytheon has been stockpiling the front end of the missile, which includes the seeker, though motor deliveries have been at a trickle. At least 200 D-model seekers are awaiting motors with more than 500 C7-models also lined up for the motor.