The U.S. Army is investigating why the latest test of the Patriot Advanced Capability-3 (PAC-3) missile system apparently failed to achieve an intercept.

During the Nov. 11 test at White Sands Missile Range, N.M., two PAC-3 missiles were fired about 8 a.m. Mountain time against a legacy Patriot missile modified to represent a short-range ballistic missile target. But preliminary data show that an intercept did not occur, the Army said.

Although the Army had better luck in a similar test in September, when it also fired two PAC-3s at a Patriot-as-a-target, (DAILY, Sept. 9), there were several planned differences between that test and the one that just occurred, Army spokesman Bob Hunt said. The target in the latest test had a different flight profile than the one used in the previous test. In addition, the more recent test used a newer version of the PAC-3 missile than the one used in the earlier test.

With the latest failure, the PAC-3 missile has now been unsuccessful in three of 20 intercept tests. The most recent test was designed to try out software upgrades to the missile and ground system.

Lockheed Martin builds the PAC-3 missile and Raytheon supplies the Patriot launcher and radar. Spokesmen for both companies referred requests for comment to the Army, whose Program Executive Office for Missiles and Space manages the program.