The widow of a US Navy pilot who died when his fighter jet was struck by a Patriot missile during the 2003 invasion of Iraq has sued the air defense system's maker, Raytheon (RTN) Co.

The lawsuit, filed in federal court in Boston on Tuesday, alleges the company was negligent in the design and manufacture of the Patriot system. It claims the Patriot was prone to malfunctions that misidentified U.S. planes as enemy missiles that "occurred with alarming frequency and were well-known to Raytheon before the incident."

A spokesman for the defense contractor, based in the Boston suburb of Waltham, said company lawyers had not had a chance to review the case and could not comment, The Boston Globe reported Wednesday.

The lawsuit by Lt. Nathan White's widow, Akiko Ohata White, who also is suing on behalf of their three children, does not name the U.S. Army or other military entities that developed and used the Patriot.

The military is immune from most lawsuits by service members and their families. The U.S. Supreme Court ruled in a 1988 lawsuit that government contractors also have broad immunity from liability as long as they follow general specifications.

William O. Angelley, an attorney for the White family, acknowledged the difficulty in suing the government in the case, and said the family's claims against Raytheon have merit based on publicly reported Army investigations of White's death.

"Based on our analysis of the Army investigation, it is undisputed that the root cause of this tragedy is a serious design flaw in the Patriot missile system," he said.

The Globe said it could not immediately reach Akiko White, who is living in Japan, for comment. Nathan White grew up in Abilene, Texas.

The Patriot, originally designed to shoot down aircraft, gained attention in the first Gulf War when it was used against Iraqi scud missiles.

There were three friendly-fire incidents, two of them fatal, involving the Patriot. Nathan White was killed on April 2, 2003, while returning to his aircraft carrier from a bombing mission. Two British pilots were killed in the second incident.

A report the Army gave to White's family in December 2004 said the Patriot system, despite past efforts to correct the problem, frequently gave false symbols of potential targets that soldiers were not properly trained to expect and deal with. White's plane was apparently was mixed up with one of the "false tracks" and misidentified, it said.

Raytheon has declined to respond to the report in the past except to say it was "confident that the Patriot system performed as designed," the Globe reported. An Army spokesman said Tuesday it was not likely to comment about ongoing litigation.