For 18 months before it was deployed to Iraq, a combined Illinois-Iowa National Guard helicopter unit reported to the Army that most of the unit's helicopters lacked basic missile defense systems.

Despite that, the Army sent the Chinook helicopters to Iraq and used them in missions.

"There is clearly a dispute about the information that was given from the Guard to the Army before mobilization," Sen. Dick Durbin, D-Ill., said yesterday. "I cannot understand how that unit can be activated with only three of 14 helicopters properly equipped."

Since at least October 2001, the Bartonville, Ill.-based Guard unit had reported that 10 of its 14 helicopters lacked basic missile defense systems, a spokeswoman for the Illinois National Guard said.

"We clearly reported it and showed the unit's deficiencies," said Lt. Col. Alicia Tate-Nadeau of the Illinois National Guard. "The information was there for them to view."

She was responding to the suggestion made this week by Army officials that the Guard unit had misrepresented itself as ready for deployment to Iraq, setting off a last-minute scramble by the Army to find missile defense systems for the helicopters just before they were shipped out from Corpus Christi, Texas. Several of the newly acquired systems, however, arrived damaged.